Bio 345 EXAM 2 Questions and
Answers 100% Pass
Parthenogenesis - ✔✔A form of asexual reproduction where development
of the embryo does not require fertilization (sperm not necessary). Cloning
ones self. Only 1% of plants do this. Only 0.15 of animals do this.
Bdelloid rotifers - ✔✔over 300 species - all cloned females, asexual
reproduction for 100 million years.
group of small aquatic animals has lived in sexual abstinence for more than
100 million years
Twofold cost of males - ✔✔If all else is equal, the production of males in a
sexual population reduces its reproductive potential by a factor of two
1
100% Pass Guarantee Katelyn Whitman, All Rights
,Why is asexual reproduction more effective than sexual reproduction (in
accordance to population size) - ✔✔In short, a mutation for asexual
reproduction enjoys a 100 percent fitness advantage over an allele for
sexual reproduction, and it will spread to fixation in only a handful of
generations
What is the evolutionary advantage to parthenogenesis? - ✔✔No need to
find a mate! Helpful in Amphioxous. Also helps in the ability to colonize a
new habitat.
Also, no risk of sexually transmitted diseases.
What is the most fundamental feature of sexual reproduction (advantage) -
✔✔It causes genetic mixing: zygotes carry combinations of alleles inherited
from two parents. In most eukaryotes, the mixing results from segregation
and recombination that happen during meiosis, and then fusion of the
sperm and egg.
What form of reproduction is more common in changing environments? -
✔✔Sexual reproduction.
2
100% Pass Guarantee Katelyn Whitman, All Rights
, Red Queen Hypothesis - ✔✔the hypothesis that sexual selection allows
hosts to evolve at a rate that can counter the rapid evolution of parasites
Example of Red Queen Hypothesis - ✔✔New Zealand mud snail
(Potamopyrgus antipodarum), which has both sexual and asexual
genotypes. Populations that are exposed to higher densities of parasites
have higher frequencies of sexually reproducing individuals. Furthermore,
because sexual females have lower infection rates, the fitness of sexual
females is sometimes more than twice that of asexual females.
How can parasites and pathogens BENEFIT from genetic mixing by
recombination? - ✔✔People develop immunity to the genotypes of
influenza virus they have been exposed to. New outbreaks result when a
novel viral genotype is produced that can efficiently infect humans. The
genome of the influenza virus is not a single molecule, as in most viruses.
Instead, its genome is broken into eight segments of RNA. This
arrangement is an adaptation that enhances recombination. You can think
of the next outbreak of the flu as a dramatic demonstration of the
evolutionary power of recombination.
3
100% Pass Guarantee Katelyn Whitman, All Rights
Answers 100% Pass
Parthenogenesis - ✔✔A form of asexual reproduction where development
of the embryo does not require fertilization (sperm not necessary). Cloning
ones self. Only 1% of plants do this. Only 0.15 of animals do this.
Bdelloid rotifers - ✔✔over 300 species - all cloned females, asexual
reproduction for 100 million years.
group of small aquatic animals has lived in sexual abstinence for more than
100 million years
Twofold cost of males - ✔✔If all else is equal, the production of males in a
sexual population reduces its reproductive potential by a factor of two
1
100% Pass Guarantee Katelyn Whitman, All Rights
,Why is asexual reproduction more effective than sexual reproduction (in
accordance to population size) - ✔✔In short, a mutation for asexual
reproduction enjoys a 100 percent fitness advantage over an allele for
sexual reproduction, and it will spread to fixation in only a handful of
generations
What is the evolutionary advantage to parthenogenesis? - ✔✔No need to
find a mate! Helpful in Amphioxous. Also helps in the ability to colonize a
new habitat.
Also, no risk of sexually transmitted diseases.
What is the most fundamental feature of sexual reproduction (advantage) -
✔✔It causes genetic mixing: zygotes carry combinations of alleles inherited
from two parents. In most eukaryotes, the mixing results from segregation
and recombination that happen during meiosis, and then fusion of the
sperm and egg.
What form of reproduction is more common in changing environments? -
✔✔Sexual reproduction.
2
100% Pass Guarantee Katelyn Whitman, All Rights
, Red Queen Hypothesis - ✔✔the hypothesis that sexual selection allows
hosts to evolve at a rate that can counter the rapid evolution of parasites
Example of Red Queen Hypothesis - ✔✔New Zealand mud snail
(Potamopyrgus antipodarum), which has both sexual and asexual
genotypes. Populations that are exposed to higher densities of parasites
have higher frequencies of sexually reproducing individuals. Furthermore,
because sexual females have lower infection rates, the fitness of sexual
females is sometimes more than twice that of asexual females.
How can parasites and pathogens BENEFIT from genetic mixing by
recombination? - ✔✔People develop immunity to the genotypes of
influenza virus they have been exposed to. New outbreaks result when a
novel viral genotype is produced that can efficiently infect humans. The
genome of the influenza virus is not a single molecule, as in most viruses.
Instead, its genome is broken into eight segments of RNA. This
arrangement is an adaptation that enhances recombination. You can think
of the next outbreak of the flu as a dramatic demonstration of the
evolutionary power of recombination.
3
100% Pass Guarantee Katelyn Whitman, All Rights
