Practical - questions the cell cycle fill in the blank - PDF

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BIOL190A Midterm2 review

11/2/2014 9:09:00 PM

BIOL190A Review for midterm 2 The cell cycle and sexual life cycles (Ch.12, pp.243-251, 252-253, Ch.13) The continuity of life the continuity of life consists of

Life also has generational continuity in terms of things other than DNA sequences, for example, ‘Blueprint’ is a metaphor to refer genes and DNA. Because blueprint is

and genetic information is .

B. The cell cycle 1. The cell cycle is a controlled sequence of events that comprises cell growth and division. G1 = S =

2. Cells that progress through the cell cycle Growing (Zygote ->

cells in young animals -> Eight-cell stage -> Blastula ->

) cells in mature animals

cells in ( ) of plants cells at the growing points of and cells that divide to repair an injury in

and

3. Cells that do not normally progress through the cell cycle differentiated cells performing specialized functions Specialized = G0 (zero) = outside of the cycle = , (e.g. ) The cell cycle is subject to complex control. Cell growth, division of the cell’s contents, and division of the cell’s genetic information must be coordinated. (= no skipping parts.) = check cell’s problems by genetic. Cancer = cell controlled disease. C. Mitosis Mitosis is a division of the that involves an equational division of the chromosomes. Chromosomes consists of % and % After mitosis is finished, each daughter nucleus will be genetically identical to mother nucleus and each other. (There are some exception. E.g. 46 ch -> 46 & 46) Before mitosis, the chromosomes are duplicated in S phase to give two One chromosomes = chromatids Stages of mitosis 1. Prophase, chromosome starts to condense, spindle gives chromosomes energy to move 2. Prometaphase, spindle microtubules attached to kinetochores (complex of protein) 3. Metaphase, chromosomes become a line on a metaphase plate, spindle are attached 4. Anaphase, chromosomes split, motor protein (ATP) 5. Telophase, nucleus are split into two and new nuclear envelop are developed, chromosomes are decondense

Mitosis is usually followed by two separate cells.

, division of the cell’s contents into

Animal cell – furrow appearing when in muscle, some free space for

, actincells.

interaction

Plant cells – not the same system as animals because of = . A

, vesicles

is a cell in which one or more rounds of mitosis has occurred

without cytokinesis. E.g coconut water, caulerpa taxifolia (marine algae) D. Meiosis 1.

Meiosis is a division of the nucleus that involves a

of

the chromosomes. This is necessary for organisms with sexual life cycle. 2.

Each

daughter

nucleus

will

get

half

the

chromosomes

of

the

nucleus.

Every species has its characteristic chromosome numbers. Chromosome number in a nucleus before meiosis: or Chromosome number after meiosis: or In a diploid cell there are two similar, but not identical, versions of each kind of chromosomes. These two versions are called For each pair of in each of your cells, you received one homologue from your and one from your at fertilization. Before meiosis the chromosomes must be duplicated, as they are before mitosis. E. Chromosome sets 1. one set of chromosomes = for each chromosome in the genome, allele of each gene 2. Haploid nucleus = chromosome set(s), homologue per chromosome, allele per gene 3. Diploid nucleus = chromosome sets, homologues per chromosome, alleles per gene. F. Sexual life cycle Sexually reproducing organisms have both 1n and 2n phases of their life cycle. Life cycles of sexual organisms can be represented in terms of chromosomes

there is no mitosis after meiosis because nuclear envelop can’t be divided anymore, but meiosis can happen after mitosis....