BIOL 206 (PART 3) EXAM REVIEW QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW
what is syngamy? Ans✓✓✓fertilization process
what are the costs to sex? Ans✓✓✓- the cost of producing males
("twofold" cost)
- the genetic cost of meiosis ("reduced relatedness")
- the cost of finding a mate (time and energy that could be spend
foraging)
- the cost of mating (Pathogens and infection)
what are the benefits of being an asexually reproducing organism
(female)? Ans✓✓✓- twice the fitness, increase in frequency over time
- twice the relatedness between parent and offspring
what are the benefits of sex? Ans✓✓✓- combining beneficial mutations
- sex generates novel genotypes through recombination (through
recombination
- faster evolution ("red queen" effect) evolutionary arms race
- sex can remove deleterious mutations "muller's ratchet"
Explain Muller's Ratchet Ans✓✓✓when asexual individuals get
deleterious mutations they cannot lose them because the ratchet has
,"clicked" forward. they can only evolve towards greater loads of
deleterious mutations (sex breaks the ratchet)
why do asexual individuals evolve? Ans✓✓✓because of the huge short-
term benefits of asexual reproduction (two-fold cost, relatedness, search,
STIs)
why do asexual species go extinct? Ans✓✓✓because the short-term
benefit of asexual reproduction is countered by the long term advantages
of sex
what does parasitism select for? Ans✓✓✓sex
if organisms can reproduce both sexually and asexually what happens?
Ans✓✓✓there is a trade-off between sexual and asexual reproduction.
depending on the environment (and other conditions), either sex or asex
will be favoured
what are four various sexual strategies? Ans✓✓✓- parthenogenesis
(organism develops from unfertilized egg)
- hermaphroditism (organisms possess both male and female
reproductive organs or change sex at some point)
- halpodiploidy (haploid males develop from unfertilized eggs, diploid
female from fertilized eggs)
- environmental sex determination (the early development determines
whether an individual will be female or male)
, what is anisogamy? Ans✓✓✓- females invest in few large gametes
- males invest in many small gametes
what does sexual selection favour? Ans✓✓✓phenotypes that get more
genes into the next generation
what can sexual selection produce? Ans✓✓✓costly conspicuous traits
that compromise survival (but may be beneficial in reproduction)
What is sexual selection? Ans✓✓✓differences in reproductive success
(fitness) among individuals as a result of differences in mating success
(via the competition for access to mates and non-random choice of
mates)
what are results of sexual selection? Ans✓✓✓- should be more
discriminating
- become a limiting resource for the opposite sex
What is sexual dimorphism? Ans✓✓✓marked differences between the
sexes in secondary sexual characteristics
what are ornaments? Ans✓✓✓attractive traits that increase mating
success
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW
what is syngamy? Ans✓✓✓fertilization process
what are the costs to sex? Ans✓✓✓- the cost of producing males
("twofold" cost)
- the genetic cost of meiosis ("reduced relatedness")
- the cost of finding a mate (time and energy that could be spend
foraging)
- the cost of mating (Pathogens and infection)
what are the benefits of being an asexually reproducing organism
(female)? Ans✓✓✓- twice the fitness, increase in frequency over time
- twice the relatedness between parent and offspring
what are the benefits of sex? Ans✓✓✓- combining beneficial mutations
- sex generates novel genotypes through recombination (through
recombination
- faster evolution ("red queen" effect) evolutionary arms race
- sex can remove deleterious mutations "muller's ratchet"
Explain Muller's Ratchet Ans✓✓✓when asexual individuals get
deleterious mutations they cannot lose them because the ratchet has
,"clicked" forward. they can only evolve towards greater loads of
deleterious mutations (sex breaks the ratchet)
why do asexual individuals evolve? Ans✓✓✓because of the huge short-
term benefits of asexual reproduction (two-fold cost, relatedness, search,
STIs)
why do asexual species go extinct? Ans✓✓✓because the short-term
benefit of asexual reproduction is countered by the long term advantages
of sex
what does parasitism select for? Ans✓✓✓sex
if organisms can reproduce both sexually and asexually what happens?
Ans✓✓✓there is a trade-off between sexual and asexual reproduction.
depending on the environment (and other conditions), either sex or asex
will be favoured
what are four various sexual strategies? Ans✓✓✓- parthenogenesis
(organism develops from unfertilized egg)
- hermaphroditism (organisms possess both male and female
reproductive organs or change sex at some point)
- halpodiploidy (haploid males develop from unfertilized eggs, diploid
female from fertilized eggs)
- environmental sex determination (the early development determines
whether an individual will be female or male)
, what is anisogamy? Ans✓✓✓- females invest in few large gametes
- males invest in many small gametes
what does sexual selection favour? Ans✓✓✓phenotypes that get more
genes into the next generation
what can sexual selection produce? Ans✓✓✓costly conspicuous traits
that compromise survival (but may be beneficial in reproduction)
What is sexual selection? Ans✓✓✓differences in reproductive success
(fitness) among individuals as a result of differences in mating success
(via the competition for access to mates and non-random choice of
mates)
what are results of sexual selection? Ans✓✓✓- should be more
discriminating
- become a limiting resource for the opposite sex
What is sexual dimorphism? Ans✓✓✓marked differences between the
sexes in secondary sexual characteristics
what are ornaments? Ans✓✓✓attractive traits that increase mating
success
