Chapter 9, How Cells Reproduce
What are the three functions of mitosis?
Increases body size during growth, replacement of dead worn out cells, and repair of damamged tissue.
After mitosis is completed, do the daughter cells contain the same number and type of chromosomes as the parent cell?
They have the same DNA molecule and associated proteins.
What is happening in the cell during interphase?
The cell increases in mass, and it roughly doubles the number of components in the cytoplasm, it also duplicates its DNA.
Is interphase or mitosis the longest portion of the cell cycle?
What happens during G1 or Gap 1?
Interval of cell growth before DNA replication. (Chromosomes unduplicated)
What happens during S or Synthesis?
Interval of cell growth when DNA replicated is completed. (Chromosomes duplicated)
What happens during G2 or Gap 2?
Interval following DNA replication; cell prepares to divide.
What are the phases of interphase?
G1, Synthesis, and G2.
What is occuring during mitosis?
Prophase, metaphase, anaphase, and telophase.
What is the mitotic spindle and what is its function?
A dynamic array of microtubules that moves chromosomes with respect ot its two poles during mitosis or meiosis.
Where does crossing over occur?
Prophase I of meiosis.
Does variation in hereditary material occur in mitosis?
No, it is involved in growth, tissue repair, and asexual reproduction.
What are sister chromatids?
Two members of a duplicated chromosome, each the same DNA molecule and associated proteins. The two stay attached at the centromere until separated from eachother during mitosis/meiosis.
Do bacteria (prokaryotes) reproduce by mitosis?
No, they produce by prokaryotic fission.
What is meant by the term somatic cell?
A body cell that is of multinucleated eukaryotes. I.E: Glial Cell.
What are gametes?
Reproductive cells. I.E: Sperm and Egg.
Are somatic cells diploid or haploid?
Are gametes diploid or haploid?
What is meant by the term diploid 2n?
2 of each type of chromosome.
What is meant by the term haploid 1n?
One set of chromosome number.
What is Prophase?
Chromosomes condense into rodlike forms, and microtubules form a bipolar spindle. Nuclear envelope breaks up, some microtubules harness the chromosomes.
What is Metaphase?
All duplicated chromosomes are aligned midway between the spindle poles at its equator.
What is Anaphase?
Microtubules move the sister chromatids of each chorosome apart, to opposite spindle poles.
What is Telophase?
A new nuclear envelope forms around each of two clusers of decondencing chromosomes.
What is Cytokinesis?
End process of the cell cycle, cytoplasm recreated creating two new cells.
How does cytokinesis occur in plant cells?
They have a cell plate.
How does cytokinesis occur in animal cells?
They have a contractile ring.
What is a chromosome?
In prokaryotes, circular DNA double hexlis with a few proteins attached. In eukaryotes, linear DNA double helix.
What is a germ cell?
Immature reproductive cell.
What is a histone?
Double stranded DNA proteins.
What is a nucleosome?
Beads in DNA, smallest unit of structural organization in eukaryotic chromosomes.
What is Mitosis?
A nuclear division mechanism that occurs in somatic cells (body cells) of multicelled eukaryotes.
What is Meiosis?
A nuclear division mechanism that preceeds the formation of gametes or spores, and it is the basis for sexual reproduction.
What is a centromere?
Constricture region of eukaryotic chromosome, organizes growing microtubules into a array inside cillium or flagellum.
What is the cell cycle?
A series of events from one cell division to the next.
What is the chromosome number?
Sum of all chromosomes in a cell.
What is Kinases?
Class of enzymes that can activate other molecules by transferring a phosphate group to them.
What is Growth Factors?
Checkpoint proteins that promote transcription of genes that have roles in the bodies growth.
What is a Tumor?
An abnormal mass.
What is a Neoplasm?
Abnormal mass of cells that have lost control of how they grow and divide. EX: Moles.
What is Cancer?
Abnormally growing and dividing cells of malignant neoplasms.
What is the most malignant type of cancer?
What is the least malignant type of cancer?
Basal cell carcinoma.
What is the second least malignant type of cancer?
Squamous cell carcinoma.