Topic 3 – Genetics-Reproduction Flashcards
What is sexual reproduction?
type of reproduction
involves production of gametes by meiosis
a gamete from each parent fuses to form a gamete
genetic information from each gamete is mixed so resulting zygote in unique
what are gametes?
sex cells (sperm and egg cells) haploid (half number of chromosomes)
what is meiosis
form of cell division involved in formation of gametes
chromosome number is halved
involves 2 divisons
what must occur to meiosis?
interphase
what happens during first stage of meiosis?
Chromosomes pairs line up along cell equator
pair of chromosomes are separated and move to opposite poles of cells
chromosome number is halved
what happens during second stage of meiosis?
chromosomes line up along cell equator
chromatids separate and move to opposite poles of cell
4 unique gametes are produced
why is meiosis important for sexual reproduction?
increases genetic variation
ensures resultant zygote is diploid
what is advantage of sexual reproduction?
creates genetic variation, increasing probability of species adapting to and surviving environmental changes
describe disadvantage of sexual reproduction
2 parents are required, makes reproduction difficult in endangered population 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
produce genetically identical offspring known as daughter cells
describe advantages of asexual reproduction
only one parent is needed
lots of osspring can be reproduced in short period of time, enabling rapid colonisation of area and reduce competition from other species
requires less energy
describe disadvantages of asexual reproduction
no genetic variation reducing probability of species being able to adapt to environmental change
