biology - 2.3a - costs and benefits of sexual and asexual reproduction Flashcards
What is the costs of sexual reproduction? (2)
Only half of each
parent’s genome passed onto offspring,
disrupting successful parental genomes.
Why do benefits outweigh costs?
Due to an increase in genetic variation in the population.
What does genetic variation provide?
The raw material required for adaptation, giving sexually reproducing organisms a better chance of survival under changing selection pressures.
What does the Red Queen hypothesis explain?
The persistence of sexual reproduction.
What may select for sexually reproducing hosts?
Co-evolutionary interactions between parasites and hosts.
Which hosts and parasites have greater fitness?
Hosts better able to resist and tolerate parasitism.
Parasites better able to feed, reproduce and find new hosts have better fitness.
If hosts reproduce sexually, what does this do?
The genetic variability in their offspring reduces the chances that all will be susceptible to infection by parasites.
Why can asexual reproduction be a successful reproductive strategy?
As whole genomes are passed on from parent to offspring.
In asexual reproduction, what can just one parent produce?
Daughter cells and establish a colony of virtually unlimited size over time.
What is maintaining the genome of the parent an advantage in?
Very narrow, stable niches or when re-colonising disturbed habitats.
What are examples of asexual reproduction in eukaryotes?
Vegetative cloning in plants and parthenogenesis in lower plants and animals that lack fertilisation.
What is parthenogenesis?
Reproduction from a female gamete without fertilisation.
Where can offspring be reproduced ore often and in larger numbers?
With asexual reproduction.
Where is parthenogenesis more common?
In cooler climates, which are disadvantageous to parasites, or regions of low parasite density or diversity.
What are asexually reproducing populations not able to do?
Adapt easily to changes in their environment, but mutations can occur that provide some degree of variation and enable some natural selection and evolution to occur.
