Answer:
(a) crossing over: Meiosis I, Recombination
(b) chromatids separate at their centromeres and migrate to opposite poles: Meiosis II, Anaphase II
(c) chromosomes become aligned in pairs at the equator: Meiosis II, Metaphase II
Explanation:
Homologous recombination is a type of genetic recombination that occurs during meiosis (formation of ovum and sperm cells). The paired chromosomes of the male and female parents are aligned so that similar DNA sequences intersect. This crossing over produces an exchange of genetic material, which is an important cause of the genetic variability observed in the offspring.
Meiosis II: Anaphase II. The centromeres separate and the daughter chromatids - now individual chromosomes - move to the opposite poles of the cell. The centromeres separate, and the two chromatids of each chromosome move toward the opposite poles in the spindle.
Meiosis II: Metaphase II. Chromosomes are accommodated in the equatorial plate of metaphase, similar to what happens in mitosis. They are attached to the already fully formed meiotic spindle. Each chromosome is aligned in the equatorial plate of the metaphase, as it happens in mitosis.
A person can only show a recessive trait if both of their parents carried at least one copy of each of the recessive allele. The parents do not need to show the trait, as one copy is not enough to reveal it, but they must both carry it.
Hope this helped!
I may be wrong but maybe oil
Answer:
Thymine= 60 ng
Guanine= 20 ng
The complementary base pairing occurs between adenine and thymine and guanine and cytosine bases.
Explanation:
According to the Chargaff rule, a double-helical DNA molecule has an equal number or equal amount of adenine and thymine bases since adenine always pairs with thymine. Similarly, the amount of guanine base is equal to that of the cytosine base.
Chargaff rule is based on the complementary base pairing between purine and pyrimidine bases. According to the given information, the amount of adenine is 60 ng. Therefore, the cell would have 60 ng thymine. Similarly, the amount of the cytosine base in the cell is 20 ng which means that the cell would have 20 ng of guanine base.
Answer:
from top to bottom
Explanation:
North pole, northern hemisphere, equator, southern hemisphere, south pole.