B - Hydrogen Bond
A and D are incorrect as these are bonds either between metals and nonmetals or non metals and non metals. C is incorrect as this term is a joining of sugar molecules.
Hope this helps!
All of these are essential to survive
An animal's physiology can indicate it's diet based on what the animal's body can handle processing. For example, animal's with strong bones and teeth can break down food that is tough to eat, this helps obtain energy alot quicker. For instance, giraffes have long and slender necks that are perfect for reaching up to trees. The giraffe's diet would consist of vegetation located in high levels.
B: Antigens
Explanation: Antigens itself are the invaders that causes an infection or a disease in living organism. They do not protect against invaders in non-specific response as they themselves are the ones who are invading the body.
Digestive enzymes are the enzymes that act on a particular substrate for its action at a particular PH.
Stomach acid is the hydrochloric acid that keeps the PH of the stomach low and prevents the growth of unwanted pathogens.
Lysosomes have digestive enzymes in it. It performs the process of phagocytosis.
The sugar-phosphate backbone is an important structural component of DNA. It consists of 5-carbon deoxyribose sugars<span> and </span>phosphate<span> groups.
Hope this helps
Have a good Day</span>
