Answer:
This shows the interaction between the earth and sun.
Explanation:
- There is a variation in the amount of heat that reaches the different latitudes as the interaction between the sun and earth which firms different angles of incidence on the surface.
- The rays of the sun are more concentrated in mid latitudes that is the tropics and are slanting towards the poles this due the tilt in axis of earth.
- This variation lads the warm air to rise and reach the poles and similar the cold polar air reaches the tropics and develops a cycle of convective cells. This leads to a latitudinal balance in temperatures.
<span>If a scientist is trying to determine whether the use of cell phone contributes to brain cancer, then the most significant weakness in this type of study is the relationship between the cell phone and brain cancer itself. It is hard to identify its connections and consequences with each other.</span>
Answer:
30
Explanation:
The seed of an angiosperm is formed as a result of fertilization (fusion of sperm in pollens and the ova from ovary). According to the question, the cells of the seed which will grow into the plant contains 20 chromosomes. Seeds of angiosperms contain a tissue called ENDOSPERM that forms as a result of the unique DOUBLE FERTILIZATION in angiosperms. It occurs when one haploid sperm cell fuses with two haploid polar nuclei to form a triploid endospermic structure that serves as food for the growing embryo in the seed.
Now based on the above explanation, the diploid plant cell with 20 chromosomes will have 10 chromosomes (half as much) in its gametes as a result of meiosis. This 10 chromosomes in each gamete (sperm and ovum) fuses to form a diploid zygote with 20 chromosomes, while one haploid sperm cell (10 chromosomes) also fuses with two haploid polar nuclei (10 chromosomes each) to form a triploid endosperm with 30 chromosomes i.e. 10+10+10.
Acid fast stain is used to stain the bacteria of the genus Mycobacteria, because they contain large amounts of impermeable wax-like sbstances, which do not allow gram stain to penetrate the cells. Gram stain however, can penetrate the other bacteria with varying amounts of polysaccharides and lipopolysaccharadies in their cell walls, and thus can differentiate between them, For Acid fast stain, it would be difficult to differentiate between the gram positive and negative cells, and therefore, it is not used for this differential purpose, but to identify the Mycobacterim only.
