The structure of the mature sperm contains a tail, middle section having mitochondria and a head part. The tip of the head part contains <u>acrosome </u>and nucleus. The sperm at maturity, contains a cap like structure at the anterior end. It is termed as acrosome. In this structure, enzymes are present which help the sperm to penetrate into the egg for fertilization. The acrosome allows the plasma membranes of both the cells to fuse and fertilization takes place.
Answer:
the area where a glacier finishes melting.
Explanation:
I got it correct on a quiz.
Answer:
C. Somewhere in an expanding Universe, but not in any special part of it.
Explanation:
The Universe is constantly expanding so their is no exact location or pinpoint where you could call our current location or any location for that manner. You may be able to calculate how far we are from other galaxies and constallations but you cannot calculate how big the universe is.
She would die of suffocation
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.
