This is because not all genes are expressed at the same time, so not all the proteins are present at a certain moment. The mechanisms that cell uses to control gene expression are called regulation of the gene expression. Thanks to regulation of the genes, cells have the ability to increase or decrease the production of specific gene products such as proteins. This property is important for the adaptability of an organism because it allows the cell to express protein when needed.
The menstrual cycle is practically controlled by a system of hormones that is necessary for reproduction, and when the hormone reaches a heightened level, something called estradiol is made, then the stimulation of the ovaries by a luteinizing hormone.
Once that hormone begins developing, the ovaries make an egg that quickly becomes an ovum. The ovary then releases one egg or two during ovulation. The endometrium (the part that sheds its own cells for the menstruation) peaks after ovulation and changes the lining of the uterus to prepare for the hectic process of pregnancy and child labor.
Hope that was helpful.
Answer: b. fossil fuels are nonrenewable, so humans will run out of them eventually. burning fossil fuels also contributes to global climate change by releasing carbon dioxide into the atmosphere.
Explanation:
Fossil fuels are limited and we will run out of them eventually. They cannot be replenished in a single human's lifespan. Fossil fuels contribute to the destruction of ecosystems, but not only that. They release carbon dioxide into the atmosphere that warms the Earth. Therefore, anything other than B. would be incorrect.
Homologous structures are common structures in different species that perform different functions and may have look similar in structure.
Example- The different animals have bones that appear very similar in form and function and seem to be related.
