Answer:
a. antigen
Explanation:
The Immune system is composed of immune cells that defend the body against foreign substances such as bacteria or virus. Lymphocytes (B and T cells) are one of the main immune cells
Lymphocytes have the ability to recognize and bind to antigens, wich are substances foreign to the body ( i.e bacterial or virus elements) that evokes an immune response.
The planets closest to the star are rocky planets formed by elements with high melting points. Moreover, planets far away are gaseous planets and they are composed of elements with lower melting points.
<h3>Rocky planets and gaseous planets</h3>
The rocky planets consist of silicate rocks and/or metals, whereas gaseous planets are mainly composed of hydrogen and helium.
The rocky planets of the solar system include planets closest to the sun, i.e., Mercury, Venus, the Earth, and Mars.
The gaseous planets of the solar system include faraway planets, i.e., Jupiter, Saturn, Uranus, and Neptune.
Learn more about rocky planets here:
brainly.com/question/17428928
Answer:melanism
Explanation:albino is when an animal has no melanin, which is the chemical that causes pigment (color). Melanism is when an animal has too much melanin and is completely black. That animal is melanistic.
There are 4 significant figures
Answer:
The nitrogen cycle is a repeating cycle of processes during which nitrogen moves through both living and non-living things: the atmosphere, soil, water, plants, animals and bacteria. In order to move through the different parts of the cycle, nitrogen must change forms.
