Bacterium divides every 35 minutes. If a culture containing 105 cells per mL is grown for 175 minutes, what will be the cell concentration per mL after 175 minutes?
1. 5 x 105 cells
2. 35 x 105 cells
3. 32 x 105 cells
4. 174 x 105 cells
During cell division, the spindle fibres attach to the chromosomes at a region called
1. chromocentre
2. kinetochore
3. centriole
4. chromomere
What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its roots tip cells?
1. 21
2. 42
3. 63
4. 84
Synapsis occurs between
1. a male and a female gamete
2. mRNA and ribosomes
3. spindle fibres and centromere
4. two homologous chromosomes
Best stage to observe shape, size and number of chromosomes is
1. interphase
2. metaphase
3. prophase
4. telophase
If a diploid cell is treated with colchicine then it becomes.
1. triploid
2. tetraploid
3. diploid
4. monoploid
Which one of the following precedes reformation of the nuclear envelope during M-phase of the cell cycle?
1. Decondensation from chromosomes and reassembly of the nuclear lamina
2. Transcription from chromosomes and reassembly of the nuclear lamina
3. Formation of the contractile ring and formation of the phragmoplast
4. Formation of the contractile ring and transcription from chromosomes.
During mitosis ER and nucleolus begin to disappear at.
1. late prophase
2. early metaphase
3. late metaphase
4. early prophase
A bivalent consists of
1. two chromatids and one centromere
2. two chromatids and two centromeres
3. four chromatids and two centromeres
4. four chromatids and four centromeres
Meiosis has evolutionary significance because it results in
1. genetically similar daughters
2. four daughter cells
3. eggs and sperms
4. recombinations