reproduction 2.3 Flashcards
what is sexual reproduction
the fusion of two gametes nuclei during fertilisation
what is reproduction
the process by which members of a species produce offspring
what are gametes
organisms reproductive cells also known as sex cells
examples of gametes
- egg cell
- sperm cell
- pollen grains
- ovule
sperm cell
- consists of a head region that contains the nucleus
- have a long streamlike tail to help them swim towards the egg
- contains lots of mitochondria
egg cell
- the egg cell contains a food store in the cytoplasm for growing the embryo
- much larger than the sperm cell
where are sperm cells produced
testes
where are egg cells produced
ovaries
what is fertilisation
the fusion of the nuclei of 2 haploid gametes to produce a diploid zygote, which divides to form an embryo
what type of chromosome does the egg cell have
X chromosome
what type of chromosome does the sperm cell have
X or Y chromosomes
stages of fertilisation
1) egg is released from ovary
2) the egg is picked up by funnel of oviduct fringed with hair-like cilia
3) egg moves along oviduct
4) sperm fertilises egg
where does fertilisation occur
in the oviduct
what do pollen grains contain
the plants male sex cells
where are the plants male gametes produced
the anthers
what contains the plants female sex cell
the ovule
what is the plants female sex organ
ovary
what is pollination
the transfer of pollen grains from the anther to the stigma
how is pollination achieved
by insects such as bees or the wind
stages of fertilisation in plants
1) when pollen grains land on the stigma, they use the sugar on the stigma to form a pollen tube which grows down through the stigma to the ovary
2) the pollen grains male nucleus and the ovules female nucleus fuse together during fertilisation
3) the fertilised ovule turns into a seed containing an embryo and a food store
