Unit two: Genes and Heredity Flashcards
Which characteristics are present in chr in metaphase
Aligned at the equator, ds chr and diploid
Which cell cycle stages have ds chr at the end of the stage
G2, S-phase, prophase, prometaphase, metaphase, prophase 1 and 2, metaphase 1 and 2 and anaphase 1
Kangoroos have a haploid # of 8. How many chr are in the end of metaphase 2?
8 chr because haploid
Kangoroos have a haploid # of 8. How many chr are in the end of anaphase 2?
16 chr: sister chromatids separate, cell in mieosis 2 are haploids
Kangoroos have a haploid # of 8. What is the ploidy level at the end of G1?
2n for diploid organisms
The plant extract vincrisne inhibits the formation of spindle fiber. What makes the vincrisne an effective cancer treatment
The role of spindle fibers is to guide the chr to the equator of the cell and separate them by losing subdivisions and shortening. Vincrisne lessens the amount of spindle fibers so they cannot guide them to the center of the cell and separate them and this keeps in check and lessens the uncontrolled cell growth of cancer cells because the daughter cells will not have the same DNA and might not be produced.
Which characteristics are present in chr in anaphase 2 ?
Are separating, diploid for a brief moment, ds chr are separated into ss crh.
How does SPF occur ?
When the G1/S-phase checkpoint is passed, meaning the cell has doubled in mass and contents, growth rate is adequate and presence of human growth factors, SPF is activated
Hows does MPF occur?
When the G2/M checkpoint is passed, meaning the cell has duplicated completely and accurately, the cell has the appropriate mass and contents, growth rate and time elapsed
How does APC occur?
Occurs when the mitotic spindle checkpoint is passed, meaning the chromsomes are attached to kinetochores at the centromere and to two spindle fibers on each sister chromatids from each pole
Why is SPF required?
Required in order to initiates S-phase and DNA replication and so the cell cycle continues
Why is MPF required?
Required in order to initiate breaking down of nuclear membrane, initiate assembly of spindle fibers, stimulate chromatin condensing into chr (Mitosis to start and prophase)
Why is APC required?
Require because it allows the separation of the chr and mitosis to continue, allows chr to decondense, spindle fibers to breakdown and nuclear membrane and inativates MPF
What would happen to the chromosomes if SPF did not activate?
Chromsomes would not replicate, would stay ss 2n
What would happen to the chromosomes if MPF did not activate?
chromsomes would stay ds and 2n and they would stay in the chromatin state, some would get left behind
