Answer:
The right answer to this question is option D. Convergent evolution.
Explanation:
Convergent evolution is a process defined by when an organism develops the same, or at least near that, characteristics, for a specific reason, but they don't have the same origin. In this case, the cacti in both deserts have pretty much the same characteristics, and this happens because both these plants need water to survive, and in order to save it, they have barrel-shaped stems, short-lived leaves, and spines. All of these things help them in saving the water and capturing it when it's possible.
The convergent evolution is when both these organisms develop equally, but are not originally from the same place, the environment being the one to shape this.
Surface area is an important factor in limiting cell growth because
a. the cell can burst if the membrane becomes too large.
b. materials cannot enter the cell if the surface is too large.
c. the cell may become too large to take in enough food and to remove enough wastes.
d. waste products cannot leave the cell if the cell is too small.
Answer:
c. the cell may become too large to take in enough food and to remove enough wastes.
Explanation:
The exchange of substances with surroundings is done by cells by the process of diffusion. The rate of diffusion of substances requires the presence of a higher surface area than volume. As the cells become larger, their surface area is reduced with respect to the volume. Therefore, larger cells can not support the diffusion of substances in and out as required for its proper functioning. If cells are allowed to grow continuously, they will not be able to intake the requires materials such as food and to release the waste outside.
Steroid hormone
- The cell signaling pathways induced by the steroid hormones regulate specific genes within the cell's DNA. The hormones and receptor complex act as transcription regulators by increasing or decreasing the synthesis of mRNA molecules from specific genes.
- Steroid hormones are not able to target every cell within the body, so the overall response is slower. They bind to receptors on the cell's surface and the receptors aid in helping the steroid hormones enter the cell.
- Hormones work by binding to protein receptors either inside target cells or on their plasma membranes. The binding of a steroid hormone forms a hormone-receptor complex that affects gene expression in the nucleus of the target cell.
- Steroids pass into a cell's nucleus, bind to specific receptors and genes and trigger the cell to make proteins.
Learn more:
brainly.com/question/10083019
Answer:
SARS- CoV- 2 is a virus that infects human by the oral-respiratory way in which the virus enters the body and these viruses have spikes on their surface made of spike proteins that allow these viruses to bind with the infected cell.
The infected cells have ACE2 receptor that is protein present on the surface of the human cells. Binding allows the structural change in the virus to fuse and enter in the cell where viruses reproduce them selves with the cell with cell system.