0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
Why must the sex cells have half the chromosome number of the normal body cells?
Otherwise, after fertilisation, the number of chromosomes would be doubled. Then, after each generation, the number of chromosomes would continue to be doubled! One might argue that after fertilisation, meiosis could take place, that is, the halving of the number of chromosomes could take place. It is true, but rare. Some organisms use this method.
Why might Cells from an advanced malignant tumor most often have very abnormal chromosomes and often an abnormal total number of chromosomes?
Chromosomally abnormal cells can still go through cell cycle checkpoints.
For what reasons might a cell use meiosis?
All human cells have 46 chromosomes, 23 pairs. In sexual reproduction, if an egg and a sperm each with 46 chromosomes joined then the zygote would have 92 chromosomes. To keep this from happening, cells undergo meiosis. In meiosis the cells replicate the chromosomes and divide then divide again so they end up with only 23 chromosomes. Cells with half the number of chromosomes are called gametes.
What might happen inf the gametes of a species has the same number of chromosomes as the species' body cells?
in human being's normal cells 46 chromosomes are found whereas in gametes half of the chromosomes,that is;23 are found if gametes will have same no. of chromosomes as in normal cells than in offspring (46+46=92)chromosomes will be found but it can't happen
What might different sized eukaryote having chromosomes suggest about the size and organization of chromosomes in different species?
Identify the stages of these cells
What are sperm or eggs that contain half the number of chromosomes as the body cells called?
The egg cell and the sperm cell contain half the number of chromosomes as all other body cells because during fertilisation they help to restore the chromosome number in zygote. If this is not half then the chromosome number in zygote will exceed the chromosomal no. of parents. This may lead to abnormal deformities.
Why is it necessary to have a haploid cell at the end of meiosis?
In most plants and animals, each cell has two copies of each chromosome. Cells having 2 of each kind of chromosome are called diploid. For instance, human cells have 46 chromosomes (23 different kinds of chromosomes, and 2 copies of each kind). They are diploid. Now think about what happens when a sperm fertilizes an egg. If a sperm has 46 chromosomes, and an egg has 46 chromosomes, then you might think that the fertilized egg would have 92 chromosomes since it is formed by putting together the sperm and the egg. But this doesn't happen. Why not?Sperm cells and egg cells are produced by a process of cell division called meiosis that cuts the number of chromosomes in half (each sperm cell has 23 chromosomes and each egg cell has 23 chromosomes). Then when the sperm and egg combine during fertilization, they produce a cell that has the normal number of chromosomes again. (23 + 23 = 46). Meiosis reduces the number of chromosomes by putting one of each kind instead of two of each kind in each sperm and in each egg. Cells that have only one copy of each kind of chromosome are called haploid. Sperm cells and egg cells are haploid. All other cells in the body have two of each kind of chromosome and are called diploid.
What might happen to a new cell if it didn't have the same amount of chromosomes as the original cell?
Then it's a prokaryote cell (such as bacteria). If not a prokaryote then it just wouldn't be a cell because with eukaryote cells, if there are no chromosomes, there is no cell or life with that cell.
What might this suggest about the size and organization of chromosomes in different species?
they contain the same number of chromosome's :)
What are uses of meiosis?
Meiosis is used to make gametes in the human body. The gametes will either be sperm or eggs depending on the gender.
How can a zygote end up with an extra chromosome?
how could a zygote end up with an extra chromosome Either the egg or the sperm doesn't divide equally.
List three situations in which DNA testing might be indicated?
1.) Forty -six chromosomes (23 pairs) are found inside the nucleus of every human cell, except egg and sperm cells, which have 23 chromosomes each.
