An animal that has a diploid chromosome number of 28. How many autosomes would you find in the follow cell typ?
Autosomes are chromosomes that are not sex chromosomes (i.e. X and Y chromosomes in mammals). Mammals get 1 sex chromosome from each parent, so 2 of the 28 are sex chromosomes. The other 26 are autosomes. An egg cell has split its cromosomes with another egg cell (in a process called meiosis) to make a haploid gamete. This means there is only 1 copy of each chromosome, instead of 2. A sperm cell also has 1 copy of each chromosome and together they make a single fertilised cell with a new combination of 28 chromosomes. Each gamete (sex cell) has 14 chromosomes, one of which is a sex chromosome.
The Diploid Number of Chromosomes from a certain animal is twelve. A biologist observes a cell that contains?
The Diploid Number of Chromosomes from a certain animal is twelve. A biologist observes a cell that contains two distinct and widely separated groups of six chromosomes consisting of one chromosome each. This cell is: a in metaphase of mitosis b. in anaphase of mitosis c. in metaphase of the first division of meiosis d. in anaphase of the second division if meiosis e. between meiotic divisions and why? HELP !!
How is the number of chromosomes maintained in an organism?
I've partially answered this question here before: Akshari Gupta's answer to What will be the chromosome number in humans during different phases of mitosis and meiosis?The first thing to know is the difference between a chromatid and a chromosome.Next, let's look at the basics of chromosome numbers in mitosis.So it's more or less straightforward in mitosis:The chromosome number remains constant (46 total chromosomes or 23 pairs of chromosomes).The chromatids replicate during interphase to produce a total of 92 chromatids, but they're only found in pairs and remain connected at the center by the centromere.After mitosis, the chromatid pairs separate, so each daughter cell gets 46 chromatids.Now meiosis is tricky. Meiotic cells undergo a more complicated process to ensure the correct number of chromosomes.Here's what happens:At first the cells have the same number of chromosomes as mitosis. DNA replication occurs, giving a total of 46 chromosomes (or 23 chromosome pairs) and 92 chromatids (or 46 chromatid pairs).Meiosis I: In meiosis I, the homologous chromosomes separate. In this case, the pairs of sister chromatids are still attached to each other. So at this stage, the daughter cells get 23 chromosomes each (of the pair of homologous chromosomes) and 46 chromatids in total (which are actually 23 pairs of sister chromatids attached at the centromere). This is known as reductional division, as the total number of chromosomes is halved at this stage.Meiosis II: Meiosis II follows the same division as mitosis, except that there are only half as many chromosomes. So the 23 chromatid pairs from the previous cells (or 46 chromatids in total) split equally, so each daughter gets 23 chromatids exactly, which correspond to 23 chromosomes. Meiosis II is known as equational division.So to summarize, in mitosis, the total number of chromosomes is unchanged in the daughter cells; whereas in meiosis, the total number of chromosomes is halved in the daughter cells.Let me know if you were looking for any other kind of information; I'll update that in this answer.
Why do gametes need half the number of chromosomes of somatic cells?
Typically, humans reproduction is sexual. It involves merging haploid gamete cells from each parent with half the normal number of chromosomes to make a new cell containing both parents' genetic material. This is a diploid zygote. The cells from each parent that combine to form the zygote are called gametes.It’s a reproductive cell. In meiosis, a cell must be haploid, or have half the number of chromosomes. In humans, regular cells have 46 chromosomes. But egg and sperm cells, female and male gametes have 23, because they combine to form a diploid cell with 46 chromosomes.Basically if two somatic cells(body cells) combined to form a zygote, the zygote would have twice the number of chromosomes needed in a person, and would have to self-abort.?Almost all multicellular eukaryotic organisms that undergo sexual reproduction use gametes, or sex cells, to create offspring. Since two parents are necessary to create individuals for the next generation of the species, gametes are typically haploid cells. That way, each parent can contribute half of the total DNA to the offspring. When two haploid gametes fuse during sexual reproduction fertilization, they each contribute one set of chromosomes to make the single diploid zygote that has a full two sets of chromosomes.
Do all organisms have the same number of Chromosomes ?
No. eg. Cat 38 Chicken 78 Chimpanzee 48 Coatimundi 38 Cotton 26 Cow 60 Coyote 78 Deer mouse 48
Why is an odd number of chromosomes in a gamete important?
It is not important unless it is a human gamete and then the gamete has to have 23 chromosomes. So two gametes together (sperm and egg) will produce the first human cell with 46 chromosomes. But it would certainly be possible for an organism to normally have 32 chromosomes, for example, so its gamete would have 16. If a human gamete has more or less than 23 chrom, then it almost always dies before fertilization. In a rare case where a child is born, it will be very abnormal in some way like it might have Down Syndrome (used to be call a mongoloid child).
.In some birds and true bugs, the number of chromosomes is hard to determine since chromosomes get smaller and?
The fewer the chromosomes the better. When a cell undergoes mitosis and divides into two new cells, the chromosomes have to replicate and divide themselves. With only a few chromosomes, this is easy, fast and there will be a lesser chance of errors. But if there are a lot of chromosomes, then it will take a longer time to divide and there is a greater chance of errors. Hope this helps! =)