B 10.1 Sexual reproduction Flashcards
(12 cards)
What is sexual reproduction?
Reproduction involving the fusion of male and female gametes to produce genetically different offspring.
What are gametes?
Sex cells (e.g., sperm, egg, pollen, ovule) that carry half the genetic information (haploid).
What is fertilisation?
The fusion of male and female gametes to form a zygote.
What is a zygote?
A fertilised egg cell with a full set of chromosomes (diploid), half from each parent.
Why does sexual reproduction produce variation?
Because the offspring inherit a mix of alleles from both parents.
What is meiosis?
A type of cell division that produces four gametes, each with half the number of chromosomes.
What happens to chromosome number in meiosis?
It is halved — gametes have one set of chromosomes.
What happens to chromosome number at fertilisation?
It is restored — the zygote has a full set of chromosomes.
Why is meiosis important in sexual reproduction?
It ensures the correct number of chromosomes in offspring and increases genetic variation.
How many cells are produced in meiosis?
Four genetically different gametes.
Where does meiosis occur?
In reproductive organs (e.g., testes and ovaries in animals, anthers and ovaries in plants).
What is meant by the term ‘haploid’?
A cell with half the normal number of chromosomes (e.g., a gamete).
