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I'm just doing a project for school and I'm not sure what they are. Please help?

2007-01-09 12:37:42 · 6 answers · asked by falloutgirl349 1 in Science & Mathematics Biology

6 answers

Mitosis is simple cell division, ending up with two identical cells, each with both pairs of every gene.

Meiosis is cell division for gametes (sex cells). This is a two step process, and the four cells that remain each have half the normal cells, so that when the gametes fuse at conception, there will be a new organization of DNA, from both parents.

2007-01-09 12:46:40 · answer #1 · answered by John T 6 · 38 3

Difference Between Mitosis And Meiosis

2016-12-08 15:50:18 · answer #2 · answered by Anonymous · 0 0

Meiosis Vs Mitosis

2016-09-29 23:42:14 · answer #3 · answered by ? 4 · 0 0

Cells divide and reproduce in two ways: mitosis and meiosis. Mitosis is a process of cell division that results in two genetically identical daughter cells developing from a single parent cell. Meiosis, on the other hand, is the division of a germ cell involving two fissions of the nucleus and giving rise to four gametes, or sex cells, each possessing half the number of chromosomesof the original cell.
Mitosis is used by single-celled organisms to reproduce; it is also used for the organic growth of tissues, fibers, and membranes. Meiosis is found in sexual reproduction of organisms. The male and female sex cells (i.e., egg and sperm) combine to create new, genetically different offspring.

2014-08-07 22:53:01 · answer #4 · answered by jhenny ann 1 · 4 0

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I can say that there is an ocean of a difference between solitude and loneliness Solitude is your own conscious choice to be alone,irrespective of whether you have a galaxy of friends or not.When you're in solitude, you dont crave or think about others Every human being needs solitude, the time which he can spend for himself/herself, the time when he feels he is at peace Loneliness is something that you have no choice, you're alone because you dont have others to be with you Shy people for example are often victims of loneliness.On the other hand there are people whose interest in something make them get withdrawn from the social life ,for example scientists, artists.Ofcourse many who are lonely end up seeking solitude Loneliness is a state of the mind, you can be with thousand people yet feel,so secluded,isolated and different from the rest Loneliness affects your mind, solitude doesnt

2016-03-25 21:24:41 · answer #5 · answered by Anonymous · 0 1

Mitosis is the nuclear division producing two daughter nuclei identical to the original nucleus. A type of nuclear division that produces two daughter nuclei identical to the parent nucleus normally just prior to cell division.
Ie, a cell dividing to form two cells, which are clones of one another.
Meiosis is Two successive nuclear divisions (with corresponding cell divisions) that produce haploid gametes (in animals) or haploid sexual spores (in plants and fungi) having one-half of the genetic material of the original cell. The nuclear and cell division process in diploid eukaryotes that results in four haploid gametes or spores having one member of each original pair of homologous chromosomes only per nucleus.
1 cell, dividing into 2 then into 4, and have genetic variation. Sexual reproduction.

2007-01-09 12:47:04 · answer #6 · answered by Becky F 1 · 12 0

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RE:
What are the differences between Mitosis and Meiosis?
I'm just doing a project for school and I'm not sure what they are. Please help?

2015-08-18 19:59:13 · answer #7 · answered by Anonymous · 1 1

Mitosis: -produces more offspring
- Produces 2 cells
- Resulting cells are genitically identical
- No crossing over or homologous pairs
- Includes one nuclear division
- Has diploid cells(all cells 46)

Meiosis: - Produce fewer offspring
- Produces 4 cells
- Includes 2 nuclear divisions
- Resulting cells not genitically identical
- Includes pairing of homologous chromosomes and crossing over
- Includes haploid cells (half 23)

2007-01-09 12:58:01 · answer #8 · answered by nilo 3 · 46 0

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2014-03-25 11:59:52 · answer #9 · answered by Brian Toussaint 1 · 1 14

Mitosis is the process by which a cell separates its duplicated genome into two identical halves. It is generally followed immediately by cytokinesis which divides the cytoplasm and cell membrane. This results in two identical daughter cells with a roughly equal distribution of organelles and other cellular components. Mitosis and cytokinesis together is defined as the mitotic (M) phase of the cell cycle, the division of the mother cell into two daughter cells, each the genetic equivalent of the parent cell. Mitosis occurs exclusively in eukaryotic cells. In multicellular organisms, the somatic cells undergo mitosis, while germ cells — cells destined to become sperm in males or ova in females — divide by a related process called meiosis. Prokaryotic cells, which lack a nucleus, divide by a process called binary fission.

The process of mitosis is complex and highly regulated. The sequence of events is divided into phases, corresponding to the completion of one set of activities and the start of the next. These stages are prophase, prometaphase, metaphase, telophase and anaphase. During the process of mitosis the pairs of chromosomes condense and attach to fibers that pull the sister chromatids to opposite sides of the cell. The cell then divides in cytokinesis, to produce two identical daughter cells.

Because cytokinesis usually occurs in conjunction with mitosis, "mitosis" is often used interchangeably with "mitotic phase". However, there are many cells where mitosis and cytokinesis occur separately, forming single cells with multiple nuclei. This occurs most notably among the fungi and slime moulds, but is found in various different groups. Even in animals, cytokinesis and mitosis may occur independently, for instance during certain stages of fruit fly embryonic development.[1] Errors in mitosis can either kill a cell through apoptosis or cause mutations that may lead to cancerThe primary result of mitosis is the division of the parent cell's genome into two daughter cells. The genome is composed of a number of chromosomes, complexes of tightly-coiled DNA that contain genetic information vital for proper cell function. Because each resultant daughter cell should be genetically identical to the parent cell, the parent cell must make a copy of each chromosome before mitosis. This occurs during the middle of interphase, the period that precedes the mitotic phase in the cell cycle where preparation for mitosis occurs.[2]

Each chromosome now contains two identical copies of itself, called sister chromatids, attached together in a specialized region of the chromosome known as the centromere. Each sister chromatid is not considered a chromosome in itself, and a chromosome does not always contain two sister chromatids.

In eukaryotes, the nuclear envelope that separates the DNA from the cytoplasm degrades, and its fluid spills out into the cytoplasm. The chromosomes align themselves in a line spanning the cell. Microtubules, essentially miniature strings, splay out from opposite ends of the cell and shorten, pulling apart the sister chromatids of each chromosome.[3] As a matter of convention, each sister chromatid is now considered a chromosome, so they are renamed to sister chromosomes. As the cell elongates, corresponding sister chromosomes are pulled toward opposite ends. A new nuclear envelope forms around the separated sister chromosomes.

As mitosis completes cytokinesis is well underway. In animal cells, the cell pinches inward where the imaginary line used to be, separating the two developing nuclei. In plant cells, the daughter cells will construct a new dividing cell wall between each other. Eventually, the mother cell will be split in half, giving rise to two daughter cells, each with an equivalent and complete copy of the original genome.

Prokaryotic cells undergo a process similar to mitosis called binary fission. However, prokaryotes cannot be properly said to undergo mitosis because they lack a nucleus and only have a single chromosome with no centromere.[4]In biology, meiosis is the process that allows one diploid cell to divide in a special way to generate haploid cells in eukaryotes. The word "meiosis" comes from the Greek meioun, meaning "to make smaller," since it results in a reduction in chromosome number.

Meiosis is essential for sex. It therefore occurs in most eukaryotes, including single-celled organisms. A few eukaryotes, notably the Bdelloid rotifers, have lost the ability to carry out meiosis and acquired the ability to reproduce by parthenogenesis. Meiosis does not occur in archaea or prokaryotes, which reproduce by asexual cell division processes.

During meiosis, the genome of a diploid germ cell, which is composed of long segments of DNA called chromosomes, undergoes DNA replication followed by two rounds of division, resulting in haploid cells called gametes. Each gamete contains one complete set of chromosomes, or half of the genetic content of the original cell. These resultant haploid cells can fuse with other haploid cells of the opposite gender or mating type during fertilization to create a new diploid cell, or zygote. Thus, the division mechanism of meiosis is a reciprocal process to the joining of two genomes that occurs at fertilization. Because the chromosomes of each parent undergo genetic recombination during meiosis, each gamete, and thus each zygote, will have a unique genetic blueprint encoded in its DNA. In other words, meiosis is the process that produces genetic variation.

Biochemically, meiosis uses some of the same mechanisms employed during mitosis to accomplish the redistribution of chromosomes. There are several features unique to meiosis, most importantly the pairing and recombination between homologous chromosomes, which enable them to separate from each other.Meiosis occurs in all eukaryotic life cycles involving sexual reproduction, comprising of the constant cyclical process of meiosis and fertilization. This takes place alongside normal mitotic cell division. In multicellular organisms, there is an intermediary step between the diploid and haploid transition where the organism grows. The organism will then produce the germ cells that continue in the life cycle. The rest of the cells, called somatic cells, function within the organism and will die with it. to trace a trait through generations of a family, you can use a pedigree The organism phase of the life cycle can occur between the haploid to diploid transition or the diploid to haploid transition. Some species are diploid, grown from a diploid cell called the zygote. Others are haploid instead, spawned by the proliferation and differentiation of a single haploid cell called the gamete. Humans, for example, are diploid creatures. Human stem cells undergo meiosis to create haploid gametes, which are sperm cells for males or ova for females. These gametes then fertilize in the Fallopian tubes of the female, producing a diploid zygote. The zygote undergoes progressive stages of mitosis and differentiation, turns into a blastocyst and then gets implanted in the uterus endometrium to create an embryo.

There are three types of life cycles that utilise sexual reproduction, differentiated by the location of the organisms stage.

In the gametic life cycle, of which humans are a part, the living organism is diploid in nature. Here, we will generalize the example of human reproduction stated previously. The organism's diploid germ-line stem cells undergo meiosis to create haploid gametes, which fertilize to form the zygote. The diploid zygote undergoes repeated cellular division by mitosis to grow into the organism. Mitosis is a related process to meiosis that creates two cells that are genetically identical to the parent cell. The general principle is that mitosis creates somatic cells and meiosis creates germ cells.

In the zygotic life cycle, the living organism is haploid. Two organisms of opposing gender contribute their haploid germ cells to form a diploid zygote. The zygote undergoes meiosis immediately, creating four haploid cells. These cells undergo mitosis to create the organism. Many fungi and many protozoa are members of the zygotic life cycle.

Finally, in the sporic life cycle, the living organism alternates between haploid and diploid states. Consequently, this cycle is also known as the alternation of generations. The diploid organism's germ-line cells undergo meiosis to produce gametes. The gametes proliferate by mitosis, growing into a haploid organism. The haploid organism's germ cells then combine with another haploid organism's cells, creating the zygote. The zygote undergoes repeated mitosis and differentiation to become the diploid organism again. The sporic life cycle can be considered a fusion of the gametic and zygotic life cycles, and indeed its diagram supports this conclusion.


[edit] Process
Because meiosis is a "one-way" process, it cannot be said to engage in a cell cycle as mitosis does. However, the preparatory steps that lead up to meiosis are identical in pattern and name to the interphase of the mitotic cell cycle.

Interphase is divided into three phases:

Gap 1 (G1) phase: Characterized by increase in cell size due to accelerated manufacture of organelles, proteins, and other cellular matter.
Synthesis (S) phase: The genetic material is replicated: each of its chromosomes duplicates. The cell can thereby be said to be currently tetraploid.
Gap 2 (G2) phase: The cell continues to grow.

2007-01-09 13:11:41 · answer #10 · answered by wierdos!!! 4 · 6 18

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