Variation and sexual reproduction Flashcards
Costs of sexual reproduction
Males are unable to produce offspring
Only half of each parents genome passed onto offspring which can disrupt the successful parental genome
Benefits of sexual reproduction
Benefits outweigh the costs due to an increase in genetic variation in the population.
What does genetic variation provide?
Raw materials required for adaption, giving sexually reproducing organisms a better chance of survival under changing selection pressures
Co-evolutionary interactions between parasites and hosts may select for sexually reproducing hosts
Hosts better able to resist and tolerate parasitism have greater fitness. Parasites better able to feed, reproduce and find new hosts have greater fitness
If hosts reproduce sexually what happens to the genetic variability of offspring?
It reduces the chances that all will be susceptible to infection by parasites.
How is asexual reproduction more successful?
Whole genomes are passed on from parent to offspring which is an advantage in particularly narrow, stable niches or when re-colonising disturbed habitats.
What is asexual reproduction?
Just one parent can produce daughter cells and establish a colony of virtually unlimited size over time.
What is parthenogenesis?
The reproduction from a female gamete without fertilisation
Examples of asexual reproduction in plants?
Vegetative cloning in plants and parthenogenesis in lower plants and animals that lack fertilisation.
How is asexual reproduction advantageous?
Offspring can be produced more often and in larger numbers
Benefits of parthogenesis?
It is more common on cooler climates which deters parasites, or regions of low parasite density or diversit.
Asexual reproduction populations ____ able to ____easily to changes in their ________ environments, but _________ can occur that provide some ______ __ ______ and enable some natural _______ _______ and _________ to occur
Are not Adapt Environment Mutations Degree of Variation Natural Selection Evolution
What can asexual do to increase variation?
Horizontal gene transfer
How can prokaryotes effect the rate of evolutionary change?
They can exchange material horizontally resulting in faster revolutionary change than in organisms that only use vertical transfer.
