Question

PLEASE HELP I'M STUCK!

Which of the following best compares the roles of mitosis and meiosis in human reproduction?

Haploid sperm and egg nuclei fuse through meiosis, while the diploid zygote is formed through mitosis.

Haploid sperm nuclei are formed in the testes by meiosis, while the diploid zygote divides through mitosis.

The diploid nucleus in a zygote is formed by mitosis, while haploid gamete nuclei are formed by meiosis.

The diploid zygote nucleus divides through mitosis, while haploid gamete nuclei divide through meiosis.

Answer 1

Hint: mitosis keeps the number of chromosomes in the daughter cells the same whilst meiosis does not.

Answer 2

I don't mean to sound mean or anything, but this is due in 30 mins, and I really need the answer, I don't understand the question at all or the topic.

Answer 3

http://theodora.com/anatomy/the_ovum.html
figure

spermatogenesis - The long (~70 days) and complex process within the seminiferous tubules of the testes, in which an elaborate succession of distinct cell types are generated by mitotic and meiotic divisions; in the initial stage, diploid spermatogonia repeatedly divide by mitosis, giving rise to diploid primary spermatocytes, which in turn undergo the first meiotic division I, leading to haploid secondary spermatocytes; secondary spermatocytes undergo the second meiotic division II, leading to round spermatids, which elongate during the spermiogenesis process to form elongated spermatids and finally differentiate into mature spermatozoa, by condensation of the chromatin, with the substitution of histones with protamines in DNA supercoiling, and the formation of the acrosome, flagellum, and the other sperm organelles; the progression moves from the periphery to the center of the seminiferous tubule and is regulated by androgens; this process is regulated primarily by FSH from the anterior pituitary, but also by androgens from the testes themselves.

spermatogenesis - The long (~70 days) and complex process within the seminiferous tubules of the testes, in which an elaborate succession of distinct cell types are generated by mitotic and meiotic divisions; in the initial stage, diploid spermatogonia repeatedly divide by mitosis, giving rise to diploid primary spermatocytes, which in turn undergo the first meiotic division I, leading to haploid secondary spermatocytes; secondary spermatocytes undergo the second meiotic division II, leading to round spermatids, which elongate during the spermiogenesis process to form elongated spermatids and finally differentiate into mature spermatozoa, by condensation of the chromatin, with the substitution of histones with protamines in DNA supercoiling, and the formation of the acrosome, flagellum, and the other sperm organelles; the progression moves from the periphery to the center of the seminiferous tubule and is regulated by androgens; this process is regulated primarily by FSH from the anterior pituitary, but also by androgens from the testes themselves.

http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2020/2020%20Exam%20Reviews/Exam%205/CH27%20Spermatogenesis.htm

Answer 4

Mitosis

The male and female pronuclei don't fuse, although their genetic material do. Instead, their membranes dissolve, leaving no barriers between the male and female chromosomes. During this dissolution, a mitotic spindle forms between them. The spindle captures the chromosomes before they disperse in the egg cytoplasm. Upon subsequently undergoing mitosis (which includes pulling of chromatids towards centrioles in anaphase) the cell gathers genetic material from the male and female together. Thus, the first mitosis of the union of sperm and oocyte is the actual fusion of their chromosomes.[9]

Each of the two daughter cells resulting from that mitosis has one replica of each chromatid that was replicated in the previous stage. Thus, they are genetically identical.
http://en.wikipedia.org/wiki/Human_fertilization

Answer 5

http://theodora.com/anatomy/fertilization_of_the_ovum.html

Answer 6

Mitosis is the process by which the chromosomes in the nucleus of a cell are divided into into two new nuclei. This animation illustrates how the stages of mitosis progress and eventually lead to the formation of two new cells.

Mitosis is divide duplicated DNA of a cell into 2 new nuclei.
http://www.youtube.com/watch?v=C6hn3sA0ip0

Answer 7

Meiosis is a reduction division of a diploid nucleus(2n) to form a haploid nucleus (n).

Answer 8

2.5.6 State that growth, embryonic development, tissue repair and asexual reproduction involve mitosis(1).

State means to give a specific name, value or other brief answer without explanation or calculation.
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Growth: multicellular organisms increase their size through growth. This growth involves increasing the number of cells through mitosis. These cells will differentiate and specialise their function.

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Embryonic development is when the fertilised egg cell (zygote) divides to form the multicellular organism. Each cell in the organisms is identical (genetically) to all the other cells. However, each cell will express only a few of its genes to determine its overall specialisms, a process called differentiation. In this way a stem cell may becomes a muscle, or it may become a nerve cell or any one of the many different kinds of cells found in a complex multicellular organism. The best book about this process for the interested reader is

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Tissue Repair: As tissues are damaged they can recover through replacing damaged or dead cells. This is easily observed in a skin wound. More complex organ regeneration can occur in some species of amphibian.

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Asexual Reproduction: This the production of offspring from a single parent using mitosis. The offspring are therefore genetically identical to each other and to their “parent”- in other words they are clones. Asexual reproduction is very common in nature, and in addition we humans have developed some new, artificial methods. Bacteria DO NOT asexually reproduce by mitosis but rather by a process called Binary Fission.

http://click4biology.info/c4b/2/cell2.5.htm#stages

Answer 9

Mitosis is duplicate the number of cells while meosis is maintain the number of cell by producing gamete.