Biology - Cell replication

[Kombmail]

Hiyeeeeeeee!!!!!!
I was wandering if a lecturer could look at my following answers to the given questions:

Q1. Explain the difference between a chromatid and a chromosome.
Chromosomes contain all or most of the genes in the organism, are used throughout the stages of nuclear division and are located consistently throughout the nuclei of eukaryotes.

In contrast to chromosomes, chromatids are counted as chromosomes, and possess the same information, however they are replicated structures of chromosomes held together by centromeres. They are only visible during mitosis.

Q2. Distinguish between cell division and mitosis.

Cell division or nuclear division, is the division of the cell ( animal or plant) including stages of early prophase, mitosis ( includes prophase, metaphase and anaphase), telophase and cytokinesis.

In early prophase, DNA synthesis occurs resulting in a 'chromatin' as the process of replication is completed. Mitosis, is a three - stage process included in cell division, in which chromosomes condense, the spindle apparatus forms, chromosomes align to the equator and as a result ( in its last stage anaphase), form sister chromatids seperated to opposite poles of the cell. Telophase is the stage where nuclear membranes assemble around the two daughter nuclei seperate into two daughter cells ( prokaryotes and eukaryotes).

Q4.
(a) Describe the main difference between unicellular and multicellular organisms with respect to the role of mitotic cell division.

In unicellular organisms, mitotic cell division occurs for asexual reproduction and in multicellular organisms occurs for growth and repair functioning.

(b) State two other important roles of mitosis in multicellular organisms.

Mitosis is important in order to provide equally distributed genetic information from the parent cell to the offspring in its DNA. The number of chromosomes being equal is vital to the offspring in order for it to grow individually and healthy enough to produce its own offspring in the future. It is very important for mitosis to be successful in reference to telomeres. Telomeres are ending structures on chromosomes which already have lifespans of their own as the organism ages. If there is an unsuccessful division, chromosome rearrangements occur, possibly leading to genetic disorders and diseases.


thanks!,
Komal:)