Only 200 out of 2 000, 000 sperm cells reach the ovum. And only one (in exception to very rare cases of two) sperm cells actually participate in the process of fertilization. In comparison, an average female only produces 400 of egg cells during their lifetime, but the eggs cells are significantly larger than sperm cells.
Answer:
b. reducing molecules
Explanation:
Nicotinamide adenine dinucleotide (abbreviated NAD +, and also called diphosphopyridine nucleotide and Coenzyme I), is a coenzyme found in all living cells. The compound is a dinucleotide, as it consists of two nucleotides linked through their phosphate groups with a nucleotide that contains an adenosine ring and the other that contains nicotinamide.
In metabolism, NAD + participates in redox reactions (oxidoreduction), carrying electrons from one reaction to another.
Coenzyme, therefore, is found in two forms in cells: NAD + and NADH. NAD +, which is an oxidizing agent, accepts electrons from other molecules and becomes reduced, forming NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD +. However, it is also used in other cellular processes, especially as a substrate for enzymes that add or remove chemical groups of proteins, in post-translational modifications. Due to the importance of these functions, the enzymes involved in the metabolism of NAD + are targets for drug discovery.
This represents the example of founder effect.
The founder effect is a term in genetics that describes the loss of genetic variation as a result of new population formation by a very small number of individuals from a larger population. Small group of migrants (the afrikaner population of south Africa) that is not genetically representative of the larger population (Europe population) forms a new population with lower genetic variation.
Answer:
Xylem
Explanation:
Water moves from the roots to the leaves through tissue called the xylem, in a process called transpiration. As water evaporates out of the leaf, more water is 'pulled upwards' to replace what has been lost.
Answer: Option D
Explanation:
Phosphorus assists in energy metabolism.
It helps in the usage and storage of energy in the body. Also, whenever, phosphorus levels in the blood get too low energy levels tend to drop. This could lead to weakness in the muscles and fatigue
