A. Introduction

Question 1

In which way of vegetative reproduction does the size of the original cell not get reduced?

Answer 1

Budding (ex. yeast)

Question 2

What are three strategies for vegetative reproduction?

Answer 2

1) Budding (yeast)
2) Fission (bacteria)
3) Fragmentation (sea star)

Question 3

What are the only ways of “asexual reproduction” in mammals?

Answer 3

1) Polyembryony (identical twins/triplets in humans, identical octuplets in nine-banded armadillo)
2) Parthenogenesis

Question 4

What is parthenogenesis?

Answer 4

Reproduction using eggs, but without sex (the eggs are never fertilized by a male)

Question 5

What are the two types of parthenogenesis?

Answer 5

1) Apomixis

2) Automixis

Question 6

What happens in apomixis?

Answer 6

The female does not undergo meiosis and only goes through mitosis so the eggs are exactly the same as the female and end up AB.

Question 7

What happens in automixis?

Answer 7

The female undergoes meiosis initially but then restores diploidy by combining two cells, so they can be AA or AB.

Question 8

What are the three forms of “pseudoparthenogenesis”?

Answer 8

1) Androgenesis
2) Gynogenesis
3) Hybridogenesis

Question 9

What is androgenesis?

Answer 9

The female produces eggs but when the sperm fertilize, only the male genetic material is used.

Question 10

What is gynogenesis?

Answer 10

Female produces diploid cells with genetic material and only need male sperm to activate and do not get to add genetic material.

Question 11

What is hybridogenesis?

Answer 11

The female passes on part of her genetic makeup which is then fertilized by a complete different species.

Question 12

What are three asexual reproductive benefits for SPECIES success?

Answer 12

1) Survival
2) Compete
3) Expand

Question 13

What are three asexual reproductive benefits for INDIVIDUAL success?

Answer 13

1) Survival
2) Compete
3) Biological immortality

Question 14

What are four costs of sex?

Answer 14

1) Only half the population can give birth - slow growth. Half the offspring are male - can’t give birth.
2) Males consume resources year-round. Less females can be supported.
3) Your genes are diluted in the next generation. Parents don’t achieve total genetic immortality.
4) Increased costs with finding a mate, courtship, and mating. Increased risks of predation and increased energy requirements.

Question 15

What are four barriers to parthenogenesis?

Answer 15

1) Oocyte activation.
2) Restore diploidy.
3) Centromere source.
4) Mammalian genome is imprinted.

Question 16

What are the two main theories for the importance of sex?

Answer 16

1) Muller’s Ratchet.

2) The Red Queen.

Question 17

Explain the “Muller’s Ratchet” theory.

Answer 17

Most genetic mutations are deleterious. Accumulate over time if not repaired. Organism “ratchets forward” with decreasing fitness over generations.

Question 18

Explain the “Red Queen” theory.

Answer 18

Our biological enemies are constantly evolving to overcome our defenses. Our defense against this is to be as genetically variable as possible so that some of us are resistant to the mechanisms our enemies evolve.

Question 19

If two sexes are good, why not three, four, or more?

Answer 19

The species’ appear unstable and tend to revert to two or one sex systems. This is seen in higher fungi and lower eukaryotes.

Question 20

What were three conditions that determined what sex you were (long, long, long time ago)?

Answer 20

1) Conditions in uterus (hot/dry = male; cold/damp = female).
2) Side of uterus semen enters (right side = male; left side = female).
3) Testicle of origin (semen from right testis = male; semen from left testis = female).

Question 21

What are the eight types/levels of sex?

Answer 21

1) Genetic (sex-specific chromosomal pattern).
2) Gonadal (ovary vs testis).
3) Germ cell (egg vs sperm).
4) Hormonal (estrogen vs androgen).
5) Phenotypic (internal and external genitalia, secondary sex characteristics).
6) Somatic (brain).
7) Behavioral.
8) Legal.

Question 22

What are the three steps in mammalian sex determination?

Answer 22

1) Genetic sex (X-oocyte + X- or Y-bearing sperm).
2) Sex determination (Y chromosome either causes testis or ovary formation).
3) Sex differentiation (phenotype from specific hormone secretions from either testis or ovary).