Answer:
This question lacks options, the options are:
a) Negative primary production
b) Net primary production
c) Secondary production
d) Negative secondary production
e) Positive primary production
The correct answer is b.
The total amount of chemical energy produced by autotrophs, such as plants and phytoplankton, is called gross primary production. The energy that remains after plants use some of the gross primary production to fuel their own metabolism is known as <u>net primary production</u>.
Explanation:
Net Primary Production (NPP) is the value that results from the difference between gross production and respiration of the primary producers themselves. It manifests as growth and / or reproduction. It represents the matter and energy available for the next trophic level, that is, the net primary production is what is left after subtracting the energy that plants use for their metabolism or maintenance (such as breathing, tissue construction and reproduction).
Answer: fibrous periosteum
<span>The diaphysis is the main shaft of a long bone which is made up of cortical bone which contains bone marrow and fats. It is covered by a fibrous connective tissue called the fibrous periosteum. The cells in this layer are densely packed and contain blood vessels, nerve endings and lymphatic. </span>
Answer:
D. Transport of oxygen through a placenta to a fetus.
Explanation:
Zygotes are fertilized egg cell, zygotes aren't produced in the ovaries but ovums or egg cells are produced in the ovaries. So option A is false.
Fertilization is internal not external in human. Option B is wrong.
Production of milk happens in the mammary gland (the breast) not in the reproductive system. Option C is false.
Transport of oxygen through a placenta to a fetus. The placenta is a vascular organ which is implanted in the wall of the uterus (a part of the female reproductive system) and links to the foetus through the umbilical cord.
Answer:
Adaptive immune defense system consists of lymphocytes like B-lymphocytes and T- lymphocytes. B-lymphocytes provides humoral immunity while T- lymphocytes provide cell-mediated immunity to the body.
99% of lymphocytes circulate freely in the blood and lymph. B lymphocytes differentiate into plasma B cells and B memory cells when interact with antigen presented by T helper cells.
Then plasma cells secrete antibodies in the circulation which binds to extracellular antigens through antigen-binding site. Then the bounded antigen is recognized by receptors present on phagocytic cells. This receptor binds the Fc region of antigen bounded antibody and destroy the antigen by phagocytosis.
