Cycle 7 - All about sex

Question 1

Non-random mating

Answer 1

Individuals select mates based on phenotypes

Question 2

Sexual Dimorphism

Answer 2

Sexes look different (male and female ducks)

Question 3

Sexual monomorphism

Answer 3

Sexes look the same

Question 4

Intersexual selection

Answer 4

One sexes chooses based on displays and physical traits. The sex that invests the most parental care is typically the chooser.

Question 5

Intrasexual Selection

Answer 5

Individuals of the same sex compete for mates.

Question 6

Direct Benefits of Parental Investment

Answer 6

Food, territory, protection for offspring, attractive individuals are good parents

Question 7

Indirect Benefits of Parental Investment

Answer 7

Attractive individuals have good alleles = better survival of offspring (ex. stronger immunity)

Question 8

Sperm competition

Answer 8

Swimming speed - fastest sperm to get to the egg
Scrapers - scrape out sperm deposited by other males
Mating plugs - after mating, leave a plug to prevent other males from mating

Question 9

Which sex usually has higher potential fitness

Answer 9

Males

Question 10

Selective forces on males

Answer 10

reproduction is mainly limited by access to females

Question 11

Selective forces on females

Answer 11

Having limited gametes, time sped growing offspring, must choose mate wisely to maximize quality of offspring.
Individual fitness is often closer to the mean.

Question 12

Which sex has higher average fitness

Answer 12

average fitness is similar for both sexes

Question 13

Conjugation

Answer 13

transfer of plasmids in bacteria during “sex”

Question 14

Transformation

Answer 14

DNA from the environment in bacteria during “sex”

Question 15

Transduction

Answer 15

DNA moved around by viruses during “sex”

Question 16

Obligately asexual

Answer 16

only reproduces asexually

Question 17

facultatively sexual

Answer 17

can reproduce both sexually or asexually

Question 18

obligately sexual

Answer 18

can reproduce sexually

Question 19

Parthenogenesis (exception to obligately sexual)

Answer 19

Females produce offspring without sperm fertilizing their eggs. Offspring develop from unfertilized diploid eggs. Egg remains diploid during gamete formation (clones, no meiosis) or DNA in haploid egg replicates = haploid to diploid (meiosis, not clones)

Question 20

Asexual reproduction in unicellular organisms

Answer 20

Divide to reproduce (bacteria, archaea by binary fission), genetically identical offspring - clones

Question 21

Asexual reproduction in plants results in

Answer 21

genetically identical individuals (clones)

Question 22

Sexual reproduction in animals and plants

Answer 22

Involve two sexes which have two gametes which then fuse together.

Question 23

Sexual reproduction in fungi and protists

Answer 23

Fusion of cells or exchange of nuclei between different mating types, then nuclei fuse.

Question 24

Dioecious

Answer 24

each individual is either male or female

Question 25

Monoecious / hermaphrodites

Answer 25

Individuals have both male and female functions/structures

Question 26

Simultaneous monecy

Answer 26

Both male and female at the same time

Question 27

Sequential monecy

Answer 27

Born one sex but develop in another at a certain time

Question 28

Benefits of reproducing sexually

Answer 28

generates variation = greater adaptability
sexual reproduction can make better combination of alleles (long-term)
sexual reproduction more efficiently removes bad combination of alleles
generates genotypes for higher fitness more quickly

Question 29

Costs of reproducing sexually

Answer 29

risky - time consuming, takes energy and resources, exposure to predation and stds.
costly - For every generation, sexual individuals pass on 2x less of their genetic material unlike asexual individuals who pass o ball of their genetic info
inefficient - only females grow offspring, asexual populations grow faster

Question 30

Lottery principle

Answer 30

diversifying variety of offspring in unstable environments increases chances of some surviving

Question 31

Clonal interference

Answer 31

prevents combinations of “good” mutations

Question 32

Size advantage model

Answer 32

The point of intersection is when the sex changes. The greater the y axis, the greater the reproductive success.

Question 33

Protandry

Answer 33

when an organism goes from male to female

Question 34

Protogyny

Answer 34

when an organism goes from female to male