The right answer is A.carbon, hydrogen, and oxygen.
Carbohydrates are composed of 3 types of atoms: carbon (C), oxygen (O) and hydrogen (H). Their general formula is written: Cn (H2O) n, (hence the name carbohydrate). There are 2 major carbohydrate families: Simple carbohydrates (monosaccharides and polysaccharides) and complex carbohydrates.
Several foods of different origin contain carbohydrates: sugar, fruits, milk, bread, dough, rice, pulses ... Their role is to bring energy to each of our cells.
The answer is D. they both contain a great variety of nucleic bases.
Answer:
B. It is done by humans to select certain traits useful to us.
Explanation:
There are two main types of selection: natural and artificial. Natural selection is all of the other answers, it is seen over generations and allows the fittest to survive. It also occurs with no human intervention. However, artificial selection is done by humans. It occurs when humans breed animals to best fit their needs. This is best seen in dog breeding.
20.4 21.3 are the correct answers
It is either carcinogens or viruses (I think the first) I hope this helps!
