At metaphase of mitosis, each chromosome consists of _______ chromatid(s) _______ centromere(s) ________ kinetochore(s) and _______ molecules of DNA:

(1) 2, 1, 2, 2        

(2) 2, 2, 2, 2       

(3) 2, 1, 1, 1                  

(4) 2, 1, 2, 1

In prophase mitosis, which one of the following events occurs in animal cells but not in plant cells?

(1) Centrioles migrate to opposite sides of the nucleus

(2) Homologous chromosomes do not associate

(3) The nuclear envelope (membrane) breaks down

(4) Nucleoli disappear

Synaptonemal complex is more conspicious at:

(1) Zygotene        

(2) Pachytene      

(3) Diplotene         

(4) Leptotene

Cellular structures which disappear during late prophase and reappear during telophase are:

(1) Mitochondria and spindle fibres   

(2) Plasma membrane

(3) Nuclear membrane and nucleolus 

(4) Plastid

A picture of dividing Drosophila cell through a microscope shows that the cell contains 8 chromosomes, each consisting of two chromatids. The picture must have been taken during:

(1) Mitotic metaphase                       

(2) Mitotic Anaphase

(3) Meiotic Anaphase II                     

(4) Meiotic Telophase II

Cytokinesis in animal cell takes place by _______; in _______ direction while in plant cell by _______; in _______ direction:

(1) Furrowing, centrifugal, cell plate, centripetal

(2) Furrowing, centripetal, cell plate, Centrifugal

(3) Cell plate, centrifugal, furrowing, centripetal

(4) Cell plate, centripetal, furrowing, centrifugal

Liquid endosperm in coconut is resulted due to:

(1) Karyokinesis followed by cytokinesis

(2) Failure of karyokinesis followed by cytokinesis

(3) Karyokinesis twice followed by single cytokinesis

(4) Karyokinesis is not followed by cytokinesis

The above graph shows the change in DNA content during various phases (A to (d) in a typical mitotic cell cycle. Identify the phases:

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?
A. Diploid cells found in the Go or G1 phase.
B. Cells with twice the normal DNA content in the early M phase.
C. Cells with intermediate amounts of DNA in the S Phase.
D. Cells with twice the normal DNA content in the G2 phase.
(a) A and B               (b) B and C             (c) C and D              (d) All are correct