Sex & Evolution

Question 1

what is present or true of asexual reproduction

Answer 1

a genetically identical offspring

Question 2

a pea hen (female peacock) is described as ___ when mating

Answer 2

choosey

Question 3

definition of intrasexual

Answer 3

male to male competition

Question 4

what is batsman’s principal

Answer 4

female choosiness

Question 5

natural selection in birds

Answer 5

beak size and shape

Question 6

polyandry

Answer 6

more than one husband

Question 7

what is an example of bateman principle

Answer 7

ancestral women typically could now have dramatically increased their reproductive output but adding more sex partners

Question 8

when given a choice, as opposed to a stable internal predisposition, a female animal engages in sexual behaviour with another female. this is an example of an individuals:

Answer 8

sexual preference

Question 9

name some environmental cues for sex determination in animals

Answer 9

temperature (crocodiles and turtles) -

available nutrients, water availability, photoperiod it time of year, competitive stress, pheromones from conspecifics

Question 10

what aminals do not use environmental sex determination?

Answer 10

mammals and birds

Question 11

what is sexual reproduction?

Answer 11

process of developing a genetically unique individual

Question 12

what is asexual reproduction

Answer 12

a single parent generates offspring that are genetically identical

Question 13

asexual reproduction is characterized by the absence of three sexual reproductive factors:

Answer 13

meiosis, reduction in ploidy (pairing of chromosomes or number of chromosomes) and the fusion of gametes

Question 14

types of asexual reproduction: (3)

Answer 14

budding (portion of the parent buds out and goes off on its own and develops into a fully functioning organism fully attached to the parent and then breaks off
— common in vertebrates and small organisms in the sea
fragmentation (parent individual breaks off a piece of itself and then later develops into its own individual
—starfish, flatworm
parthenogenesis (develop a gamete without fertilization
— virgin births

Question 15

how is sex expensive?

Answer 15

the cost of meiosis to generate a haploid gamete or cells (reproducing individuals that cannot reproduce on their own

the cost of finding a mate (sexual displays and rituals are energy, time and resource expensive)

Question 16

what is the advantage to reproducing sexually?

Answer 16

more diverse gene pool protection, resource gathering, social organization to benefit from groups and being together

Question 17

describe muller ratchet theory

Answer 17

the process which in the absence of genetic recombination (a sexual reproduction has this because there is no combination of genes - the genes come from one parent) this results in a accumulation of irreversible deleterious mutations eventually leading to the extinction of the population

Question 18

describe the red queen hypothesis

Answer 18

unique genetic composition within a species offers environmental adaption
—defence against parasites

sexual reproduction offers the opportunity for continued development to maintain evolutionary “fitness”

in other words, evolution is a race and the environment is filled with competition (viruses, parasites, different challenges to species) it’s continuously updating itself or it’s doomed

Question 19

what is evolution?

Answer 19

it is the biological changes in a process of descent with modification

adaptions to their changing environments resulting in changes genes, new traits and new species

Question 20

difference between microevolution and macroevolution

Answer 20

micro: studies changes at the DNA level or allele level

macro: studies large scale changes like the evolution of a new species which is the process of numerous microecolutionary changes

Question 21

competition vs choosiness

Answer 21

males compete for access to females

female soften choose among many males according to the males anatomical features of behaviours

Question 22

what is Batemans principal and how does it relate to competition vs choosiness

Answer 22

Female should be choosy, because female candies are more expensive (we are born with all of our eggs while males generates sperm through spermatogenesis)

female reproductive success is limited

Question 23

intrasexual vs intersexual

Answer 23

intra: competition within one sec for access to members of the opposite sex (two-males competing)

inter: choosey females choosing their male partner

Question 24

what are sexual dimorphisms? name an example

Answer 24

the difference in size and appearance between sexes of the same species

male deer have antlers while females don’t