Admin Table of Contents
- 1 Which protein gives the go-ahead signal at the G1 and G2 checkpoint?
- 2 Which checkpoint is considered the most important go-ahead signal to proceed cell cycle?
- 3 What does MPF trigger?
- 4 What is the result of a cell not meeting the criteria to pass the G1 checkpoint?
- 5 Where are chromosomes located in a somatic cell?
Which protein gives the go-ahead signal at the G1 and G2 checkpoint?
These regulatory molecules are mainly proteins of two types: protein kinases and cyclins. Protein kinases are enzymes that activate or inactivate other proteins by phosphorylating them. Particular protein kinases give the go-ahead signals at the G1 and G2 checkpoints.
Which checkpoint is considered the most important go-ahead signal to proceed cell cycle?
The G1/S Checkpoint is the primary point of the cell cycle that is influenced by external signals. The spindle checkpoint ensures that all of the chromosomes are attached to microtubules.
What is the purpose of G2 checkpoint?
The G2 checkpoint prevents cells from entering mitosis when DNA is damaged, providing an opportunity for repair and stopping the proliferation of damaged cells. Because the G2 checkpoint helps to maintain genomic stability, it is an important focus in understanding the molecular causes of cancer.
What event triggers a go ahead signal for the M phase checkpoint?
What event triggers a go-ahead signal for the M phase checkpoint? Chromosomal replication is successfully completed. Kinetochores of all chromosomes are attached to the spindle.
What does MPF trigger?
It stimulates the mitotic and meiotic phases of the cell cycle. MPF promotes the entrance into mitosis (the M phase) from the G2 phase by phosphorylating multiple proteins needed during mitosis. MPF is activated at the end of G2 by a phosphatase, which removes an inhibitory phosphate group added earlier.
What is the result of a cell not meeting the criteria to pass the G1 checkpoint?
What is the result of a cell not meeting the criteria to pass the G1 checkpoint? A. The cell cycle halts. The cell may enter the G0 stage.
What happens if a cell does not enter anaphase?
A) The cell would prematurely enter anaphase. B) The cell would never leave metaphase. C) The cell would never enter metaphase. D) The cell would never enter prophase. E) The cell would undergo normal mitosis, but fail to enter the next G1 phase.
When do chromosomes become aligned at the metaphase plate?
B) metaphase chromosomes become aligned at the metaphase plate. C) chromosomes are grouped during telophase. D) the nucleus is located prior to mitosis.
Where are chromosomes located in a somatic cell?
The somatic cells derived from a single-celled zygote divide by which process? Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell.