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.
Answer:
It provides a defined order to the succession of organisms.
Explanation: Relative dating of rocks involves the relative or comparative determination of age with reference to past events. There are several principles involved in carrying out relative dating. Some of these principles are:1. Principle of inclusion2. Principle of inclusion 3. Principle of fossil and fauna succession The Principle of fossil and fauna succession postulates that fossil and fauna succeeds one another in a definite pattern. It is this defined order that we use to achieve relative dating of rocks. Plant and animal remains constitutes the fauna and fossils used in dating the rocks. When we find a particular fossil in a rock, we can place that rock in its appropriate geological time. We can even go further by correlating rock types using their fossil contents.
I think the answer is A. not entirely sure
D, all of the above. Your body sweats when it gets too hot to cool the body, and shivers when it gets too cold to heat the body. The nervous system is responsible for sensing everything in and around the body.
