Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
Answer:
There are four categories for air masses: arctic, tropical, polar and equatorial. Arctic air masses form in the Arctic region and are very cold.
Answer:
C Phloem transports glucose to the plant, and stomata release oxygen
Explanation:
A Stomata take in water,sunlight, and carbon dioxide and release oxygen - this is false, the stomata are for gas exchange (taking in carbon dioxide and releasing oxygen). They do not take in water and sunlight
B Phloem transports water, stomata take in carbon dioxide, and chlorophyll absorbs sunlight - this is false, while it is true that stomata take in carbon dioxide, and chlorophyll absorbs sunlight. phloem does not transport water, that is the xylem.
C Phloem transports glucose to the plant, and stomata release oxygen - this is true. Stomata takes in carbon dioxide and releases oxygen, and phloem transport the products of photosynthesis throughout the plant
D Xylem takes in water, sunlight and carbon dioxide and releases oxygen - this is false. Xylem does take in water, but not sunlight, carbon dioxide or oxygen
The condition common to protozoa whereby the cell of the organism acts as a gamete is isogamy. It is <span>a condition in which the sexual cells, or gametes, are of the same form and size and are usually indistinguishable from each other. Hope this answers the question.</span>
