15675.Exchange of paternal and maternal chromosome material during cell division is
Crossing over
Bivalent formation
Dyad formation
Synapsis
15676.Which stages of cell division do the following figures A and B represent respectively?
Prophase - Anaphase
Metaphase - Telophase
Telophase - Metaphase
Late Anaphase - Prophase
15677.Synapsis occurs between
mRNA and ribosomes
A male and a female gamete
Two homologous chromosomes
Spindle fibres and centromere
15678.During gamete formation, the enzyme recombinase participates during
Prophase-I
Prophase-II
Metaphase-I
Anaphase-II
15679.A change in the amount of yolk and its distribution in the egg will affect:
Fertilization
Formation of zygote
Pattern of cleavage
Number of blastomeres produced
15684.A bivalent consists of
Two chromatids and one centromere
Four chromatids and two centromeres
Two chromatids and two centromeres
Four chromatids and four centromeres
15685.Which of the following cellular structures always disappears during mitosis and meiosis?
Plasma membrane
Nucleolus and nuclear envelope
Plastids
none of these
15686.If you are provided with root-tips of onion in your class and are asked to count the chromosomes which of the following stages can you most conveniently look into:
Prophase
Anaphase
Telophase
Metaphase
15688.In humans, at the end of the first meiotic division, the male germ cells differentiate into the:
Spermatogonia
Primary spermatocytes
Secondary spermatocytes
Spermatids
15689.Cell division can not be stopped in which phase of the cell cycle?
G1-phase
G2-phase
S-phase
Prophase
15690.Given below is a schematic break-up of the phases/stages of cell cycle. Which one of the following is the correct indication of the stage/phase in the cell cycle?
A-Cytokinesis
B-Metaphase
C-Karyokinesis
D-Synthetic phase
15692.During oogenesis the cell that is fertilized by a sperm to become an egg is
primary spermatocyte
secondary oocyte
primary oocyte
secondary spermatocyte
15694.During which stage the chromosomes first become visible.
Anaphase
Metaphase
Prophase
Telophase