A reduction step during meiosis is important because:

1.	It returns the chromosome number to normal before fertilization
2.	There is a mechanism for this
3.	Only one copy of each chromosome is necessary
4.	Otherwise chromosome copies would double each fertilization

The DNA content of individual cells and the number of cells in each phase of a "cell cycle" can be determined, using flow cytometry. Which of the following combinations of "phase of a cell cycle and its corresponding DNA content" can be considered normal?

1. A and B
2. B and C
3. C and D
4. All are correct

The following diagram refers to a typical cell cycle.

Identify the parts marked as X, Y and Z.

Identify the meiotic stage in which the homologous chromosomes separate while the sister chromatids remain associated at their centromeres:

(1) Metaphase I    

(2) Metaphase II  

(3) Anaphase I     

(4) Anaphase II

Select the correct statement about G₁ phase:

(1) Cell is metabolically inactive

(2) DNA in the cell does not replicate

(3) It is not a phase of synthesis of macromolecules

(4) Cell stops growing

Which of the following is a continuous process?

Cell growth is a continuous process in terms of

The process of distribution of duplicated DNA in the daughter cells is

The division time for human cell is

The inter phase in human cell cycle lasts for