Lec. 19 - Cell Cycle and Cell Division

Question 1

Differentiate btwn. binary fission, mitosis, and meiosis.

Answer 1

Binary fission is a method of reproduction in single celled organisms, allowing them to replicate and divide to produce two identical daughter cells. Mitosis is essential for growth and repair and asexual reproduction in some organisms, resulting in the production of two identical diploid daughter cells. Meiosis’ primary function is to produce gametes with half the chromosome number of the parent cell, ensuring genetic diversity.

Question 2

Compare asexual and sexual reproduction.

Answer 2

Asexual reproduction involves the creation of offspring from a single parent, without the involvement of gametes. Sexual reproduction involves the fusion of gametes from two parents to form diverse offspring.

Question 3

Explain the cell cycle stages.

Answer 3

Interphase, G1 phase, S phase, G2 phase, mitotic phase, prophase, metaphase, anaphase, telophase, cytokinesis.

Question 4

Describe the stages of mitosis.

Answer 4

Prophase, which involves chromatic condensation, nuclear envelope breakdown and spindle formation, the metaphase which includes chromosomal alignment and spindle fiber attachment, then anaphase, which includes sister chromatid separation, telophase, which has spindle disassembly and cytokinesis initiation.

Question 5

Describe what is meant by haploid and diploid and the relation to cell division.

Answer 5

Haploid and diploid refer to the number of sets of chromosomes present in a cell. Haploids are found in gametes, diploids are found in most somatic cells.

Question 6

Explain the process of cytokinesis and how this occurs in plant and animal cells.

Answer 6

Cytokinesis is the final stage of the cell cycle that involves the division of the cytoplasm to form two daughter cells. In animal cells, it involves the formation of a contractile ring made of actin and myosin proteins. In plant cells the process involves the formation of a cell plate.

Question 7

Explain why there are checkpoints in the cell cycle.

Answer 7

There are checkpoints that serve as control points that regulate and ensure the accurate progression of the cell cycle stages.