Biology, 17.02.2020 16:59 datbih12345

In an organism with a diploid number of 2n=10, how many individual chromosomal structures will align on the metaphase plate during (a) mitosis, (b) meiosis I and (c) meiosis II.

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Answer from: moneykey

The correct answer is (a) Mitosis = 10, (b) Meiosis I = 10, (c) Meiosis II = 5.

Explanation:

Mitosis is the process by which the genetic material from the parent cell is divided equally among the daughter cells. This process of mitosis is preceded the a replication phase where the genetic material of the parent cell is doubled and then divided among the daughter cells. The ploidy or the chromosome number of the parent is maintained in the daughter cell.Meiosis is the process by which the genetic material from the parent cell is divided among daughter cells, where the daughter cells are the gametes. Here, the number of chromosomes in the daughter cells is half of that present in the parent cell.A diploid individual having 10 chromosomes, have 5 of the chromosomes obtained from its mother and 5 from its father.During mitosis, each of the 10 chromosomes will be divided between the two daughter cells. This is done by replication or doubling of the 10 chromosomes. This replication process will result in the generation of 2 chromatids per chromosome. During the metaphase stage of mitosis when these chromosomes align along the metaphase plate, there will be 10 chromosomes aligning and each chromosome will comprise of 2 chromatids, so total there will be 20 chromatids. These chromatids separate during the anaphase and generate 20 chromosomes in the dividing parent cell.In the metaphase stage of meiosis I, the homologous (each obtained from mother and father) pair of chromosomes arrange themselves in tetrad or bivalents (two chromosomes together). Therefore, if the total number of chromosome is 10, there are 5 bivalents that can be formed from them. However, the total number of chromosomes that align along the metaphase plate is 10. Each chromosome has 2 chromatids, so total number of chromatids is 20. During anaphase I phase, the bivalents or homologous chromosomes separate from each other, and the number of chromosomes and chromatids in each daughter cell after meiosis I is 5 and 10 respectively.The metaphase stage of meiosis II is exactly same as that of mitosis. Here the 5 chromosomes comprising of 10 chromatids, obtained after meiosis I, are aligned along the metaphase plate. During anaphase II, the 10 chromatids are further divided into the two gametes such that each gamete gets 5 chromosomes (after separation chromatid forms the chromosome).

Answer from: Quest

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Answer from: Quest

question#1

ans:

cell is the basic unit of organization of all living things. cells are often called the building block of life and it is the smallest unit of life. the study of cell is called cell biology. cell consists of cytoplasm enclosed within membrane, which contain bio-molecules such as proteins and nucleic acid.

two third of cell is water, which means that two-third of your whole body is water. the rest is the mixture of molecules, mainly proteins, lipids and carbohydrates.

question#2

ans:

organ:

an organ is a group of tissues specialized to form a functional unit. an example is the heart in animals.

organ system:

an organ system is a group of several organs whose functions are synchronized to release an effective action in a living organism. an example is digestive system.

question#3

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#4

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#5

our body works because of the interactions that happen between organs and organ systems.

for example:

the heart to regulate blood flow throughout the body. the blood carries oxygen and nutrients to the cells and carries carbon dioxide and waste away from the cells. body systems work together in maintaining a constant internal environment. when this balance is disrupted, the body systems may not function properly, and human health can suffer. you start to feel bad.