Answer:
There are four bases in DNA, and they combine in a specific way. Adenine pairs with thymine, and guanine pairs with cytosine.
Explanation:
Ancient organism remains, fossil layers, similarities among organisms alive today, similarities in DNA and similarities of embryos.
Answer: After seven months.
Explanation:
The blood carries various substances that must be transported from one part of the body to another. Red blood cells are an important component of the blood because their function is to carry oxygen to the body tissues and exchange it for carbon dioxide, which is carried and removed by the lungs.
Erythropoiesis is the process of red blood cell (erythrocyte) production. It is stimulated by a decrease in O2 in the circulation, detected by the kidneys, which then secretes the hormone erythropoietin. This hormone stimulates the proliferation and differentiation of red blood cell precursors, which triggers an increase in erythropoiesis in hematopoietic tissues and ultimately in the production of red blood cells. <u>In adults, red blood cells are formed in the red bone marrow.</u>
In early developing fetuses, erythropoiesis occurs in the mesodermal cells of the yolk sac. In the third or fourth month, erythropoiesis moves to the liver. After seven months, erythropoiesis occurs in the bone marrow.
Answer:
Lysosome - Janitor, cleans up food particles, waste, and dead cell parts.
Nucleus - Principal, contains DNA and is the control center for the cell.
Cell Membrane - Basically the walls of the school building
Ribosomes - Cafeteria Workers, creates "food" by combining amino acids.
Hope this helps!
CENTRAL NERVOUS SYSTEM INCLUDES THE BRAIN AND SPINAL CORD.