The secretion of human growth hormones (HGH) is regulated at the genome level by genetic and epigenetic factors (environment and diet among others). And the expression of the gene of this hormone differs from one individual to another, so the quantity produced differs between individuals, which explains why we observe individuals of different sizes in a population.
Growth hormone acts by interaction with cellular receptors, it affects carbohydrate, lipid and protein metabolism.
A key component of growth is the growth hormone releasing factor or the growth regulating factor (GH-RF or GRF). This chemical messenger is produced in a part of the brain called the hypothalamus. GH-RF allows the pituitary gland (the "master gland" involved in the growth process) to secrete growth hormone, the main hormone responsible for a person's growth.
GH is not only involved in growth phenomena, it also plays a role in the fine regulation of reproductive phenomena in both male and female mammals.
Limits to variation The most obvious limit to natural selection is that suitable variation may not be available. This may be because certain phenotypes cannot be built, being ruled out either by physical law or by the properties of biological materials.
Answer:
insects
Explanation:
There are variety of insects and is considered a species. A big fish is just a description so is small dog. And cricket is simply just cricket.
Answer:
B) light dependent reaction: electron transport and the splitting of water
Explanation:
The source of ATP and NADPH, which are required to synthesize glucose is a light-dependent reaction.
During the process of photosynthesis, light energy is required to tranport electrons that produces ATP and NADPH and splitting of water, generating O2.
Photosystem I (PSI) absorbs the light energy and electrons supplied from PSII (Photosystem II) are transferred to the protein ferredoxin, which further donates electrons to electron transport chain that produces ATP and to the electron carrier NADP+ to form NADPH.
Hence, the correct option is B.
They are all compounds. This means that several elements make them up. H2O, or water for example, is a mix of two Hydrogen (H) and one Oxygen (O).
