Explanation:
In the megasporan- gium of each ovule, the megasporocyte divides by meiosis, producing four megaspores. One survives and forms a female gametophyte. Fertilization: In nucleus of developing endosperm-- Double fertilization occurs. One sperm fertilizes the egg, forming a zygote.
Is this a question or a moment of someone needing advice?
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:
B) how changes in development underpin the evolution of morphology.
Explanation:
Evolutionary developmental biology is the new field of research in biology which studies the combined relationship of the evolution and the developmental processes.
This interdisciplinary study compares the developmental biology in terms of evolution or in a way that how the developmental biology process evolved in the organism on the basis of studying the phenotypic features of the organisms.
Thus, Option-B is the correct answer.
Answer:
B. increase, because the partial pressure of CO2 in the blood will decrease.
Explanation:
The presence of carbon dioxide gas in blood imparts H+ ions due to its reaction with H2O and thereby, lowers down the blood pH.
When more air reaches alveoli, the rate of gaseous exchange is increased. More of the carbon dioxide is removed from the blood and is released out of the body via exhalation.
Removal of carbon dioxide from blood would increase the pH of the blood since the partial pressure of CO2 in the blood would decrease.
