Cell division is the process that cells go through in order to divide. Cells may divide for several reasons, and there are two types of cell division depending on the purpose. The cell division associated with sexual reproduction is one type, called meiosis. The other type, the cell division associated with growth and cell replacement or repair, is called mitosis. In both types of cell division, the nucleus splits and DNA is replicated.
The cell division called mitosis produces daughter cells that have all the genetic material of the parent cell — a complete set of chromosomes. However, chromosomes are not the only material that needs to be divided and transferred to the daughter cells: there are cytoplasm and the cell membrane to divide as well. Cytokinesis is the process of dividing the cytoplasm and the cell membrane, and this process may follow immediately after mitosis or occur separately, depending on the organism involved. Together, these two processes make up the mitotic phases of the cell cycle.
The phases of cell division are prophase, metaphase, anaphase, and telophase, and these occur in both mitosis and meiosis. A fifth phases called prometaphase occurring between prophase and metaphase is designated by some, but not all sources. Interphase, which is not part of mitosis, is a preparatory stage during which the parent cell makes a copy of its genetic material so that each daughter cell can have a complete set. Therefore, mitosis is an ongoing and repetitive process, alternating with interphase.
Meiosis, on the other hand, reduces the number of chromosomes by half, so that, for example, human egg and sperm cells, called gametes, each have 23 chromosomes and can join to produce a zygote with 46. It has two division phases, whereas mitosis has only one. Meiosis in animals is called gametogenesis, specifically, spermatogenesis, producing sperm, in males and oogenesis, producing eggs or ova, in females. In the unfused state, the egg and sperm are called haploid cells — having only a single set of chromosomes, and they become diploid — having a pair of each type of chromosome — again when they unite during fertilization.
Meiosis specifically works to combine the genetic material of two individuals. When there is only one parent in the reproductive cycle — for example, in ferns, which reproduce through spore — the daughter cell must have the full genetic material — all the chromosomes — of the parent cell. Therefore, in the case of the creation of spore — sporogenesis — reproduction is accomplished without meiosis.
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anon332478
Post 39 |
Which energy works in cell division, and is it the same energy as in meiosis cell division? |
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anon320413
Post 38 |
Why is cell division so important? |
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anon319641
Post 37 |
The purpose of cell division is to make up all the organs' parts inside the baby's body. |
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anon228852
Post 29 |
how many cells can an adult man produce in a second?
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anon222236
Post 28 |
What are the purposes of cell division? |
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anon166929
Post 26 |
why is cell division needed? |
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anon156412
Post 25 |
what are the seven reasons for cell division? |
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anon137302
Post 23 |
i am a student studying in grade 8 and i am having difficulty in answering the following question: why do cells have to divide after they reach a certain size? please answer this question for me. |
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anon118521
Post 21 |
What is the purpose of cell division in single celled organism? |
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anon115073
Post 19 |
what is needed for cell division?
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anon103652
Post 18 |
so what part is it, when removed, the cell won't reproduce? |
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anon90891
Post 17 |
what is the purpose of each cell division? where does it take place? |
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anon88846
Post 16 |
i am in grade 8. can you please tell me the difference between fertilization and pollination?
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anon83668
Post 15 |
so helpful! thank you so much! |
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anon82454
Post 14 |
how do these factors affect cell division: time of day; stress; inflammation. |
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anon81983
Post 13 |
how does it work? |
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anon78981
Post 12 |
what are the two major reasons for cell division? |
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anon63709
Post 11 |
why do cells undergo cell division? for what purpose? |
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anon59813
Post 10 |
what parts of the cell are important in cell reproduction? |
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anon57279
Post 9 |
what role does cell division have in healing the body?
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anon50934
Post 6 |
why is cell division so important? |
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anon47331
Post 5 |
are all cells the same size? |
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anon40027
Post 3 |
why is each stage of the cell cycle a prerequisite to the other? |
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anon178
Post 1 |
what is the purpose of cell division? |
