Cell Cycle
Before a cell can proceed to mitosis from Gap 2 it must do what?
Pass a critical checkpoint
Loosely coiled DNA in the nucleus during interphase is called
Chromatin
Describe the events that take place in prophase during mitosis
1. Chromatin condense (shorten to form chromosomes)
2. Nuclear envelop disintegrates
3. Centrosomes migrate to opposite sides of cell
Are the cells haploid or diploid at the end of meiosis I?
haploid due to the division of homologous chromosomes
What is an identical form of the same gene?
homozygous allele
During interphase, a cell grows, duplicates organelles, and __________
synthesizes DNA
An exact (identical) copy of a chromosome attached at a centromere
chromatid
What is the main difference between prophase and telophase?
Prophase there is only one nuclei, telophase two nuclei exist in one cell before cytokinesis
What is divided in meiosis II?
sister chromatids
If a plant's alleles for height ate tt, what is true of its parents?
both parents contributed a recessive allele
During which of the following stages of the cell cycle does the cytoplasm divide?
cytokinesis in the M-phase
An organelle that makes microtubules to pull chromosomes apart during mitosis
centrosome
How are the chromosomes different in prophase compared to telophase?
Chromatids are attached at centromere in prophase, in telophase chromosomes are not attached to another chromatid.
What happens at prophase I in meiosis that is different than mitosis?
Tetrads align and crossing over occurs
What is the probability that the offspring of a homozygous dominant individual and a homozygous recessive individual will exhibit the dominant phenotype?
100%
Name two internal factors that control the cell cycle.
Kinases and cyclins
A protein that helps to coil DNA
histone
Describe metaphase.
Chromosomes align at the equator
What happens in metaphase I of meiosis that produces genetic diversity?
Chromosomes line up on the equatorial plate independent of one another so that they assort randomly. Independent assortment.
Imagine a cross of two heterozygous parents. The ratio of offspring that have brown eyes to the offspring that have blue eyes is?
3:1
What are proteins from outside a cell called that stimulate the cell to divide?
Growth factor
Two similar chromosomes that you inherit from your parents are called
homologous chromosomes
Describe anaphase.
Spindle fibers pull chromatids apart to create new chromosomes for each cell
What is the law of Segregation (Mendel's 1st Law)
Alleles separate randomly during anaphawe 1 so that each gamete has only 1 copy of each allele but with different combinations
If a person is born with a recessive phenotype, what are the following genotypes could her parents have?
Rr or rr