Chapter 11 Cell Cycle, Mitosis Flashcards
In cell division, what does a single cell become?
Two daughter.
What are the two requirements in cell division?
- Two daughter cells must receieve the complete genome present in the single parent cell.
- The parent cell must be large enough to divide in two and still contribute sufficient cytoplasmic components to each daughter cell.
What are the 2 major types of chromosomes?
Autosomes and sex chromosomes. Humans have 22 pairs of autosomes, and the X and Y determine whether we are male or female.
What does chromatin consist of?
DNA and protein.
What is each DNA packaged with histone proteins into forming chromatins?
Nucleosomes.
What are homologous chromosomes?
A pair of the same kind of chromosomes. Homologous chromosomes are similar in length, centromere positions and have the same gene.
What is an allele?
Alleles are different version of a gene. Each allele resides on same location of one of the pairs of homologous chomosomes.
What are the types of homozygous?
Homozygous for dominant allele (AA); homozygous for recessive (aa).
What is heterozygous?
Aa; one dominant and one recessive alleles.
What is a haploid cell?
A cell with 1 complete set of chromosomes.
What is a diploid cell?
A cell with 2 complete sets of chromosomes.
When do chromosomes replicate?
S phase.
What is a sister chromatid and how do they form?
Sister chromatids are genetically identical and they are produced when the chromosomes are replicated during the S phase of the cell cycle.
What is kinetochore? What are they attached by?
They are proteins and each kinetochore is associated with one of the two sister chromatids and forms the site of attachment for a single microtuble.
What are the 2 phases of a cell cycle?
M phase and interphase.
What does M phase consist of?
Mitosis and cytokinesis.
What are the phases in mitosis?
Prophase, prometaphase, metaphase, anaphase, telephase.
What happens in prophase?
Nucleoli disappears; mitosis spindle emerges centrosomes move to opposite pole; chromosomes are condensed with sister chromatids.
What many chromosomes do humans have in a cell at prophase of mitosis?
46.
How many chromatids do humans have in a cell at prophase of mitosis?
92 chromatids.
What happens in prometaphase lf mitosis?
Nuclear envelope breaks down; miotoc spindles attach to chromosomes via kinetochore.
What happens in metaphase of mitosis?
Chromosomes are moved to the mataohase plate; kinetochore of sister chromatids face opposite poles.
What happens in anaphase of mitosis?
Sister chromatids separate (become chromosomes) and moced to the opposite poles by microtubules; elongate the cell; result: two ends of the cell have equal and complete sets of chromosomes.
How many chromosomes do we have in a cell at anaphase of mitosis?
92 chromosomes.
