Cell division is the process by which a parent cell divides into two or more daughter cells.[1]Cell division usually occurs as part of a larger cell cycle. In eukaryotes, there are two distinct types of cell division: a vegetative division, whereby each daughter cell is genetically identical to the parent cell (mitosis),[2] and a reproductive cell division, whereby the number of chromosomes in the daughter cells is reduced by half to produce haploid gametes(meiosis). Meiosis results in four haploid daughter cells by undergoing one round of DNA replication followed by two divisions. Homologous chromosomes are separated in the first division, and sister chromatids are separated in the second division. Both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle. Both are believed to be present in the last eukaryotic common ancestor.
Prokaryotes (bacteria) undergo a vegetative cell division known as binary fission, where their genetic material is segregated equally into two daughter cells. All cell divisions, regardless of organism, are preceded by a single round of DNA replication.
For simple unicellular microorganisms such as the amoeba, one cell division is equivalent to reproduction – an entire new organism is created. On a larger scale, mitotic cell division can create progeny from multicellular organisms, such as plants that grow from cuttings. Mitotic cell division enables sexually reproducing organisms to develop from the one-celled zygote, which itself was produced by meiotic cell division from gametes. After growth, cell division by mitosis allows for continual construction and repair of the organism.[3] The human body experiences about 10 quadrillion cell divisions in a lifetime.[4]
The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information that is stored in chromosomes must be replicated, and the duplicated genome must be separated cleanly between cells.[5] A great deal of cellular infrastructure is involved in keeping genomic information consistent between generations.
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The big bang theory is states that <u>universe began as just a single point, then expanded and stretched to grow as large as it is </u><u>right</u><u> </u><u>now.</u>
<em><u>Hope</u></em><em><u> </u></em><em><u>this</u></em><em><u> helps</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em>
Most of the cells in the human body are diploid.
Diploid is a cell or organism that has paired chromosomes, one from each parent. In humans majority of the cells are diploid and have 23 pairs of chromosomes. The exception are the human sex cells (egg and sperm cells). These contain a single set of chromosomes and are known as haploid.
I believe high doses of stimulants can influence driving capabilities by inducing dizziness, panic reactions and hallucinations. Stimulants are substances that can affect a person's mood, often giving the user extra energy and a stronger sense of well-being. They can range from legal substances such as nicotine and caffeine to illegal drugs like cocaine and methamphetamine.
The southerly lowlands of the island average around 0 °C<span> (</span>32 °F) in winter, while the Highlands of Iceland tend to average around −10 °C<span> (14 °F). The lowest temperatures in the northern part of the island range from around −25 to −30 °C (−13 to −22 °F). The lowest temperature on record is −39.7 °C (−</span>39.5 °F<span>).</span>
