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A chromosome is a thread like structure of nucleic acids and protein found in the nucleus of living cells. It carries genetic information in the form of genes.
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∙ 9y ago
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Who has to give DNA?
both parents have to give 23 cromizones
What happens when a fetus has 3 cromizones instead of 2?
a "normal" human being should have a total of 46 chromosomes. 23 from mom, 23 from dad. if something goes wrong during meiosis, the chromosomes may not be separated normally and a gamete (sex cell, known as sperm or egg) will have either too few or too many chromosomes. this is known as aneuploidy. the effects of aneuploidy on the zygote will vary depending on what chromosomes you are talking about. in the case of chromosome #21, having one extra is called "trisomy 21" which leads to the condition known as down syndrome. chromosome pairs 1-22 are a person's autosomes. the 23rd pair are sex chromosomes. aneuploidy affecting the sex chromosomes can have various effects, depending on what chromosomes are inherited. as you can see, the effects of aneuploidy depend on the specific chromosome number/pair. aneuploidy usually is not fatal.
