2.3 a) Costs and Benefits of Sexual and Asexual Reproduction Flashcards
Sexual reproduction involves __ individuals of the ___ species.
two, same
What are the two costs of sexual reproduction?
- males are unable to produce offspring
- only half of each parents genome is passed onto offspring, which disrupts successful genomes
The benefits of sexual reproduction ___ the costs, due to an increase in…
outweigh, genetic variation
Genetic variation provides the raw ___ required for ___, giving sexually reproducing organisms a ___ chance of survival under changing ___ ___.
materials, adaptation, better, selection pressures
The Red Queen Hypothesis explains the persistence of ___ ___ because _-___ interactions between ___ and ___ may select for ___ reproducing hosts.
sexual reproduction, co-evolutionary, parasite and host, sexually
Hosts that are better able to resist and tolerate ___ have greater ___.
parasitism, fitness
Parasites that are better able to ___, ___ and find new ___ have greater ___.
feed, reproduce, hosts, fitness
If hosts reproduce sexually, the ___ ___ in their offspring reduces the chances that they will all be ___ to infection by ___.
genetic variation, susceptible, parasites
How does sexual reproduction decrease parasitism in offspring?
the offspring have increased genetic diversity which decreases the chances of all offspring being susceptible to infection
Asexual reproduction can be a successful reproductive strategy as…
whole genomes are passed on from parent to offspring
Asexual reproduction involves ___ individual.
one
In asexual reproduction, just ___ parent can produce ___ cells and establish a ___ of virtually ___ size over time.
one, daughter, colony, unlimited
Maintaining the genome of the parent is beneficial in very ___, ___ ___ or when _-___ disturbed habitats.
narrow, stable niches, re-colonising
Examples of asexual reproduction in eukaryotes includes ___ ___ in plants and ___ in lower plants and animals that lack ___.
vegetative cloning, parthenogenesis, fertilisation
What is parthenogenesis?
reproduction from a female gamete without fertilisation
One of the downsides to sexual reproduction is that males are ___ to produce offspring.
What is it called when females produce offspring without fertilisation?
unable
parthenogenesis
Offspring can be produced more often and in larger numbers with ___ reproduction.
asexual
Parthenogenesis is more common in ___ climates (which are disadvantageous to ___), and in areas with low ___ ___.
cooler, parasites, parasite density
Why is parthenogenesis more common in areas with less parasites?
because parasites have an easy time infecting / switching between parent and offspring of asexual reproduction, because there is less genetic diversity
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.
adapt, environment, mutations, genetic variation, natural selection, evolution
Organisms which reproduce by asexual reproduction often have mechanisms for ___ ___ ___ between individuals to increase ____.
horizontal gene transfer, variation
What is an example of horizontal gene transfer?
the transfer of plasmids between bacteria
(prokaryotes do horizontal gene transfer)
Horizontal gene transfer results in ___ ___ change than in organisms which only use ___ transfer.
faster evolutionary, vertical
When is maintaining the genome of the parent an advantage?
when re-colonising habitats or in stable, narrow niches
Why do many marine organisms use external fertilisation??
because the water allows the sperm to swim to the eggs
