B. some species die out when environmental changes occur
Answer:
The correct answer will be option- D.
Explanation:
The prostate gland is a walnut-shaped gland present between the bladder and penis.
The prostate gland is a part of the reproductive system and not the urinary system as it helps in the nourishment and protection of the sperm cells. It secretes a fluid which contains enzymes like phosphatases, lytic enzymes and antibiotics which helps in the protection and passage of sperm to the egg cell.
Thus, option- D is the correct answer.
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 volcanic winter is a reduction in global temperatures caused by volcanic ash and droplets of sulfuric acid and water obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, particularly explosive volcanic eruption.
True
DNA are cells that carry genetic codes and are passed down through generations of offspring. New cells can only arise from existing cells!
