Immune tolerance is the lack of capacity to increase the reaction to antigens. The tolerance can either be natural or “self” tolerance. On the other hand, licensing is a kind of protein that lets replication for cells. They usually happen with eukaryotic cells and they begin with the replication of DNA.
Answer: C. Homologous chromosomes are separated in meiosis but not in mitosis.
Explanation: There are two main types of division that take place in eukaryotic cells, mitosis, and meiosis. Mitosis is the type of division that is used for growth, repair, and replacement of tissues. Therefore it is not necessary that the cells have different chromosome numbers or are varied genetically in the daughter cells in the case of mitosis.
Meiosis is the division that takes place to form the gametes for sexual reproduction. It is important in the first stages of meiosis I, to introduce variation and to halve the chromosome number.
Chromosomes numbers are halved (from 46 to 23) during meiosis I because the gametes (sperm and egg) come together and fuse during fertilization to form a zygote. When this fusion occurs (23 from the zygote and 23 from the egg), the chromosome number needs to be returned to that of the parent cell (46).
At the end of meiosis, four genetically unique cells are produced with half the number of chromosomes as the parent cell (23 cromosomes) . After the process of mitosis is completed, two cells genetically identical to each pther are produced and have the same number of chromosomes as the parent cell (46 cromosomes).
Genetic variation is actually important because of changing environmental conditions.
The answer is d............
b. a large soft egg
c. an egg with an amnion
B. Contain DNA
C. Surround the cell
D. Helps make proteins
5. Which of the following is a function of a vacuole?
A. Packaging of materials
B. Transport of materials
C. Storage of materials
D. Breakdown of materials
A function of the cytoskeleton is - A. Helps a cell keep its shape and a function of a vacuole - C. Storage of materials.
Cytoskeleton
Vacuole:
Thus, A function of the cytoskeleton is - A. Helps a cell keep its shape and a function of a vacuole - C. Storage of materials.
Learn more about vacuoles:
Answer:
Genetic drift reduces the size of gene pool of the population.
Explanation:
Genetic drift is any chance event that results in changes in the allele frequency of a population. The event either fixes an allele on the particular locus or makes the population to lose that allele.
Hence, genetic drift changes the genetic frequency by removal of a particular allele or by fixing it in the gene pool. Both conditions lead to reduced genetic variations in the population. And since genetic drift reduces the size of the population, the gene pool of the population would also shrink due to loss of alleles from it.