topic 3 reproduction Flashcards
What is sexual reproduction?
-Type of reproduction.
● Involves the production of gametes by meiosis.
● A gamete from each parent fuses to form a zygote.
● Genetic information from each gamete is mixed so the resulting zygote is unique.
What are gametes?
sex cells, they are haploid
what is meiosis?
form of cell division involved in the formation of gametes
chromosome number is halved
involves two divisions
what must occur prior to meiosis?
Interphase
Why is meiosis important for sexual reproduction?
● It increases genetic variation
● It ensures that the resultant zygote is diploid
What is the advantage of sexual reproduction?
It creates genetic variation in offspring, increasing the probability of a species adapting to and surviving environmental changes.
Describe the disadvantages of sexual reproduction.
● Two parents are required. This makes reproduction difficult in endangered populations or in species which exhibit solitary lifestyles.
● More time and energy is required so fewer offspring are produced.
What is asexual reproduction?
● Type of reproduction.
● Involves mitosis only.
● Produces genetically identical offspring known as daughter cells.
Describe the advantages of asexual reproduction
● Only one parent is required.
● Lots of offspring can be produced in a short period of time, enabling the rapid colonisation of an area and reducing competition from other species.
● Requires less energy and time as do not need a mate.
What is a disadvantage of asexual reproduction?
no genetic variation reducing the probability of a species being able to adapt to environmental change
