Difference between revisions of "Chromosome"
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: 23 '''chromosomes''' are from the father and 23 '''chromosomes''' are from the mother. | : 23 '''chromosomes''' are from the father and 23 '''chromosomes''' are from the mother. | ||
: The last 2 ''chromosomes''' are called sex '''chromosomes''' and they determine if the [[offspring]] is [[male]] or [[female]]. If the human has two [[X Chromosome]]s then they are [[female]]. If the human has an X and a [[Y Chromosome]] they are [[male]]. | : The last 2 ''chromosomes''' are called sex '''chromosomes''' and they determine if the [[offspring]] is [[male]] or [[female]]. If the human has two [[X Chromosome]]s then they are [[female]]. If the human has an X and a [[Y Chromosome]] they are [[male]]. | ||
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| + | ===References=== | ||
| + | ====AQA==== | ||
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| + | :[https://www.amazon.co.uk/gp/product/0008158754/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158754&linkCode=as2&tag=nrjc-21&linkId=27ad53b0283feeff7fc5ae04a9e205f155 ''Chromosome, pages 14, 24-2, 35, 41, 208, 212, 236-9, 240, 242-3, 250-1, GCSE Biology; Student Book, Collins, AQA ''] | ||
Revision as of 11:52, 3 November 2019
Contents
Key Stage 3
Meaning
Chromosomes are coils of DNA found in the nucleus.
 |
| This diagram shows how DNA is coiled up to make a chromosome. |
About Human Chromosomes
- Humans have 46 chromosomes.
- Chromosomes come in pairs, one from the father and one from the mother.
- 23 chromosomes are from the father and 23 chromosomes are from the mother.
- The last 2 chromosomes are called sex chromosomes and they determine if the offspring is male or female. If the human has two X Chromosomes then they are female. If the human has an X and a Y Chromosome they are male.
Key Stage 4
Meaning
A chromosome is a section of DNA that has coiled together.
About Chromosomes
- Chromosomes are found in pairs in diploid cells.
- In organisms which engage in sexual reproduction one of the chromosomes in the pair is inherited from the mother and the other from the father.
- During mitosis chromosomes have made copies of themselves that are joined by a centromere.
- In haploid cells there are half the number of chromosomes. These cells are gametes used in sexual reproduction.
About Human Chromosomes
- Humans have 46 chromosomes.
- 23 chromosomes are from the father and 23 chromosomes are from the mother.
- The last 2 chromosomes' are called sex chromosomes and they determine if the offspring is male or female. If the human has two X Chromosomes then they are female. If the human has an X and a Y Chromosome they are male.