Biology 121 Lab

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CELLULAR RESPIRATION

 

 

What is CELLULAR respiration?

chemical E (glucose) + O2 → “biochemical currency” (ATP)

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + E

  Oxygen (O2) is ESSENTIAL for AEROBIC respiration…

  4 main steps…1 is common to both aerobic AND anaerobic respiratory pathways…

 

 

Aerobic vs. Anaerobic Respiration

  Aerobic   requires O2   4 main steps   yields up to 38 ATP glucose-1   obligate aerobes, facultative anaerobes

  Anaerobic   NO O2 required   1 main step   yields 2 ATP glucose-1   obligate anaerobes

 

 

The Mitochondrion

•  Glucose is broken down in the cytoplasm •  Kreb’s Cycle occurs in the matrix •  Electron transport occurs in/on the cristae

(envelope)

 

 

Aerobic Respiration

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + E

Step 1: Glycolysis (“glyco” “lysis”; cytoplasm)*

glucose → 2 pyruvate + 2 ATP + 2 NADH2 (6C) (3C)

cytoplasm

glycolysis

 

 

Step 2: Pyruvate Oxidation (mito matrix)

2 pyruvate → 2 Acetyl CoA + 2 CO2 + 2 NADH2 (3C) (2C)

pyruvate oxidation

matrix

 

 

Step 3: Kreb’s Cycle (aka TCA Cycle or Citric Acid Cycle; mito matrix)

2 Acetyl CoA + 2 Oxaloacetic Acid (2C) (4C)

2 Citric Acid + 4 CO2 + 2 ATP + 6 NADH2 + 2 FADH2 (6C)

Kreb’s Cycle

matrix

 

 

Step 4: Oxidative Phosphorylation (aka e- transport; mito cristae)

  NADH2 + FADH2 are involved with e – transport

  donate e- to carriers in the transport chain   pumping of H+ ions → [ ] gradient   generation of ATP

  O2 is the final e- acceptor oxidative phosphorylation

cristae

 

 

out

in

mito matrix

intermembrane space

NADH2 & FADH2

ATP synthase

 

 

Summary   3 ATP per NADH2 (x 10) (= 30; steps 1-3)   2 ATP per FADH2 (x 2) (= 4; step 3)   4 “substrate-level” ATP (= 4; steps 1 & 3)

38 TOTAL glucose-1

  Theoretical maximum = 38 ATP…no system is perfect!

∴ this number is rarely [if ever] achieved…

 

 

Anaerobic Respiration

glucose → 2 pyruvate + 2 ATP + 2 NADH2 (6C) (3C)

2 lactate 2 ethanol + 2 CO2 (= fermentation) (3C) (2C)

– animals – plants – microbes – microbes

demand > O2 release of metabolic poison

 

 

5.1 Respiration in Peas Protocol 5.1: Germinating vs. Non-germinating

⇒  Atmospheric/background CO2 level = 350-400 ppm

1.  Obtain 25 germinating peas & blot dry 2.  Place the peas in the respiration chamber 3.  Place the CO2 sensor in the chamber 4.  Wait 1 minute → begin collecting data for 5 minutes 5.  Measure & record the weight (g) of the peas 6.  Place the germinating peas in a beaker and place on ice for 5 minutes 7.  Follow the instructions on pg. 4

  determine the rate of respiration (slope, m = rate; ppm CO2 min-1)   store the data for comparison with other measurements

15.  Rinse and dry chamber 16.  Place the CO2 sensor in the chamber with non-germinating peas 17.  Wait 1 minute → begin collecting data for 5 minutes 18.  Follow the instructions on pg. 4

  Use a notebook to “fan” (i.e., clear) the sensor for 1 minute, returning the CO2 level to 300-400 ppm between EACH measurement!

 

 

5.2 Respiration in Peas Protocol 5.2: Room vs. Cold Temperature

1.  Empty the chamber by PUTTING THE NON-

GERMINATING PEAS BACK ON THE SIDE BENCH, and “clear” it…

2. Rinse and dry chamber

3. Repeat steps 1-7 (Protocol 5.1) using COLD germinating peas

 

 

5.3 Respiration in Crickets Protocol 5.3: Room vs. Cold Temperature

1.  Obtain 5-8 crickets & place in the respiration chamber 2.  Place the CO2 sensor in the chamber 3.  Wait 1 minute → begin collecting data for 5 minutes 4.  Measure & record the weight (g) of the crickets 5.  Place the crickets in the chamber on ice for 5 minutes (or until static) 6.  Follow the instructions on pg. 4

  determine the rate of respiration (slope, m = rate; ppm CO2 min-1)   store the data for comparison with other measurements

7.  Repeat steps 1-6 using COLD crickets 8.  Rinse & dry the respiration chamber when finished

  Use a notebook to “fan” (i.e., clear) the sensor for 1 minute, returning the CO2 level to 300-400 ppm between EACH measurement!

 

 

Do the results support your predictions? Peas   Germinating vs. Non-Germinating

  germinating > non-germinating   WHY?

  Room vs. Cold Temperature   room > cold   WHY?

Germinating

Germinating/COLD

Non-germinating

 

 

Do the results support your predictions?

Crickets   Room vs. Cold Temperature

  room > cold   WHY?

  What about PEAS vs. CRICKETS??   Why is it important to “normalize” by some

biological parameter (= fresh weight) for comparison?

 
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BIOL 320 Final Exam The Written Take Home Final Examination Represents The Final Assessment For This Class. You Will Have 48 Hours From The Time That This Exam Is Made Available To Complete And Submit Your Time Final Exam. Failure To Submit The Timed Fi

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BIOL 320 Final Exam

BIOL 320 Final Exam

The written take home final examination represents the final assessment for this class. You will have 48 hours from the time that this exam is made available to complete and submit your time final exam. Failure to submit the timed final exam document within the time period will result in your exam not being accepted. Use of your, notes, or other resources is strongly discouraged.

1) List and briefly explain the four steps in the scientific method.

2) Which of the following is the correct order of steps in the scientific method?

A

)

experiment, observation, hypothesis, conclusion

B

)

observation, experiment, hypothesis, conclusion

C

)

hypothesis, experiment, observation, conclusion

D

)

observation, hypothesis, experiment, conclusion

Answer:

3) The two most important organelles in forensic DNA analysis are the _________________ and __________________________.

4) The DNA laboratory genotypes three suspects DNA extracted from blood, and DNA extracted from hair roots found at the scene. When the technician draws a conclusion based on the genotyping results, the forensic term for this test or process is called _____________.

5) An experiment is designed to test an hypothesis.

A

)

True

B

)

False

Answer:

6) Due to television shows jurors are expecting to see perfect fingerprints and analyzable DNA on guns and other evidence. The absence of which has led jurors to exonerate otherwise guilty suspects. This is known as the ____ effect.

7) ___________________ is only inherited through the maternal lineage.

8) ______________________ is only inherited through the paternal lineage.

9) ________________________ is inherited through paternal and maternal lineages.

10) A mother is claiming that the only brother of her best friend is the father of her child. The brother is serving at a remote location in the easternmost reaches of Turkey. At the behest of his sister, the brother voluntarily provides DNA for a paternity test. Which of the following are the possible results and conclusions of the tests?

A

)

Since one-half of the alleles from the brother and child matched, then it is highly likely that the father is the brother.

B

)

Since none of the alleles from the brother matched, then it is highly unlikely that the father is the brother.

C

)

Since one-half the alleles did not match, it cannot be ruled out that the father is the brother.

D

)

Since only a few alleles match those of the child, it can be ruled out that the best friend is not the father.

11)

Answer:

11) How many permanent teeth are typically found in a human mouth?

A

)

18

B

)

32

C

)

30

D

)

36

Answer:

12) Measurements made on this bone, provide an accurate method of estimating the stature from skeletal remains

A

)

humerus

B

)

femur

C

)

tibia

D

)

fubula

Answer:

13) Given that the offspring of human parents has the dominant phenotype freckles and cleft chin, the parents gametes could be…

A

)

homozygous dominant for both genes in father; heterozygous dominant for both genes in mother.

B

)

heterozygous dominant for both genes in father and mother

C

)

homozygous dominant for both genes in father, homozygous recessive genes in mother

D

)

homozyogous recessive in Freckle gene and homozygous dominant in cleft gene in mother and father.

Answer

Answer:

14) In a Punnett square, the letters that line the outside of the box represent…

A

)

offspring genotypes

B

)

parental genotypes

C

)

gametes

D

)

offspring phenotypes

Answer:

15) If all thousand offspring of a cross have the genotype Aa, the parents of the cross are most likely…

A

)

AA x aa

B

)

Aa x Aa

C

)

Aa x aa

D

)

AA x Aa

Answer:

16) If the first child of a couple was without dimples, an recessive trait, what is the chance that the second child will be born without dimples?

A) 100%

B) 25%

C) 50%

D) Cannot be determined from the phenotype of the child

Answer:

17) If a gamete with genotype Aa fertilized another gamete with genotype aa, the offspring genotype could be…

A

)

AA

B

)

Aa

C

)

aA

D

)

aa

Answer:

18) What is the phenotype ratio for a cross between Aa and Aa

A

)

1:2:1

B

)

1:3

C

)

1:1

D

)

3:1

 

Answer:

19) What is the genotype ratio of a Aa x Aa cross?

A

)

3:1

B

)

1:2:1

C

)

2:1:1

D

)

1:1:2

Answer:

20) Which of the following parts of a human cell contain information useful to a forensic investigator?

A

)

Nucleus

B

)

Golgi body

C

)

Mitochondria

D

)

Cell membrane

E

)

Nuclear membrane

Answer:

21) In a population of 100 individuals, the genotype frequency of allele 17.1 is .25, then ____ individuals have this allele.

22) DNA is a(n)

A

)

lipid

B

)

protein

C

)

carbohydrate

D

)

polymer

 

Answer:

23) Which of the following base pairs is incorrect?

A

)

G-C

B

)

C-A

C

)

A-T

D

)

T-A

Answer:

24) PCR is a technique that…

A

)

molecularly xeroxes DNA.

B

)

requires primers and enzymes to amplify DNA.

C

)

can amplify many different DNA sequences all at the same time.

D

)

is described by all of the above answers.

Answer:

25) Given the following DNA sequence: 5′-CAGTCA-3′, the complementary strand is_________

26) Which of the following is a use of forensic entomology?

A

)

Obtaining human DNA from the victim’s flesh digested by the insect.

B

)

Determining the cause of death.

C

)

Calculating the PMI.

D

)

Determining the quantity of ingested toxins and drugs from the analysis of insect body parts.

Answer:

27: Which of the following insects are most likely found during the first stages of decomposition?

A

)

Blow Flies

B

)

Dermestid beetles

C

)

Coffin Fly

D

)

Wasps

Answer:

28) The technical term for an insect laying eggs is _______ and the technical term for an insect laying larva is _______.

29) A reddish fluid is found on a floor of a suspect’s house. As a CSI, you desire to make a preliminary determination of the substance. You will likely perform a ____________ test for __________.

30) The element _____ is found in hemoglobin and it is what is detected in several ___________ blood tests

31) Briefly describe the three steps used in PCR?

32) Which of the following is not a characteristic of rigor mortis?

A

)

Upon death, the loss of calcium transport in muscle cells, muscle cells continually contract.

B

)

Rigor Mortis first starts with small muscles in the face and these muscles are the last to relax after several days.

C

)

The rate of rigor mortis is independent upon the victim’s activity and the victim’s age.

D

)

Rigor mortis in and of itself cannot always be a reliable predictor of time since death.

Answer:

33) Which of the following bones are not used for sex estimation in adults:

A

)

pelvis

B

)

tibia

C

)

femur

D

)

cranium

Answer:

34) Which of the following is incorrectly matched?

A

)

oviposits: egg layer

B

)

instars: growth stage

C

)

larvaposit: pupae layer

D

)

nymph: wingless version of an adult insect

Answer:

35) Hemoglobin contains a _____________ group that binds oxygen.

36) True/False: DNA is single stranded and RNA is double stranded.

37) ________________ cells contain a nucleus.

38) Humans have ________ pairs of chromosomes.

39) The expression of a gene is called the gene’s ____________________.

40) A validation procedure must be ___________________, ___________________, and ____________________.

41) The peroxidase activity of heme groups catalyzes the oxidation of ___________________ to ____________________ in the Kastle-Myer presumptive test for blood.

42) A person who has no sperm cells would be classified as being ____________________.

43) The odor in feces is caused by the decomposition products ____________ and _________________.

44) Most animals have three major pairs of salivary glands that differ in the type of secretion they produce called the __________________, _______________________, and ____________________ glands.

45) True/False: Amy2 is the “Salivary Locus” responsible for amylase detected in saliva, sweat, nasal secretions, breast milk and Amy1 is the “Pancreatic Locus” – responsible for amylase detected in semen, blood, urine, feces, and vaginal fluid

46) True/False: Beta Amylase is the type of amylase that is found in plants.

47) True/False: Fingerprints are developed during the early stages of fetal development

48) _______________ fingerprints are composed of the sweat and oils of the body that are transferred from the ridge pattern to some substrate where they persist for some time until found by one of numerous visualizing techniques.

49) The types of manners of death are __________________, ___________________, ___________________, and _____________________.

51) _________________ is the stiffening of the body after death due to the membranes of muscle cells becoming more permeable to calcium ions.

52) Save file with your name in the file extension.

 
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BIOLOGY Lab 12 TEST 3 H BIOLOGY TEXT BASED MULTIPLE CHOICE (ALL CORRECT)

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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which of the following statements about the Domain Bacteria is TRUE?
A) Bacteria are able to increase their genetic variability by reproducing sexually.
B) Bacteria are multicellular microbes.
C) Chloroplasts are found in photosynthetic bacteria.
D) Bacteria lack membrane-bound organelles.
E) Bacterial endospores are fragile structures that are easily destroyed.
2) In bacteria, the small, circular pieces of DNA that are located outside the chromosome are called
A) flagella.
B) bacteriophages.
C) sex pili.
D) plasmids.
E) endospores.
3) The mutations that improve the survival and reproduction of organisms, and thus contribute to
the evolution of species, arise rapidly in prokaryotes due to their
A) rapid rates of cell division.
B) anaerobic metabolism.
C) sexual reproduction.
D) cell wall composition.
E) absence of a nucleus.
4) The use of bacteria to break down pollutants is referred to as
A) nitrogen-fixation.
B) binary fission.
C) biofixation.
D) bioremediation.
E) biosynthesis.
5) Disease-causing bacteria are called
A) Archaea.
B) cyanobacteria.
C) pathogens.
D) protozoa.
E) viroids.
6) Which Protist causes a sexually transmitted disease?
A) Trichomonas
B) Trypanosoma
C) Giardia
D) Plasmodium
E) Pfiesteria
7) Which of the following is FALSE?
A) Viruses are smaller than bacteria.
B) Viruses are not living organisms.
C) Antibiotics cannot prevent or treat viral diseases.
D) The genetic material of viruses is not contained in a nucleus.
E) Viruses are classified in the domain Archaea.
8) A virus basically consists of
A) RNA or DNA and a membrane.
B) enzymes and a protein coat.
C) RNA or DNA and enzymes.
D) RNA or DNA and a protein coat.
E) proteins and a cell membrane.
9) Viroids
A) attack bacteria.
B) are infectious pieces of DNA enclosed in a protein coat.
C) are infectious chains of amino acids.
D) are infectious pieces of RNA.
E) have a plasma membrane.
10) Are viruses alive or are they just biologically active chemicals? Explain your reasoning.

TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.

11) The Kingdom Protista is a group that can best be defined as “any eukaryote that is not a plant, animal, or fungus.” True or False?

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
12) Phytoplankton are very important to the aquatic ecosystems because they
A) produce glucose.
B) produce oxygen.
C) absorb carbon dioxide.
D) All of the above are true.
E) None of the above are true.
13) Individuals of which protist group can grow hundreds of feet long, and almost half a foot per
day?
A) brown algae
B) cyanobacteria
C) slime molds
D) phytoplankton
E) water molds
14) Which of the following is considered to be most closely related to the plants?
A) green algae
B) slime molds
C) diatoms
D) brown algae
E) euglenids
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
15) What would life on Earth be like today, had eukaryotic protists not evolved?
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
16) Fungal hyphae usually are
A) diploid.

B) haploid.

c. triploid
d. n + n
17) The haploid, single-celled product of mitosis is
A) sporophyte
B) gametophyte
C) zygote
D) spore
E) gamete
18) Claviceps purpurea is an organism from phylum ________. It infects rye plants and produces
toxins (including LSD) that can produce convulsions, hallucinations, and death if consumed by
a person.
A) Ascomycota
B) Chytriiomycota
C) Deuteromycota
D) Zygomycota
E) Basidiomycota
19) If a strong fungicide is released and eliminates all the fungi in an ecosystem, which of the
following is likely to happen?
A) an accumulation of dead and discarded plant and animal tissues
B) increased rate of photosynthesis
C) faster breakdown of leaf litter
D) improved soil fertility
E) improved growth of plant species
20) A gametophyte is
A) haploid.
B) diploid.
C) triploid.
D) tetraploid.
E) unable to survive.
21) The first cell after fertilization is the
A) sporophyte.
B) spore.
C) zygote.
D) seed.
E) embryo.
22) Bryophytes
A) are mosses and liverworts.
B) have poorly developed conducting tissues.
C) lack true roots and leaves.
D) A and B
E) all of the above
23) Ginkgoes are classified as a/an
A) bryophyte.

B) gymnosperm.
C) seedless vascular plant.

D) angiosperm.
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
24) Explain the difference between an angiosperm seed and a gymnosperm seed.

25) If motility is considered a characteristic of animals, why are stationary creatures like
sponges and crinoids still considered to be animals?

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
26) Between the organs and the body wall, complex animals have a body cavity called a
A) cnidarian.
B) coelom.
C) mesoderm.
D) thorax.
E) mesoglea.
27) Which of the following characteristics is associated with all animals that are bilaterally
symmetrical at some point in the life cycle?
A) coelom
B) mesoderm
C) cephalization
D) lack of organs
E) gastrovascular cavity
28) Segmentation is important in the evolution of animals because
A) it allows them to be bigger.
B) it increases the number of tissue layers present.
C) it allows for specialization of function.
D) A and B
E) B and C
29) How can flatworms survive without a respiratory system?
A) They are flat, allowing diffusion of gases directly to and from cells.
B) They are small, allowing diffusion of gases directly to and from cells.
C) They are not very metabolically active, and there is no need for a more efficient means of
gas exchange.
D) They have a thin, moist covering that facilitates gas exchange.
E) All of these are true.
30) The taxonomic group containing the largest and most intelligent invertebrates is
A) Aves.
B) Cephalopoda.
C) Uniramia.
D) Gastropoda.
E) Chordata.
31) Which of the following phyla contains animals that reproduce asexually?
A) Platyhelminthes
B) Nematoda
C) Mollusca
D) Cnidaria
E) Annelida
32) The leeches used by doctors to prevent blood clotting and stimulate blood vessel growth in
patients recovering from reconstructive surgery are members of the phylum
A) Cnidaria.
B) Platyhelminthes.
C) Annelida.
D) Nematoda.
E) Arthropoda.
33) All chordates have ________.
A) pharyngeal gill slits
B) bilateral symmetry
C) a fully lined body cavity
D) a dorsal, hollow nerve cord
E) all of the above
34) Which of the following features do humans share with other chordates?
A) Humans have a nerve cord.
B) Humans develop a tail in early development.
C) Humans develop a notochord in early development.
D) Humans develop gill slits in early development.
E) Humans have all of these features.
35) Mammals have all of the following characteristics EXCEPT
A) mammary glands.
B) hair.
C) lungs.
D) a four-chambered heart.
E) All of the above are mammalian characteristics.
36) A fish with fins containing rod-shaped bones surrounded by muscle is a(n)
A) hagfish.
B) lobe-finned fish.
C) lamprey.
D) shark.
E) ray-finned fish.
37) Monotremes differ from other mammals in that they
A) have nipples.
B) have hair.
C) lay eggs.
D) have a four-chambered heart.
E) do not produce milk.
38) ________ are the mammals with the most number of species.
A) Bats
B) Rodents
C) Primates
D) Whales
E) Marsupials
39) After eating at the new Mexican restaurant in town, you develop a mild case of food poisoning. Consequently, you never go back there again to eat. This is an example of
A) trial and error learning.

B) habituation.
C) operant conditioning.

D) insight learning.
40) Innate animal behavior is
A) nonadaptive.
B) learned.
C) not under genetic control.
D) instinctive.
E) both learned and instinctive.
41) A decline in response to a harmless, repeated stimulus is called
A) imprinting.
B) a sensitive period.
C) insight learning.
D) instinctive behavior.
E) habituation.
42) A worm learns to associate a flash of light with an electric shock by
A) operant conditioning.
B) insight learning.
C) imprinting.
D) habituation.
E) trial and error learning.
43) Normal fruit fly larvae move away from their food after eating. However, some larvae that were subjected to X-rays remain near or in their food after eating. There is a consistent difference in the DNA of these two types of larvae. What can be concluded about this behavior?
A) It appears to have a genetic component but is altered by experience.
B) It appears to be entirely learned.
C) It has a clear genetic component.
D) Nothing can be concluded about this behavior from the information provided.
44) What advantage does sound communication have over visual communication?
A) It is more quickly perceived.
B) It uses less energy.
C) It is not as likely to attract predators.
D) It can communicate better the degree of an animal’s readiness for a particular behavior.
E) It can be transmitted over distances even when physical barriers exist.
45) All the following are pheromones EXCEPT
A) sex attractants produced by Japanese beetles.
B) light emitted by fireflies.
C) queen substance produced by honeybees.
D) urine used by wolves to mark territories.
E) trail substances produced by ants.
46) Territoriality
A) results in every individual in a population successfully breeding.
B) decreases aggression within a population.
C) increases the size of a population.
D) All are correct.
E) B and C are correct.
47) Human facial expressions in response to various emotions
A) vary according to race.
B) vary tremendously from culture to culture.
C) are remarkably similar among different cultures.
D) vary according to age.
E) vary according to sex.
48) Studies of identical human twins have shown that
A) they exhibit vastly different behavioral traits if raised in different environments.
B) they do not live as long as fraternal twins live.
C) their genes appear to have a great deal of influence on their behavior.
D) they are no more alike than are fraternal twins.
E) behavior does not depend on the types of genes present.
49) A hungry newborn human infant, touched on the side of her mouth, will turn her head and
attempt to suckle. This example of behavior is
A) not under genetic control.
B) nonadaptive.
C) instinctive.
D) learned.
E) a combination of all the above choices.
50) Behaviors that we call “play”
A) are only observed in humans.

B) never occur in adults.
C) can be dangerous.

 

D) cannot be adaptive.

 
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Assignment For Developmental Biology- Chick Embryology

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Questions

1. Ninety-eight percent of an egg shell is calcite, which is calcium carbonate (CaCO3). Calcium is the major component of bone as well (in the form of calcium phosphate, or apatite). The calcium that goes into the shell comes both from the hen’s diet and from her bones. The average weight of a chicken egg shell is 7.26 grams. A truly remarkable hen can lay an egg a day. In a year, a hen can put into her eggshells over 25 times her own skeletal weight in calcium.

Obviously, this must be replaced. The standard feed given to laying hens is 3 to 4% calcium, and one hen receives about a 100 gm of feed a day. Based on the weight of the shell, is this sufficient to replace the calcium lost in a superhen laying every day? Do the calculations to support your answer.

CaCO3 = 100.9 grams / mole

Atomic weights of molecules from the periodic table.

Ca = 40.08

C = 12.01

O = 16.00

2. Why is the amniote egg considered to be an important evolutionary development?

3. What is the function of the air space in the chick egg?

4. What is the importance of chalazae?

5. Why is initial cleavage of the chick egg meroblastic rather than holoblastic?

6. What is the cavity that underlies the area pellucida? What is its importance relative to the primitive streak?

7. What is the role of the primitive streak and Hensen’s node?

8. Define the term somite.

9. What structure is found between the somites and what is its role?

 
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Bio 144 Case Study

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Escape from Planet Soma

1.How will the non-functional sodium channels affect the signaling capabilities of a neuron? Non-Functioning Na channels affect signals by not providing sodium to enter the cell for depolarization.

2.What type of information do nociceptive neurons carry? They receive painful stimuli because it is a sensory nerve cell.

3.Why would having this mutant gene be so terrible? It would be bad because you wouldn’t know when something is harmful or dangerous

4.What effect will the destruction of myelin have on the signaling capability of a neuron? The signals wouldn’t travel as fast and your reflexes would slow down.

5.Explain why this occurs. This would occur because the myelin sheath insulates the signal and quickens the speed.

6.What will happen to you if you are forced to drink the alien “orange juice”? If forced to drink the alien orange juice it would slow your reflexes and you would feel as if you had multiple sclerosis.

7.How will the signaling of a neuron be affected if the voltage-gated sodium channels open at a more negative membrane potential? Because a voltage-gated sodium channel opens at a specific threshold, if it opens at a more negative membrane potential, the threshold would then be lowered which in then would mean it would be easier to open the channels creating an increased sensitivity to the neuro.

1.Name of your space alter ego.Aicirtap2.How will the non-functional sodium channels affect the signaling capabilities of a neuron? No action potential can be created.

3.What type of information do nociceptive neurons carry? They carry pain signals.

4.Why would having this mutant gene be so terrible? The mutant gene would be able to torment the carrier. The gene could generate unimaginable pain or remove the sense of feeling complete..

5.What effect will the destruction of myelin have on the signaling capability of a neuron? Destruction of myelin will affect the nerve and there will be less conduction of electrical impulses from the brain to other parts of the body and the nerve signal sent to the brain is delayed.

6.Explain why this occurs. These damaged nerve areas form sclerosis which disrupts the signaling capacity of the nerve. This may occur due to genetic defects, infectious agents, autoimmune reactions and trauma

Opening more of Sodium and Potassium Pumps can cause for the neuron to become more excitable because it is reaching resting membrane potential quicker.

14.What will happen to you when sevoflurane reaches the reticular formation neurons that control sleep and consciousness? Sevoflurane causes for a quick recovery from hyperpolarization to resting membrane potential, which means the action potential is met quicker causing you to fall asleep faster.

15.How will increasing extracellular potassium affect the signaling capability of a neuron? The potassium outflow hyperpolarizes the neuron by a normal process, in which the movement of positively charged K+ ions to the outside of the cell moves the interior-anchored voltage potential in the negative direction. The gradient wouldn’t flow as fast with potassium and it would cause slower signals to move between cells.

16.What type of cell normally regulates levels of extracellular potassium in the CNS? Astrocytes regulate levels of extracellular potassium in the central nervous system, which maintain homeostasis of excitatory substances such as potassium

How will increasing extracellular potassium affect the signaling capability of a neuron?-The gradient wouldn’t flow as fast with potassium and it would cause slower signals to move between cells.

What type of cell normally regulates levels of extracellular potassium in the CNS?-Astrocytes What “terror” will this method produce if injected into your brain tissue?-If potassium stays within the cell and travel out of the cell at a slower rate, you would experience a hyperexcitability which will lead to seizures.

How will the excitability of a neuron be affected by sodium channels that open at more positive membranes?

-Less excitability because the threshold is raised.

How does this lead to seizures in the brain? -Seizures can happen when voltage gated channels require a more positive membrane potential to open, because there would be an increase in the degree of depolarization required in order to meet the threshold, and generate an action potential in the neuron. Furthermore, the axon hillock would have a harder time reaching threshold, and the neuron as a whole would operate less. Due to the fact that the neuron as a whole has a hard time firing this can cause seizures in the brain, because there is a loss in balance/homeostasis in the brain.

●How will the non-functional sodium channels affect the signaling capabilities of a neuron?○The non-functional sodium channels affect the signaling capabilities of a neuron by allowing the ions to diffuse through the membrane. This then would take away the concentration gradient, making the neuron no longer able to send a signal.

●What type of information do nociceptive neurons carry?○Nociceptors carry information on pain

.●Why would having this mutant gene be so terrible?○No pain could lead to unobserved injuries, which could be fatal. For example, if you were to place your hand on a hot stove, you could feel the pressure and heat, but not the pain, and could severely burn yourself. While you would be able to see that you burned yourself later, if you were to sustain an internal injury there would be no way of knowing.

●What effect will the destruction of myelin have on the signaling capability of a neuron? ○You wouldn’t have a myelin sheath, so you can’t participate in saltatory conduction. This would drastically slow down signaling.

 
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Bio 144 Case Study

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Escape from Planet Soma

1.How will the non-functional sodium channels affect the signaling capabilities of a neuron? Non-Functioning Na channels affect signals by not providing sodium to enter the cell for depolarization.

2.What type of information do nociceptive neurons carry? They receive painful stimuli because it is a sensory nerve cell.

3.Why would having this mutant gene be so terrible? It would be bad because you wouldn’t know when something is harmful or dangerous

4.What effect will the destruction of myelin have on the signaling capability of a neuron? The signals wouldn’t travel as fast and your reflexes would slow down.

5.Explain why this occurs. This would occur because the myelin sheath insulates the signal and quickens the speed.

6.What will happen to you if you are forced to drink the alien “orange juice”? If forced to drink the alien orange juice it would slow your reflexes and you would feel as if you had multiple sclerosis.

7.How will the signaling of a neuron be affected if the voltage-gated sodium channels open at a more negative membrane potential? Because a voltage-gated sodium channel opens at a specific threshold, if it opens at a more negative membrane potential, the threshold would then be lowered which in then would mean it would be easier to open the channels creating an increased sensitivity to the neuro.

1.Name of your space alter ego.Aicirtap2.How will the non-functional sodium channels affect the signaling capabilities of a neuron? No action potential can be created.

3.What type of information do nociceptive neurons carry? They carry pain signals.

4.Why would having this mutant gene be so terrible? The mutant gene would be able to torment the carrier. The gene could generate unimaginable pain or remove the sense of feeling complete..

5.What effect will the destruction of myelin have on the signaling capability of a neuron? Destruction of myelin will affect the nerve and there will be less conduction of electrical impulses from the brain to other parts of the body and the nerve signal sent to the brain is delayed.

6.Explain why this occurs. These damaged nerve areas form sclerosis which disrupts the signaling capacity of the nerve. This may occur due to genetic defects, infectious agents, autoimmune reactions and trauma

Opening more of Sodium and Potassium Pumps can cause for the neuron to become more excitable because it is reaching resting membrane potential quicker.

14.What will happen to you when sevoflurane reaches the reticular formation neurons that control sleep and consciousness? Sevoflurane causes for a quick recovery from hyperpolarization to resting membrane potential, which means the action potential is met quicker causing you to fall asleep faster.

15.How will increasing extracellular potassium affect the signaling capability of a neuron? The potassium outflow hyperpolarizes the neuron by a normal process, in which the movement of positively charged K+ ions to the outside of the cell moves the interior-anchored voltage potential in the negative direction. The gradient wouldn’t flow as fast with potassium and it would cause slower signals to move between cells.

16.What type of cell normally regulates levels of extracellular potassium in the CNS? Astrocytes regulate levels of extracellular potassium in the central nervous system, which maintain homeostasis of excitatory substances such as potassium

How will increasing extracellular potassium affect the signaling capability of a neuron?-The gradient wouldn’t flow as fast with potassium and it would cause slower signals to move between cells.

What type of cell normally regulates levels of extracellular potassium in the CNS?-Astrocytes What “terror” will this method produce if injected into your brain tissue?-If potassium stays within the cell and travel out of the cell at a slower rate, you would experience a hyperexcitability which will lead to seizures.

How will the excitability of a neuron be affected by sodium channels that open at more positive membranes?

-Less excitability because the threshold is raised.

How does this lead to seizures in the brain? -Seizures can happen when voltage gated channels require a more positive membrane potential to open, because there would be an increase in the degree of depolarization required in order to meet the threshold, and generate an action potential in the neuron. Furthermore, the axon hillock would have a harder time reaching threshold, and the neuron as a whole would operate less. Due to the fact that the neuron as a whole has a hard time firing this can cause seizures in the brain, because there is a loss in balance/homeostasis in the brain.

●How will the non-functional sodium channels affect the signaling capabilities of a neuron?○The non-functional sodium channels affect the signaling capabilities of a neuron by allowing the ions to diffuse through the membrane. This then would take away the concentration gradient, making the neuron no longer able to send a signal.

●What type of information do nociceptive neurons carry?○Nociceptors carry information on pain

.●Why would having this mutant gene be so terrible?○No pain could lead to unobserved injuries, which could be fatal. For example, if you were to place your hand on a hot stove, you could feel the pressure and heat, but not the pain, and could severely burn yourself. While you would be able to see that you burned yourself later, if you were to sustain an internal injury there would be no way of knowing.

●What effect will the destruction of myelin have on the signaling capability of a neuron? ○You wouldn’t have a myelin sheath, so you can’t participate in saltatory conduction. This would drastically slow down signaling.

 
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Human Gergraphy Unit 8 Lab

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 https://www.ted.com/talks/parag_khanna_how_megacities_are_changing_the_map_of_the_world?language=en
  1. How does Khanna feel about the phrase, “geography is destiny”? What is connectography?
  2. What is a megacity cluster? Provide at least one example of a megacity cluster and a resource the cities within that cluster share.
  3. Why do people move to cities? How does this help cities and what do cities ultimately want?
  4. Explain how connectivity has helped improve climate change.
  5. What does Khanna suggest we need to invest in to address the economic disparity within the same megacities and why?
  6. What does Khanna note about Russia regarding its connectivity to the rest of the world? In what ways might this impact Russia’s relationships with other world powers?
  7. According to Khanna, what lines are most important in North America and what does the continent need most?
  8. Explain why Khanna believes connectivity could greatly benefit the Middle East.
  9. Discuss why Khanna believes a major war has not yet broken out in the Far East.

https://www.npr.org/2017/03/13/519954275/the-complications-of-living-in-russia-occupied-south-ossetia

 

  1. In what ways are the lives of people who live in villages like Khurvaleti impacted by frozen conflicts?
  2. After listening to Khanna’s TED talk and the report from South Ossetia, how could connectivity help people caught in frozen conflict?

 

  1. Are we as dependent on the natural world as ancient groups? Why or why not?
  2. What are some of the challenges of feeding the world?
  3. How did agriculture influence the location and structure of early cities?
  4. How did modern transportation change the relationship of cities to food?
  5. What does Steel mean by “sitopia”?
  6. Based on Steel’s discussion, what relationship do you have with the food that you eat? What could you do to have a closer connection to the food that you consume? Write at least two paragraphs discussing this relationship and the changes you could make.
  7. Does the structure of your town or city have any relationship to food? Why or why not? How could a closer connection to food or a “sitopia” be encouraged in your hometown or city? Write at least two paragraphs in response.
 
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Biology Lab Need Done

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image1.emf

image1.emfUMUC Biology 102/103

Lab 7: Ecology of Organisms

INSTRUCTIONS:

· On your own and without assistance, complete this Lab 7 Answer Form electronically and submit it via the Assignments Folder by the date listed on your Course Schedule (under Syllabus).

· To conduct your laboratory exercises, use the Laboratory Manual that is available in the WebTycho classroom (Reserved Reading or provided by your instructor) or at the eScience Labs Student Portal. Laboratory exercises on your CD may not be updated.

· Save your Lab7AnswerForm in the following format: LastName_Lab7 (e.g., Smith_Lab7).

· You should submit your document in a Word (.doc or .docx) or Rich Text Format (.rtf) for best compatibility.

Experiment 1: Effects of pH on Radish Seed Germination

Table 1: Radish Seed Observation and Germination

Solution pH Days 1-2     Day 3     Day 4    
    Observation Seeds Germinated % Observation Seeds Germinated % Observation Seeds Germinated %
Water                    
Vinegar                    
Baking soda                    

Complete the graph. Use the graph provided as your template. You will need to impose figures and shapes over the graph.

image2.emf

00.20.40.60.811.2Category 1Category 2Category 3

image3.emf

00.20.40.60.811.2Category 1Category 2Category 3

 

Questions

1. Was there any noticeable effect on the germination rate of the radish seeds as a result of the pH? Compare and contrast the growth rate for the control with the alkaline and acidic solutions.

2. According to your results would you say that the radish has a broad pH tolerance? Why or why not? Use your data to support your answer.

3. Knowing that acid rain has a pH of 2-3 would you conclude that crop species with a narrow soil pH range are in trouble? Is acid rain a problem for plant species and crops?

TYPE YOUR FULL NAME:

 

� EMBED Excel.Chart.8 \s ���

 

Figure 3: Sprout lengths after 7 days of growth for radish seeds exposed to different pH values.

 

 

_1404629325.xls

Chart1

Category 1 Category 1 Category 1
Category 2 Category 2 Category 2
Category 3 Category 3 Category 3
Series 1
Series 2
Series 3

Sheet1

Series 1 Series 2 Series 3
Category 1
Category 2
Category 3
To resize chart data range, drag lower right corner of range.
 
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Answer The Multiple Choice Questions

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1. A tissue is composed of

 

a- cells.

b- organs.

c- organ systems.

d- cells and organs.

e- cells and organ systems.

 

2. A group of cells performing a similar function is described as

 

a- multicellular.

b- an organism.

c- an organ system.

d- an organ.

e- Tissue.

 

3. Somatic stem cells are found in

 

a- adult tissues.

b- embryonic tissues.

c- umbilical-cord blood.

d- germ tissue.

e- All of the above.

 

4. A group of tissues working together perform the complex functions of

 

a- a tissue.

b- an organ.

c- an organ system.

d- an organism.

e- a bladder.

 

5. Organs are composed of

 

a- one type of cell.

b- one type of tissue.

c- at least two tissues.

d- more than three cell types.

e- None of the above.

 

6. An organ is composed of

 

a- three cell types.

b- at least two specialized tissues.

c- at least 10 specialized cell types.

d- one or more tissue types.

e- groups of cells randomly arranged around a scaffold.

 

 

 

 

7. The bladder is composed of multiple tissues. This organization is beneficial because

 

a- each specialized cell type provides function to the organ.

b- one tissue type would not be functional.

c- having more then one tissue present makes stem-cell harvesting easier.

d- All of the above.

e- None of the above.

 

 

8. The formation of an organ through the use of stem cells differentiated into multiple cell types. However, which of the following presents a hurdle to regenerating a new organ to replace a defective one?

 

a- Many organs contain multiple specialized cell types in an intricate design.

b- Nerve innervation is necessary for the proper function of some organs.

c- Proper blood supply to all the regenerated cells is necessary for the survival of organs.

d- A and C

e- All of the above.

 

9. Which of the following best explains why the rock chimneys of the Lost City host such a variety of unique microbial communities?

 

a- The height of the chimneys creates a gradient of temperatures (hottest at the top and coolest at the bottom) along the chimney; these, in turn, become separate environments and host different communities.

 

b- The height of the chimneys creates a gradient of pH (most acidic at the top and most basic at the bottom) along the chimney; these, in turn, become separate environments and host different communities.

 

c- Although temperatures, pH, and other factors are the same all over each chimney, the chimneys are so big that different communities can occupy different sections of the chimney.

 

d- The Lost City comprises a huge number of rock chimneys, each of which has its own unique environment; this means that each chimney hosts its own unique microbial community.

 

e- None of the above.

 

 

10. Which of the following does NOT refer to a prokaryotic organism?

 

a- smaller than a eukaryotic organism

b- does not have a nucleus

c- has one chromosome

d- reproduces by binary fission

e- has organelles

 

 

 

 

 

 

11. A prokaryote has all of the following structures, EXCEPT

 

a- a cell wall.

b- ribosomes.

c- mitochondria.

d- DNA.

e- Cytoplasm.

 

 

12. Which statement about prokaryotes is FALSE?

 

a- Prokaryotes are diverse.

b- All prokaryotes are bacteria.

c- Prokaryotes are usually single celled.

d- Prokaryotes are found in two domains.

e- Prokaryotes cannot be seen by the naked eye.

 

 

 

 

 

13. The term “extremophiles” refers to

 

a- members of domain Bacteria

b- members of domain Archaea

c- members of domain Eukarya

d- members of both domains Bacteria and Archaea

e- members of both domains Archaea and Eukarya

 

 

14. Bacteria that eat other bacteria are called , while photosynthetic bacteria are called .

 

a- autotrophs; heterotrophs

b- autotrophs; nitrogen fixers

c- autotrophs; phototrophs

d- heterotrophs; autotrophs

e- heterotrophs; phototrophs

 

 

 

 

 

 

 

15. Which does NOT describe members of the domain Archaea?

 

a- They are genetically close to eukaryotes.

b- Some live in extreme environments.

c- They are prokaryotes.

d- They do not have a nucleus.

e- Their cell walls made of peptidoglycan.

 

 

 

16. Which member of the domain Archaea would likely be found in the digestive system of cows?

 

a- Halobacterium

b- Sulpholobus

c- Methanobrevibacter

d- Pyrodicticum

e- Thermoproteus

 

 

17. One of the most ancient forms of metabolism on Earth is _________.

 

a- glucogenesis

b- lipogenesis

c- oxygenesis

d- methanogenesis

e- carbonogenesis

 

18. Which eukaryote evolved first?

 

a- plants

b- fungi

c- protists

d- humans

e- sponges

 

 

19. The tree of life has been rearranged into three domains based on what evidence?

 

a- comparative anatomy

b- DNA similarities

c- homologous structures

d- anatomical evidence

e- fossil evidence

 

 

 

 

 

 

20. The domain Eukarya includes

 

a- plants.

b- plants and animals.

c- plants, animals, and fungi.

d- plants, animals, fungi, and protists.

e- plants, animals, fungi, protists, and archaea.

 

 

 

 

 

21. Which topographical feature affects the climate of an area?

 

a- mountain range

b- plateau

c- coastal location

d- forests

e- volcanoes

 

 

22. The diversity of organisms found in an area is directly related to

 

a- the diversity of temperature.

b- the diversity of elevation.

c- the diversity of rainfall.

d- the diversity of the physical terrain.

e- All of the above.

 

 

23. Which describes plant groups in order of terrestrial adaptations from earliest to the most recent?

 

a- ferns, bryophytes, gymnosperms, and angiosperms

b- bryophytes, gymnosperms, ferns, and angiosperms

c- angiosperms, bryophytes, ferns, and gymnosperms

d- ferns, gymnosperms, bryophytes, and angiosperms

e- bryophytes, ferns, gymnosperms, and angiosperms

 

 

24. Which is the correct evolutionary order of plants, from earliest to most recent, exhibiting the acquisition of terrestrial adaptations?

 

a- sword fern, moss, maple, and pine

b- sword fern, moss, pine, and maple

c- moss, sword fern, pine, and maple

d- moss, sword fern, maple, and pine

e-maple, pine, sword fern, and moss

 

 

25. The sunny, south-facing slopes of the Olympic Mountains are relatively dry. In the forests there, you would expect to find

 

a- relatively few bryophytes, but numerous ferns, gymnosperms, and angiosperms.

b- fewer bryophytes and ferns than gymnosperms and angiosperms.

c- fewer ferns than bryophytes, gymnosperms, and angiosperms.

d- fewer gymnosperms than bryophytes, ferns, and angiosperms.

e- fewer angiosperms than bryophytes, ferns, and gymnosperms.

 
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Lab 6 Senses

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Lab 6 Senses

Materials

Organisms

Fresh carrot

Fresh apple (22 cm x 28 cm x 8 cm)

Pictures from textbook

Human eye

Human ear

Human skin

Chemicals

5% sucrose (about 1 tablespoon of sugar in one cup of water)

10 % NaCI (sodium chloride) (about 1 tablespoon of table salt in 1/2 cup of water)

0.5% acetic acid (household vinegar is OK)

Hardware

Construction paper for afterimage cards

Penlight (or desk lamp)

Paper tube (3 cm x 45 cm)

Meter stick (yardstick will work)

Tuning fork (or two spoons)

Scissors

Millimeter ruler

3 medium size bowls

Ice bath

Cotton swabs

Learning Objectives

Students should be able to

1. identify the parts of the eye, ear, and skin and state a function for each part;

2. describe the experiments that make up this laboratory session and explain their significance.

Introduction

Sense organs contain receptors which are sensitive to a particular type of environmental stimuli. After receptors receive stimuli, they generate nerve impulses. Eventually these nerve impulses reach the brain, where the phenomenon sensation occurs. The brain interprets the world around us and depends on the receptors for the proper input. Because the sense organs have a limited ability to respond to the environment, we can be fooled sometimes.

 

 

Human Eye

The human eye is a special sense organ because it is a large, complex organ containing many receptors. The receptors in the eye are either rods or cones, both of which are photoreceptors. The parts of the eye are depicted in Figure 18.6 on page 345 of your textbook.

With the help of figure 18.6, identify the following structures and give a function for each structure in the space provided.

Sclera

Cornea

Choroid

Retina

Fovea centralis

Lens

Ciliary body

Iris

Pupil

Optic nerve

Which of the structures listed aid in refracting and focusing light rays?

Which of these structures contain( s) the receptors for sight?

What are the receptors for sight?

Which of the structures listed transmit(s) nerve impulses to the brain?

Afterimages

We see images because the rods and cones are generating nerve impulses for transmission to the brain. Occasionally the brain retains an image even after the impulses have stopped. These images are called afterimages. A positive afterimage is one in which the bright parts of the object remain bright and the dark parts remain dark. In a negative afterimage the bright parts of the object appear dark and the dark parts appear bright.

Experimental Procedure:

Center a red card on a black sheet of paper and stare intently at the card. After about thirty seconds or longer and without shifting the eyes, place a white sheet of paper over the red card. Describe in the following table the color of the image that “appears” on the white paper.

Repeat by placing green, blue, and yellow cards on the black paper and later covering with a white sheet.

Card Color                 Color of Afterimage

Red

Blue

Yellow

Green

Blind Spot

The blind spot occurs where the optic nerves exit the retina. No vision is possible because of the absence of rods and cones at this location.

Experimental Procedure:

This procedure requires a laboratory partner. Enter the data for your own eyes in your laboratory report.

1. Determine the blind spot of the left eye.In figure A, you will see a small cross and a circle a few inches apart from one another. Hold the figure 30 cm away from your eyes. Tip the paper so both the cross and the circle are on the same level. If you wear glasses, keep them on.

Close your right eye only. Stare at the cross only with your left eye. You also should be able to see the circle in the same field of vision.

Slowly move the paper toward you until the circle disappears. At this point, the circle is being focused on the blind spot of your left eye.

Measure the distance from your eye to the paper with a meterstick when the circle first disappears.What is the distance in cm?____ (left eye).

Keep moving the paper close to your eyes until the circle reappears. (If you use a yardstick, measure in inches and multiply by 2.54 to convert to cm.)

FigureA. To test for the blind spot, use these symbols and the directions provided below. You might want to redraw these marks on a blank piece of paper to make this easier. Make the marks about the same distance apart as your eyes are.

…………+

2. Determine the blind spot of the righteye.To determine the blind spot of your right eye, repeat the procedure just describedbut with the following modifications.

Close only your left eye and look at the circle with your right eye. Move the paper close to your eyes until the cross disappears. At this point the cross is being focused on the blind spot of your right eye.Measure the distance from the paper to your right eye when the cross first disappears.

What is the distance in cm? (right eye).

Is the measured distance the same for both eyes?

Accommodation of the Eye

The eye accommodates for focus at different distances by changing the shape of the crystalline lens. The lens is controlled by the ciliary muscles (within ciliary body) attached to the lens. When you look at a distant object, the lens is in a flattened state.

When you look at a closer object, the lens becomes more rounded. The eye is said to accommodate for distance. The elasticity of the lens determines how well the eye can accommodate.

Experimental Procedure:

This procedure requires a laboratory partner. Enter the data for your own eyes and in your laboratory report.

1. Accommodation of your right eye.

Hold a pencil by the eraser in your right hand. Close your left eye.

Move the pencil from arm’s length toward your right eye. Focus on the point of the pencil.

Move the pencil until the point is out of focus.

Measure the distance between the pencil and your right eye. At what distance can your right eye no longer accommodate for distance? (report in cm.)

If you wear glasses, repeat this experiment without your glasses. (Do not take out contact lens if you have them)

What is the accommodation distance of the right eye without glasses? (report in cm.)

2. Accommodation of your left eye.

Repeat the procedure described. Close your right eye and look at the pencil point with your left eye. What is the accommodation distance of your left eye? cm.

If you wear glasses, repeat the same experiment without your glasses. What is the accommodation distance of the left eye without glasses? cm.

3. The “younger” lens can easily accommodate for closer distances. The more elastic the lens, the “younger” the eye.The nearest point at which the pencil point can be seen clearly is called the near point.

Age (years)     10  20  30  40  50   60

Near point (cm) 9   10 13   18  50  83

How “old” is your right eye? How “old” is your left eye?

How “old” is your right eye without glasses ?How “old” is your left eye without glasses?

Pupillary Reflexes

The pupil is really a hole in the iris, a donut-shaped muscle. When certain fibers of the iris contract, the pupil dilates; when other fibers contract, the pupil constricts. Normally, the pupils dilate in dim light and constrict in bright light.

Experimental Procedure:

This test must be conducted in a dimly lit area and requires a laboratory partner

1. Pupillary reflex in both eyes. The experimenter faces the subject and looks at the pupils. The subject closes his or her eyes and covers them with the hands for approximately two minutes. The subject opens his or her eyes, and the experimenter shines a penlight into one eye, then the other, and back again. What happens to the pupils?

2. Pupillary reflex in one eye. The subject holds the edge of an index card along the nose to divide the field of vision. The experimenter tests thepupillary reflex of one eye using the penlight as just described.

Does a comparable reflex occur in the non-illuminated eye?

Do pupils adjust independently or together?

Superimposition

Both eyes view the same field, but because of the optic chiasma (fig. 18.10 page 348 in textbook), both eyes send information about the right field to the left side of the brain, and vice versa. If each eye by chance views a different field, the information is mixed in the brain.

Make a paper tube about 1.5 feet long (or use the cardboard tube from a roll of paper towels). Keeping both eyes open, hold the tube up to one eye and look at some distant object through the tube, then bring the free hand up in front of the other eye and move this hand back and forth along the tube. A hole will appear in your hand.

The Human Ear

The human ear is a special sense organ because it is a large, complex organ containing many receptors. In the ear, the organ of Corti, in the cochlea, contains hair cells which allow us to hear. The semicircular canals and the utricle and saccule help maintain balance. The parts of the ear are listed in Table 18.3 (page 352 in your textbook) and depicted in Figure 18.11 and Fig 18.12 (pages 349+350 in your textbook).

With the help of figure 18.11, study the ear and identify the outer, middle, and inner ear and their parts listed next. With the help of table 18.3, give a function for each part named.

1. Outer ear

Pinna

Auditory canal

2. Middle ear

Tympanic membrane (eardrum)

Ossicles (hammer, anvil, stirrup)

3. Inner ear

Cochlea

Semicircular canals

Auditory nerve

Which of the preceding structures transmits sound waves?

Which contains the receptors for hearing?

What are the receptors of hearing?

Which of the preceding transmits a nerve impulse to the brain?

The eustachian tube runs between the middle ear and the throat. It helps equalize the external air pressure with that in the middle ear. Is theeustachian tube indicated in the figure?

Direction of Sound

Humans locate the direction of sound according to how fast it is detected by either or both ears.

Experimental Procedure:

You will need a laboratory partner to perform this procedure. Enter the data for your ears in your laboratory report.

The seated subject closes both eyes. Strike two spoons together or strike a tuning fork and ask the subject to give the exact location of the sound in relation to his or her head.

What does the subject report when the sound is:

directly below and behind the head?

directlybehind the head?

directlyabove the head?

directlyin front of the face?

tothe sides of the head?

Explain why the subject incorrectly identified the location of some of these.

Skin Receptors in Humans

The skin receptors in humans concern sensations such as touch, pain, temperature, and pressure. There are individual receptors for each of these various sensations.

Human Skin

With the help of figure 11.8 (page 199 in your textbook), study the image of the skin and identify these areas or structures. State the location of each.

1. Subcutaneous layer

2. Adipose tissue

3. Dermis

4. Epidermis

5. Hair follicle and hair

6. Sebaceous gland

7. Sweat gland

8. Receptors

Experimental Procedure:

You will need a laboratory partner to perform the following procedures.

Touch

The subject is seated with his or her eyes closed. In the following manner, test the subject’s ability to discriminate two pointsof a pair of scissors in the skin areas listed next. Hold the points of a pair of fine scissors on the given skin area, with eitherone or both of the scissor points gently touching the subject. The subject should respond whether he or she feels one or twotouch sensations.

Record the shortest distance for a two-point discrimination.

1. Forearm

2. Back of the neck

3. Index Finger

4. Back of the Hand

Which of these areas contains the largest number of receptors for touch?

How do you know?

Heat and Cold

Fill three medium size bowls as follows: (1) ice water; (2) tap water at room temperature; and (3) warm water

Place your left hand in the first beaker and your right hand in the third beaker. Keep both hands immersed for at least thirty seconds.

Place both hands in the second beaker. Record the sensation in the right and left hands.

Right hand:

Left hand:

Explain these results:

 

 

Chemoreceptors

The taste receptors located in the mouth and the smell receptors located in the nasal cavities are the chemoreceptors that respond to molecules in the air and water.

Experimental Procedure:

You will need a laboratory partner to perform the following procedures.

The experimenter should be sure to use a clean cotton swab each time. The subject should be sure to rinse the mouth between applications.

The experimenter applies each of the following solutions to the tip, sides, and back of the tongue and records in the table whether or not the subject can taste them. See the Materials section at the top to find the recipes for these solutions.

Solutions: 5% sucrose (sweet)

10% NaCI (salty)

Household vinegar (sour)

Taste Tongue tip Tongue sides Tongue back

Sweet

Salty

Sour

Figure18.4 (page 344 in your textbook) illustrates the human tongue. It is believed we have four taste sensations -sweet, sour, salty, and bitter – and each is located on the tongue in a different position.

See if you can identify where these taste sensations appear on your tongue. Where did you find them?

Smell and Taste

This experiment requires that you have a partner. One person is the timekeeper and the experimenter, and the other is the subject.The subject eats a piece of carrot and a piece of apple before the experiment begins. Use the hardest apple and the softest carrot available. You will need two small pieces of peeled apple and two small pieces of peeled carrot for the experiment.The four pieces should be about the same size and shape. During the experiment the subject should not allow the piece of carrot or apple to touch the roof of the mouth.

1. The subject shuts his or her eyes and holds his or her nostrils closed. When ready the experimenter places a piece of either carrot or apple on the subject’s tongue. The subject reports whether the piece is carrot or and the time taken for response is noted. Do not tell the subject whether he or she is right or wrong.

After the response, the experimenter removes the pieceofcarrot or apple and disposes of it. Repeat twice with each material.

Fill in the table, recording the actual substance, the subject’s response, and the length of time taken for the response.

Taste and Smell Experiment

Substance Subject’s response Time taken

1.

2.

3.

4.

2. The subject shuts his or her eyes and keeps his or her nostrils open. Repeat the preceding procedure but now, the subject can smell the piece of food before it is placed on the tongue. Record the results as before in the next table.

Substance Subject’s response Time taken

1.

2.

3.

4.

Conclusion

Did the subject respond more accurately and/or more quickly during the second test?

If so, how do you account for this?

Laboratory Review

1. Name the portion of the eye that is sensitive to light.

2. In the eye, focusing is done primarily by the ____________?

3. Which part of the eye is responsible for rounding the lens?

4. Are negative afterimages the same as or different from the original color?

5. Do the pupils become larger or smaller in the dark?

6. What part of the ear contains the sense receptors for hearing?

7. What are the three little bones in the middle ear collectively called?

8. Subjects had the most difficulty detecting the location of a sound made where in relation to their heads?

9. What is the inner layer of skin called?

10. Both taste and smell are produced by _________________________?

 

 
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