Concept:Each species has a fixed and characteristic number of chromosomes in its body cells.
Explanation:Chromosomes are thread-like structures found inside the nucleus of a cell.
Their number is constant for all members of the same species.
For example, human body cells have 46 chromosomes.
Chromosomes are not all the same shape; different chromosomes may differ in size and shape.
They are not neatly arranged in the cytoplasm, as they are confined within the nucleus.
Ribosomes are found on the rough endoplasmic reticulum, not on the outer membranes of chromosomes.
Therefore, the correct statement is that the chromosome number present in a species is constant.
Answer:B. the number present in a species is constant