Topic 2

Question 1

What is Parthenogenesis? And what are the two types of parthenogenesis

Answer 1

The development of an egg with no paternal contribution - female clonal reporduction; “virgin birth”

1. Obligate parthenogenesis
2. Cyclical parthenogenesis

Question 2

Obligate parthenogenesis

Answer 2

only females exist (in species), eggs never develop into males and there is never sexual reproduction

Question 3

Cyclical parthenogenesis

Answer 3

Males develop from eggs at some point, resulting in sexual reproduction, and this reporduction produces an all female population that reproduces clonally

Question 4

Two hypothesis describing what is a species

Answer 4

1.Morphological species concept:
Indiv are considered to belong to the same species if they agree morphologically with the “type” of the specis

2. Biological Species concept:
   species are groups of interbreeding natural populations that are reproductively isolated from other such groups
3. Phylogenetic species concept
   not covered in this class

Question 5

Morphological species concept

Answer 5

Indiv are considered to belong to the same species if they agree morphologically with the “type” of the specis

Question 6

Biological Species concept

Answer 6

species are groups of interbreeding natural populations that are reproductively isolated from other such groups (only works for sexually reprod. pop’n, not for asexual)

Question 7

7 things that cause H-W disequilibrium

Answer 7

• Natural selection: heterozygote excess/deficit
• Inbreeding: heterozygote deficits
• outbreeding: heterozygote excess
• assortative mating: heterozygote excesses or deficits
• asexual reproduction: heterozygote excesses or deficits
• cryptic species: heterozygote deficits
• gene flow ad migration: heterozygote excesses or deficits

Question 8

important exception to H-W principle

Answer 8

sex determination: e.g. in humans, males have only 1 X chromosome vs females have 2 (Y chromosome only carries few genes)

Question 9

genes which are found on X chromosome

Answer 9

X-linked genes

Question 10

homogametic sex

Answer 10

sex which produces two of the same gametes (e.g. females produces 2 X in humans)

Question 11

heterogametic sex

Answer 11

sex which produces two different gametes (eg. male produces X and Y gametes)

Note: in some groups e.g. birds, moths and butterflies, females are heterogametic (W and X)

Question 12

homogametic sex

Answer 12

sex which produces two of the same gametes (e.g. females produces 2 X in humans)

Question 13

heterogametic sex

Answer 13

sex which produces two different gametes (eg. male produces X and Y gametes)