1. Explain why neither cyclins nor kinases alone can cause a cell to progress through the cell cycle.
As cyclin accumulates, it activates their kinases that turn on the pathway to mitotic spindle formation, and so on.
2. How do controls of the cell cycle protect multi-cellular organisms from accumulating large numbers of damaged or defective cells?
The checkpoint control is responsible for multi-cellular organisms for not accumulating large numbers of damaged or defective cells. Checkpoint controls consist of proteins that detect mistakes and damage and quickly halt the cell cycle until repairs are made. When this occurs, the cell is said to be in cell-cycle <span>arrest.
</span>3. What is the difference between a cancerous tumor and metastasis?
Cancer is cause by mutations in the genes that encode these proteins can lead to uncontrolled growth. Cancer is when there is uncontrolled cell growth and reproduction. Metastasis is caused by tumors when they grow and interfere with the surrounding tissue or cells and break off and spread around the body. Cancerous tumors cause metastasis, and tumors are caused by mutations in genes that lead to uncontrolled growth.
4. What are the functions of tumor-suppressor genes and protoncogenes in noncancerous cells?
The genes that encode the checkpoint proteins are called tumor suppressors because they suppress the development of cells into tumors. If mutations inactivate these genes, the cell-cycle break is removed with or without a signal from the outside. Proto-oncogene’s are involved in promoting cell division, mutations can cause them to become oncogenes, or cancer genes which stimulate cells to leave G0 and divide whether or not it is a signal.
Less people would buy and the economy's health would go down.
They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe.
If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
They are breaking down the toxins, I presume.
Amino acid reactions. Amino acids via their various chemical functionalities can undergo numerous chemical reactions.
