Biology Ch. 5 and 6

Question 1

Capacitation

Answer 1

Final maturation step of sperm once inside female reproductive tract.
Enzymes in the uterus and fallopian tubes remove the glycoprotein coat of sperm, revealing the acrosome and making the sperm hyperactive.

Question 2

Fertilization Process

Answer 2

Sperm pushes through corona radiata.
ZP receptors determine if it is same species.
ZP3 triggers acrosome reaction, which releases acrosin to break through the zona pellucida.
Sperm head enters perivitelline space and fuses with the plasma membrane.

Question 3

Fast and Slow Blocks to Polyspermy

Answer 3

Fast: Na channels open immediately after fusion, which causes depolarization of the egg membrane and prevents entry of more sperm for short period of time.
Slow: aka cortical reaction. Depolarization causes Ca2+ release from ER, which triggers exocytosis of cortical granules. This causes swelling of the perivitelline space and inactivates ZP receptors.

After the slow block, a second meiotic division of the egg is completed.

Question 4

Phases of Arrest in Oogenesis

Answer 4

Primary oocytes begin meiosis and are arrested at prophase 1 during development.
During puberty, hormones cause one primary oocyte at a time to continue meiosis and become a secondary oocyte.
The secondary oocyte is arrested in metaphase 2.
If the secondary oocyte is fertilized, it will continue the rest of meiosis.

Question 5

Cleavage

Answer 5

Rapid cell division without growth (making slices in a pizza).
Cleaved cells are called blastomeres.

Question 6

Types of cleavage in Protostomes and Deuterostomes

Answer 6

P: determinant, spiral.
D: indeterminant, radial.

Question 7

Morula
Blastula
Gastrula

Answer 7

M: 16-32 blastomeres; becomes blastula thru blastulation.
B: hollow ball of cells; becomes gastrula through gastrulation.
G: invagination called blastopore begins to form; will either become mouth or anus.

Question 8

Archenteron

Answer 8

Space caused by the blastopore in gastrula

Question 9

Gray Crescent

Answer 9

In amphibians.
After fertilization, cytoplasm rotates 30 degrees to form gray crescent.
Cells in the grey crescent are vital in development and can develop into an entire organism.

Question 10

Neurulation

Answer 10

Notochord stimulates overlying ectoderm to thicken, forming the neural plate.
The neural plate folds inward and pinches off to form the neural tube, which becomes the brain and spinal cord.

Question 11

Ectoderm Derivatives

Answer 11

Epidermis
Adrenal Medulla
Jaw and teeth
Sensory system
Nervous system
Skull bones, muscles, and connective tissue.

Question 12

Endoderm Derivatives

Answer 12

Epithelial lining of GI, respiratory, excretory, and reproductive tracts.
Thyroid
Parathyroid
Thymus
Liver
Pancreas

Question 13

Mesoderm Derivatives

Answer 13

Bones, cartilage, muscles, connective tissue.
Adrenal cortex
urogenital organs, kidneys, spleen
heart, circulatory, lymphatic systems
Notochord

Question 14

Simple vs. Complex Reflexes

Answer 14

S: 2 nerves, controlled at spinal cord.
C: 3 nerves (interneuron) controlled at brain stem/cerebrum.

Question 15

Imprinting

Answer 15

Specific type of irreversible learning in young animals if the appropriate stimulus is experienced during critical/sensitive period.
Ex: baby geese recognizing something that moves as their mother.

Question 16

Fixed Action Patterns

Answer 16

Sequence of instinctive behavior initiated by sign stimuli.
The action will usually be completed even if original stimulus is removed.

Question 17

Insight

Answer 17

Behavior with positive outcome performed in response to novel situation never encountered before.

Question 18

Operant Conditioning

Answer 18

Connection of own behavior to reward or punishment.

Positive: giving
Negative: taking away

Question 19

Habituation vs. Sensitization

Answer 19

H: Decrease in response to stimulus after repeated exposure without consequences.

S: increased response to stimulus; opposite of habituation.

Question 20

Mating Systems:
Semelparity
Iteroparity

Answer 20

S: one reproductive event during life; lots of offspring with low survival rate.

I: repeated reproduction; few but large offspring with high survival rate.

Question 21

Survivorship Curves

Answer 21

Type I: most survive to middle age and die quicker after that; K selected (humans).
Type II: length of survivorship is random (birds).
Type III: most die young, and few survive to reproductive age and beyond; R selected(plants).

Question 22

Biomagnification

Answer 22

as one organism eats another, toxins become more concentrated at higher trophic levels.

Question 23

Eutrophication

Answer 23

Process where water becomes enriched with excess nutrients and biomass increases.
Leads to water being depleted of oxygen and death of aquatic organisms.

Question 24

Primary vs. Secondary Succession

Answer 24

1: occurs on substrates that never previously supported living things.
2: occurs where communities were entirely/partially destroyed by a damaging event.

Question 25

Fundamental Niche vs. Realized Niche

Answer 25

F: niche that an organism occupies where there are no competing species present.
R: smaller subset of the niche that species occupy when competition is present.

Question 26

Fitness

Answer 26

Ability of an offspring to survive and produce fertile offspring.

Question 27

Stabilizing Selection
Directional Selection
Disruptive Selection

Answer 27

S: bell curve favors an intermediate.
Dir: favoring of traits at one extreme, while traits at the other extreme are selected against.
Dis: traits at either extreme are favored while moderate/common traits are selected against.

Question 28

Founder Effect vs. Bottleneck Effect

Answer 28

F: small group of individuals migrate to a new location; small gene pool; after several generations, the genetic makeup will be different than original population.

B: population undergoes dramatic decrease in size due to natural catastrophes; gene pool is smaller and subject to genetic drift.

Question 29

Gene Flow vs. Genetic Drift

Answer 29

GF: introduction and removal of alleles from the population when individuals leave or enter the population.

GD: random increase and decrease of an allele by chance; larger effect on small populations.

Question 30

Requirements for Hardy-Weinberg Equilibrium

Answer 30

1. No mutations
2. No natural selection
3. No gene flow
4. Large population
5. Random mating

Question 31

Hardy-Weinberg Equation

Answer 31

p^2 + 2pq + q^2 = 1

p^2: frequency of homozygous dominant
2pq: frequency of heterozygous
q^2: frequency of homozygous recessive

p + q = 1
p: freq of domininat
q: freq of recessive.

Question 32

Sources of Genetic Variation

Answer 32

Mutation
Sexual Reproduction
Balanced polymorphism
Diploidy

Question 33

Homologous vs. Analogous Structures

Answer 33

H: body parts that resemble one another between different species descended from a common ancestor.
A: body parts that resemble one another between different species that evolved independently. ( bat and bee wings).

Question 34

Divergent Evolution

Answer 34

formation of two or more species that descend from a common ancestry and become increasingly different over time (results of speciation).

Question 35

Convergent Evolution

Answer 35

Two unrelated species independently evolving similar traits as a result of having to adapt to similar environments (analogous traits)

Question 36

Parallel Evolution vs. Coevolution

Answer 36

P: two related species develop similar adaptations or traits after their divergence from a common ancestor.
C: two or more species having a close ecological relationship evolve together in response to new adaptations that appear in another species (predator/prey).

Question 37

Allopatric vs. Sympatric Speciation

Answer 37

A: population is divided by a geographic barrier.
S: occurs without the presence of a geographic barrier (polyploidy).

Question 38

Prezygotic vs. Postzygotic Reproductive Isolation

Answer 38

Pre: happens before zygote is formed.
Post: happens after zygote is formed.

Question 39

Mullerian vs. Batesian Mimicry

Answer 39

M: two or more harmful species that are not closely related but share common predators mimic each other’s warning signals.
B: harmless species has evolved to imitate the warning signals of harmful species directed at a common predator.