chromosomes and cell division (mitosis)
Which of the following checkpoints does not occur late in G1? A check that the cell is large enough for division A check that growth factors are present A check that nutrients are sufficient A check that chromosome replication has been successfully completed
A check that chromosome replication has been successfully completed
What is cytokinesis and when does it occur?
Cytokinesis is the division of the cytoplasm. This process begins toward the end of mitosis and does not end until after mitosis has been completed. Begins formation of cleavage furrow.
True or false. Mitosis takes place during M phase of the cell cycle, which is longer than interphase.
F. Mitosis does indeed take place during M phase, but M phase is shorter than interphase; cells spend most of their time in interphase.
Mitosis cycle step by step-
G1 (growth period for cell and chromosomes), Interphase (s) chromosomes replicate and grow, G2 (chromsomes then have 2 chromatids and final preparations are made, mitosis then begins (cell division). Mitosis has 4 steps - prophase metaphase anaphase telophase. Final step is cytokinesis.
Which of the following statements is accurate when referring to a cell about to begin mitosis? Mitotic spindles have reached into the nucleus and have attached to the sister chromatids. Identical sister chromatids have formed and each is a newly replicated DNA double helix. A cleavage furrow forms. The nuclear envelope begins to break down.
Identical sister chromatids have formed and each is a newly replicated DNA double helix.
most of the cells life is spent in ___.
Interphase. Growth occurs here. Cells are about to replicate DNA
The chromosomes line up in the center of the cell during which phase of mitosis?
Metaphase
The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?
Prophase
The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?
Telophase
What must happen before a cell can begin mitosis?
The chromosomes must be duplicated.
the ____ undergoes mitosis. This was made by fertilization from parents.
zygote
anaphase is when-
chromatids separate
At the end of the mitotic (M) phase, the cytoplasm divides in a process called
cytokinesis
in prophase microtubles-
form mitotic spindles and nuclear envelope breaks up
metaphase the mitotic-
fully forms and chromsomes line up at center of cell
DNA is replicated during __________.
interphase
Mitosis step by step
interphase, prophase, metaphase, anaphase, telophase and cytokinesis
in telophase chromosomes become
less condensed and nuclear envelopes form
During which stage of mitosis are chromosomes lined up in the center of the cell?
metaphase
A process that parcels out the duplicated copies of genetic material for cell division in eukaryotes is called ________.
mitosis
The most appropriate form of cell division for repairing an injured tissue is ________.
mitosis
prophase is when __ forms
mitotic spindle
telophase and cytokinesis is when-
nuclear envelopes form
In which phase does the chromatin condense into chromosomes, the nuclear membrane disintegrates, and the centrioles migrate to the poles as spindle fibers are organized?
prophase
prophase, anaphase, metaphase, telophase telophase, anaphase, metaphase, prophase anaphase, prophase, metaphase, telophase prophase, metaphase, anaphase, telophase
prophase, metaphase, anaphase, telophase
In anaphase sister chromatids-
separate and move to opposite poles
metaphase is when-
sister chromatids center
Which stage of mitosis is characterized by the disintegration of mitotic spindles and the formation of two new nuclear membranes?
telophase
cytokinesis is when
the cytoplasm divides
haploid-
1 set of chromosome
diploid
2 set of chromosomes
A certain species of animal has six pairs of chromosomes. How many DNA molecules are present in the nuclei of these animals during G2 phase?
24. DNA replication is completed during S phase, which occurs prior to G2 phase. Since each chromosome (12) is replicated, there are 24 DNA molecules in the nucleus during G2 phase.
If a cell begins mitosis with 36 chromosomes, there will be ________ chromosomes in each cell after mitosis and each daughter cell will be ________ genetically.
36; identical
How many chromosomes arranged in how many pairs would be shown in a normal human karyotype?
46,23
A cell with a diploid number of 24 fails to undergo cytokinesis while performing mitosis so that the daughter cells do not form. How many chromosomes will be in the resulting cell?
48
The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?
Anaphase
During which phase of mitosis do spindle fibers pull the chromosomes to opposite poles of the cell?
anaphase