<span>The embryonic period is the most important phase of development for organ formation. The embryonic period in humans begins at the moment of fertilization and continues until the end of the tenth week of gestation. Rapid growth and differentiation occurs during this period, which produces varied cell types.</span>
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.
Answer:
The climate in the area gets warmer.
Answer:
Green plants are responsible for oxygen in the atmosphere.
Explanation:
-Green plants undertake a process of photosynthesis, in which they use energy from the sun, carbon dioxide and water to form simple sugars and also release oxygen to the atmosphere. The simple sugars from the process may be used by the cells for energy or be stored in form of energy for future use.
-Oxygen is a product of photosynthesis which is released to the atmosphere.
