Answer:
Radical is an atom or a group of atoms of different elements that act as a single unit during chemical reaction.
Explanation:
For example: Hydrogen, Nitrogen,Nitride,Nitrate,Ammonium, etc.
A. atom
atoms are described to be the basic unit of a chemical element.
Found a similar question with the following choices:
a. living things and flowing water
b. climate and soil properties
c. physical setting and biological community
d. climate and landscape features
In a watershed system, the two main parts are the A. LIVING THINGS AND FLOWING WATER
Answer:
it illustrated natural selection because the most favorable traits live longer than the unfavorable traits.
Explanation:
Answer:
The correct answer is- Immune system
Explanation:
There are physical, chemical and immunological barriers present in our body which helps us to protect from the foreign antigen. They all assist each other and helps in pathogen removal from our body.
The physical barrier includes skin, gastrointestinal tract, respiratory tract, etc which do not allow the microbe to enter the body. Chemical barriers include tear, saliva, acid in the stomach which kills microbes on the body surface.
Immune cells like macrophages, B cells kills microbes when it gets in the body. Lymphatic system also contain immune cells and helps in microbe removal.
So the immune system is assisted by physical barrier, chemical barrier, and lymphatic system.