Correct answer is B.
Explanation:
In their nucleus cells contain DNA. The DNA has information about size, shape and function of each cell. When the cell reaches it's full size it stops growing and starts doing whatever it's function is. If more cells are needed then the cell replicates. This explanation excludes answers A and C.
Male and female sexual cells are used to conceive a baby. These cells combine to form a new type of cells. In the first few weeks all types of cells are created. Then the creation of new types of cells stops and existing cells multiply in order to achieve needed number of cells. This explanation excludes answer D.
When we compare an adult person and a baby we can see that, for example, an adult has bigger bones than a baby. This was result of increasing number of existing types of cells without creating any new type.
Answer:
Events which occur in chemical reactions like photosynthesis are extremely fast.
Explanation:
To see what happens in reactions such as photosynthesis, scientists need advanced cameras that can capture ultra-fast motions occurring within extremely short scales of time.
Doldrums are caused by solar radiation from the sun. Because of this the sunlight beams warms the air and causes it to rise straight up instead of side to side (horizontally).
PRECIPITATION,TEMPERATURE, VEGETATION
I would believe the answer to be B. <span />
