Hi guys, could u plz help me? What would happen if there was no sun, and what would the Earth be like?

Dmitrij [34]

I haven't taken biology in a few years, so I may be wrong, but to me it looks like mitosis, since it only divides once, and if I can see the picture correctly it looks like each cell contains the same amount of chromosomes, but I can't see the picture very well. If it helps here are some differences between meiosis and mitosis:

1. Cell Division

Mitosis: A somatic cell divides once. Cytokinesis (the division of the cytoplasm) occurs at the end of telophase.

Meiosis: A reproductive cell divides twice. Cytokinesis happens at the end of telophase I and telophase II.

2. Daughter Cell Number

Mitosis: Two daughter cells are produced. Each cell is diploid containing the same number of chromosomes.

Meiosis: Four daughter cells are produced. Each cell is haploid containing one-half the number of chromosomes as the original cell.

3. Genetic Composition

Mitosis: The resulting daughter cells in mitosis are genetic clones (they are genetically identical). No recombination or crossing over occur.

Meiosis: The resulting daughter cells contain different combinations of genes. Genetic recombination occurs as a result of the random segregation of homologous chromosomes into different cells and by the process of crossing over (transfer of genes between homologous chromosomes).

4. Length of Prophase

Mitosis: During the first mitotic stage, known as prophase, chromatin condenses into discrete chromosomes, the nuclear envelope breaks down, and spindle fibers form at opposite poles of the cell. A cell spends less time in prophase of mitosis than a cell in prophase I of meiosis.

Meiosis: Prophase I consists of five stages and lasts longer than prophase of mitosis. The five stages of meiotic prophase I are leptotene, zygotene, pachytene, diplotene, and diakinesis. These five stages do not occur in mitosis. Genetic recombination and crossing over take place during prophase I.

5. Tetrad Formation

Mitosis: Tetrad formation does not occur.

Meiosis: In prophase I, pairs of homologous chromosomes line up closely together forming what is called a tetrad. A tetrad consists of four chromatids (two sets of sister chromatids).

6. Chromosome Alignment in Metaphase

Mitosis: Sister chromatids (duplicated chromosome comprised of two identical chromosomes connected at the centromere region) align at the metaphase plate (a plane that is equally distant from the two cell poles).

Meiosis: Tetrads (homologous chromosome pairs) align at the metaphase plate in metaphase I.

7. Chromosome Separation

Mitosis: During anaphase, sister chromatids separate and begin migrating centromere first toward opposite poles of the cell. A separated sister chromatid becomes known as daughter chromosome and is considered a full chromosome.

Meiosis: Homologous chromosomes migrate toward opposite poles of the cell during anaphase I. Sister chromatids do not separate in anaphase I.

I can add the similarities between them if you need. This work is not mine, I got it from thoughtCo.

Good luck :)

3 0

3 years ago

Select all that apply tomitosis (Choose 4)

mamaluj [8]

Select all that apply

8 0

3 years ago

Please help fast...please

RSB [31]

Answer:

Radioactive

Explanation:

hope this helped! :)

5 0

3 years ago

Compare and contrast the concepts of average mass and relative mass

Sphinxa [80]

Answer:

Relative and average atomic mass both describe properties of an element related to its different isotopes. However, relative atomic mass is a standardized number that's assumed to be correct under most circumstances, while average atomic mass is only true for a specific sample.

Explanation:

6 0

4 years ago

From the standpoint of entropy, consider the following processes: water boiling, mixing cola and root beer sodas, and assembling

Triss [41]

Answer:

b) Water boiling and mixing cola and root beer sodas are favorable processes, but assembling a house of cards is not.

Explanation:

Entropy, a measure of a system's thermal energy per unit of temperature that cannot be used to do work. Work, is obtained from directed motion of molecules, it follows the the amount of entropy is a measure of the molecular randomness, or disorder, of the system. As such increased entropy increases randomness hence water boiling and mixing cola and root beer sodas are favorable processes, but assembling a house of cards which requires a great deal of effort is not.

7 0

3 years ago