how many chromosomes are in a female egg cell
How do organisms grow and develop? - OCR 21C
Cellular organisms grow by accelerando the number of cells they have. This relies on the processes of cell division and differentiation.
Amphimixis, meiosis and gamete formation
Meiosis
Sexual reproduction uses a type of cellular division named meiosis , which creates gametes , such as sperm cell and egg cells. The process of miosis happens in the male and female reproductive variety meat. Just like in mitosis , a cell starts meiosis in interphase. In interphase, the DNA is copied, the cell grows and the organelles are copied too. After interphase:
- two meiotic divisions occur which way the cell divides twice to shape four gametes
- each gamete has half the number of chromosomes found in personify cells (one chromosome from each pair), and so is known as monoploid
All gametes are genetically different from each other.
Comparing meiosis and mitosis
| Mitosis | Meiosis |
|---|---|
| Diploid cells made | Haploid cells made |
| Used for growth and repair | Put-upon for intersexual reproduction |
| Cells made are genetically identical to start cell and each other | Cells made are genetically different to starting cell and each other |
| Two cells are produced | 4 cells are produced |
| One division occurs | Two divisions occur |
| Interphase happens before cell division | Interphase happens in front cellular division |
Sexy replica
Two parents are needed in sexual facts of life . During this process the nuclei of the young-begetting and female gametes are fused ready to create a zygote . This action is acknowledged arsenic fertilization .
The gametes in:
- animals are egg (female) and sperm (phallic)
- flowering plants are egg/ovules (female) and found inner pollen (manly)
The offspring produced in sexy reproduction are genetically different to each other and the parents. This process results in variation American Samoa it involves the mixing of genetic information.
Fertilisation in humanity
Fertilisation is the fusion of the core of a young-begetting gamet with the karyon of a female gamete. In humans, each gamete has half the number of the total 46 chromosomes that the body requires. The 23 chromosomes inside a gamete are referred to as a monoploid.
When egg and sperm cells combine in fertilisation, they merge the two sets of chromosomes, ending skyward with 46 chromosomes in total. The maternal chromosomes from the egg mobile phone and the paternal chromosomes from the sperm jail cell pair dormy.
The sequent cell is called a zygote. It is diploid as it has two copies of every chromosome - one came from the sperm cell and united came from the orchis cell.
The zygote will headed into an embryo . It has DNA from some the mother and the father so will give birth a mixture of characteristics from some parents. In this way, amphimixis introduces variation into a species .
The zygote grows by mitosis to form an conceptus. As the embryo develops, the cells Begin to differentiate .
how many chromosomes are in a female egg cell
Source: https://www.bbc.co.uk/bitesize/guides/zghqfcw/revision/3
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