2.3 a) Costs and Benefits of Sexual and Asexual Reproduction

Question 1

Sexual reproduction involves __ individuals of the ___ species.

Answer 1

two, same

Question 2

What are the two costs of sexual reproduction?

Answer 2

1. males are unable to produce offspring
2. only half of each parents genome is passed onto offspring, which disrupts successful genomes

Question 3

The benefits of sexual reproduction ___ the costs, due to an increase in…

Answer 3

outweigh, genetic variation

Question 4

Genetic variation provides the raw ___ required for ___, giving sexually reproducing organisms a ___ chance of survival under changing ___ ___.

Answer 4

materials, adaptation, better, selection pressures

Question 5

The Red Queen Hypothesis explains the persistence of ___ ___ because _-___ interactions between ___ and ___ may select for ___ reproducing hosts.

Answer 5

sexual reproduction, co-evolutionary, parasite and host, sexually

Question 6

Hosts that are better able to resist and tolerate ___ have greater ___.

Answer 6

parasitism, fitness

Question 7

Parasites that are better able to ___, ___ and find new ___ have greater ___.

Answer 7

feed, reproduce, hosts, fitness

Question 8

If hosts reproduce sexually, the ___ ___ in their offspring reduces the chances that they will all be ___ to infection by ___.

Answer 8

genetic variation, susceptible, parasites

Question 9

How does sexual reproduction decrease parasitism in offspring?

Answer 9

the offspring have increased genetic diversity which decreases the chances of all offspring being susceptible to infection

Question 10

Asexual reproduction can be a successful reproductive strategy as…

Answer 10

whole genomes are passed on from parent to offspring

Question 11

Asexual reproduction involves ___ individual.

Answer 11

one

Question 12

In asexual reproduction, just ___ parent can produce ___ cells and establish a ___ of virtually ___ size over time.

Answer 12

one, daughter, colony, unlimited

Question 13

Maintaining the genome of the parent is beneficial in very ___, ___ ___ or when _-___ disturbed habitats.

Answer 13

narrow, stable niches, re-colonising

Question 14

Examples of asexual reproduction in eukaryotes includes ___ ___ in plants and ___ in lower plants and animals that lack ___.

Answer 14

vegetative cloning, parthenogenesis, fertilisation

Question 15

What is parthenogenesis?

Answer 15

reproduction from a female gamete without fertilisation

Question 16

One of the downsides to sexual reproduction is that males are ___ to produce offspring.
What is it called when females produce offspring without fertilisation?

Answer 16

unable

parthenogenesis

Question 17

Offspring can be produced more often and in larger numbers with ___ reproduction.

Answer 17

asexual

Question 18

Parthenogenesis is more common in ___ climates (which are disadvantageous to ___), and in areas with low ___ ___.

Answer 18

cooler, parasites, parasite density

Question 19

Why is parthenogenesis more common in areas with less parasites?

Answer 19

because parasites have an easy time infecting / switching between parent and offspring of asexual reproduction, because there is less genetic diversity

Question 20

Asexually reproducing populations are not able to ___ easily to changes in their ___, but ___ can occur which provide a small degree of ___ ___, which means some ___ ___ and ___ will occur.

Answer 20

adapt, environment, mutations, genetic variation, natural selection, evolution

Question 21

Organisms which reproduce by asexual reproduction often have mechanisms for ___ ___ ___ between individuals to increase ____.

Answer 21

horizontal gene transfer, variation

Question 22

What is an example of horizontal gene transfer?

Answer 22

the transfer of plasmids between bacteria
(prokaryotes do horizontal gene transfer)

Question 23

Horizontal gene transfer results in ___ ___ change than in organisms which only use ___ transfer.

Answer 23

faster evolutionary, vertical

Question 24

When is maintaining the genome of the parent an advantage?

Answer 24

when re-colonising habitats or in stable, narrow niches

Question 25

Why do many marine organisms use external fertilisation??

Answer 25

because the water allows the sperm to swim to the eggs