Answer:White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system.
Explanation:
The statement “One of the first steps in harnessing geothermal energy is to drill a well into a geothermal reservoir.” Is true. The answer is letter A. The energy in the Earth’s crust comes from the formation of the planet and radioactive decay of materials.
Answer:
phytoplankton and bacteria
Explanation:
Homologous structures are organisms which are grouped according to phylogeny, reveal that closely related organisms have more similar structures for example whales were once classified as a fish because they live in the water and they have flippers. Flippers are homologous to human arms and legs and they are therefore closely related to human beings.
Similar embryological development. Embryos of various vertebrates all look similar, including features. For example, tails which are not seen in the maturity suggests that all organisms evolved from a common ancestor, still, we express and share genes that are shared and belie ancestry.
Shared biochemical molecules such as DNA and ATP structure of molecules reflect descent with modification. The evidence of universal common ancestor is being reflected in the universality of DNA as a genetic material.
The genetic code in the machinery of DNA expression and replication. The relatedness within groups of organisms is reflected in the similarity in their DNA sequences. This is the exact pattern to be expected from diversification and descent from a common ancestor.
Answer:
X inactivation
Explanation:
The female mammals have double the number of X-linked genes as compared to their counterpart males. During early embryonic development, either the maternal or paternal X chromosome in all the cells of a female is inactivated by the process of heterochromatinization. The inactivated X chromosome is present in the form of a Barr body. This inactivation of the X chromosome is a random event.
The inactivated X chromosome of a cell remains in the same state in all of its progeny cells. In this way, the process of X inactivation balances the dosages of X-linked genes between males and females.
