Sexual + Asexual reproduction Flashcards
Asexual reproduction
No variation, only clones, genetically identical
Sexual reproduction
variation, unique offspring
Haploid
has 23 chromosomes
Diploid
has 46 chromosomes
Stage 1 of meiosis
Cells making gametes has full set of chromosomes
Chromosomes copy themselves and stay attached to each other
Stage 2 of meiosis
The cell splits in two, each cell getting half of the chromosomes
Gametes
Sex cells
Fertilisation
The stage of sexual reproduction when gametes fuse. This is the first step in the creation of a new life
What happens when an egg cell fertilises
it becomes a zygote
How does a zygote become an embryo
Divides by mitosis multiple times until it is an embryo
Advantages of sexual reproduction
genetic variation
if environmental conditions change, it is more likely that some individuals will adapt
Advantages of asexual reproduction
can produce lots of offspring very quickly
Only one parent is needed
Disadvantage of sexual reproduction
takes more time and energy
two parents are needed - problems for isolated species
Disadvantages of asexual reproduction
No genetic variation
if unfavourable environmental changes occur, whole population is at risk
