Human chorionic gonadotropin (hCG) is secrete by the embryo early in pregnancy to keep the corpus luteum for dying. This positive feedback will maintain the corpus luteum, which secretes Progesterone and Estrogens throughout pregnancy, in order to keep the endometrium well to nourish the embryo/fetus.
Answer:
exponential growth
Explanation:
The organisms that are not native of a particular environment but are exposed to live in that particular environment are invasive species. Usually invasive species do not prove useful to the new area and prove harmful to the environment as well. There are some species of organisms that have been accidently introduced to new environment and have been accidently proven to be beneficial. Zebra mussels, being the native to Black Sea when arrived to North America flourished there.
Respiratory system is refers to as the organs which are involved in breathing such as nose, throat, larynx, trachea, bronchi, and lungs. It is also known as respiratory tract.
The circulatory system is refer to as which contains the heart and the blood vessels and blood moves throughout the body in vessels. This circulatory system helps tissues to get enough oxygen and nutrients, and it helps them get rid of waste products.
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What is breathing?</h3>
When person inhale (breathe in), air enters in the lungs, and oxygen from atmosphere moves to body blood. At the same time, carbon dioxide, a waste gas, moves from blood to the lungs and is exhaled (breathed out).
Breathing process is known as gas exchange which is is essential to life.
For more information regarding breathing, visit:
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