Recent questions tagged cell-cycle

Description : List two specific cancer treatments, and tell how each treatment works.

Last Answer : Chemotherapy: Medication usually formulated chemically, and radiation where radiation is directed in certain doses via electromagnetic waves

Description : What are growth factors?

Last Answer : •Some external signals are growth factors, proteins released by certain cells that stimulate other cells to divide

Description : What happens if all the chromosome kinetochores are not attached to spindle fibers? When this occurs, which checkpoint is not passed?

Last Answer : •If the cell does not receive the go-ahead signal, it will exit the cycle, not proceeding onto the S phase

Description : What does MPF trigger? What are some specific activities that it triggers?

Last Answer : •MPF (maturation-promoting factor) is a cyclin-Cdk complex that triggers a cell’s passage past the G2 checkpoint into the M phase

Description : The activity of cyclin-dependent kinases (CDks) rises and falls. Why?

Last Answer : •The activity of cyclins and Cdks fluctuates during the cell cycle, molecularly, it either receives a message to go ahead or not to go ahead.

Description : What is a protein kinase?

Last Answer : The Cell Cycle Clock: Cyclins and Cyclin-Dependent Kinases •Two types of regulatory proteins are involved in cell cycle control: cyclins and cyclin-dependent kinases (Cdks)

Description : What is the Go phase? Describe this phase.

Last Answer : •If the cell does not receive the go-ahead signal, it will exit the cycle, switching into a nondividing state called the G0 phase

Description : What is a cell cycle checkpoint?

Last Answer : The sequential events of the cell cycle are directed by a distinct cell cycle control system, which is similar to a clock The cell cycle control system is regulated by both internal and ... The clock has specific checkpoints where the cell cycle stops until a go-ahead signal is received

Description : What are the components of the mitotic spindle?

Last Answer : •The mitotic spindle is an apparatus of microtubules that controls chromosome movement during mitosis •During prophase, assembly of spindle microtubules begins in the centrosome, the microtubule organizing center

Description : What is a kinetochore?

Last Answer : •During prometaphase spindle microtubules appear and are kinetochores (somewhat track like) where sister chromatids travel along them to the centriole (astor, opposite pole) region. .

Description : In animal cells, the assembly of spindle microtubules starts at the centrosome. What is another name for the centrosome?

Last Answer : •During prophase, assembly of spindle microtubules begins in the centrosome, the microtubule organizing center

Description : What are the components of the mitotic spindle? What is the source of these components?

Last Answer : •The mitotic spindle is an apparatus of microtubules that controls chromosome movement during mitosis

Description : What occurs in meiosis? How is the chromosome number of daughter cells different?

Last Answer : •Gametes are produced by a variation of cell division called meiosis •Meiosis yields nonidentical daughter cells that have only one set of chromosomes, half as many as the parent cell

Description : What is mitosis?

Last Answer : •Eukaryotic cell division consists of Mitosis, the division of the nucleus.

Description : Think carefully, now. How many DNA molecules are in each of your somatic cells?

Last Answer : •In preparation for cell division, DNA is replicated and the chromosomes condense •Each duplicated chromosome has two sister chromatids, which separate during cell division, but a single DNA MOLECULE

Description : Define chromatin.

Last Answer : •Eukaryotic chromosomes consist of chromatin, a complex of DNA and protein that condenses during cell division

Description : How many chromosomes in a human gamete?

Last Answer : 23

Description : Name the two types of gametes.

Last Answer : •Sperm and eggs

Description : What is a gamete?

Last Answer : •Gametes (reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells

Description : Name two types of somatic cells in your body.

Last Answer : Brain and liver

Description : How many chromosomes are in a human somatic cell?

Last Answer : •Somatic cells (nonreproductive cells) have two sets of chromosomes

Description : What is the meaning of genome?

Last Answer : •All the DNA in a cell constitutes the cell’s genome Compare your genome to that of a prokaryotic cell. •A genome can consist of a single DNA molecule (common in prokaryotic cells) or a number of DNA molecules (common in eukaryotic cells)

Description : What is meant by the cell cycle?

Last Answer : •The continuity of life is based on the reproduction of cells, or cell division