unit 2 biology cover Flashcards
In asexual reproduction, what happens?
Just one parent can produce daughter cells and establish a colony of virtually unlimited size over time.
Where is maintaining the genome of the parent an advantage?
Particularly in very narrow, stable niches or when re-colonising disturbed habitats.
What are the benefits of external fertilisation?
Very large numbers of offspring can be produced.
What are the costs of external fertilisation?
Many gametes predated or not fertilised; no or limited parental care; few offspring survive.
What are the benefits of internal fertilisation?
Increased chance of successful fertilisation; fewer eggs needed; offspring can be retained internally for protection and/or development; higher offspring survival rate.
What are the costs of internal fertilisation?
A mate must be located, which requires energy expenditure; requires direct transfer of gametes from one partner to another.
What happens at the lek?
Dominant males occupy the centre of the lek, with subordinates and juveniles at the fringes as ‘satellite’ males.
What is an ecological niche?
A multi-dimensional summary of tolerances and requirements of a species.
What are viruses?
Parasites that can only replicate inside a host cell.
What are viral life stages?
Infection of host cell with genetic material, host cell enzymes replicate viral genome, transcription of viral genes and translation of viral proteins, assembly and release of new viral particles.
Why may it be difficult to design vaccines?
Some parasites are difficult to culture in the laboratory.
What do improvements in parasite control do?
Reduce child mortality and result in population-wide improvements in child development and intelligence, as individuals have more resources for growth and development.
