B cells mature in the bone marrow, which is at the core of most bones It recognises invaders by the shape of molecules -antigens- on their surfaces. With the help of T cells, B cells make proteins called antibodies. The antibodies will help your body become aware of intruders.
Answer:
cell
tissue
organ
system
human organism
Explanation:
unicellular organisms only have one cell since two or more cells form a tissue their level of organization is restricted to cell
cell
two or more cells form a tissue
two or more tissue forms an organ
two or more organs form a system which must work in coordination for efficiency
two or more systems make up a human organism
Answer:
The correct answer is - Friction occurs irrespective of the state of the matter.
Explanation:
Friction is the force that takes place when there are two different surfaces slide or moves across one another and causes a resistance between surfaces. The friction always takes place opposite direction to the other surface direction of moving.
Pushing a book on a table, pulling a heavy cart on road all are examples of friction. The friction that occurs in liquids and gases is called fluid friction. Thus, the friction takes place irrespective of the state of the matter.
Answer: Viruses, although not living things, do show some characteristics that they are living. Because they can't reproduce by themselves (without a host), viruses are not considered living. They are made of proteins and glycoproteins like cells are. They contain genetic information needed to produce more viruses in the form of DNA or RNA.
They are acellular, that is, they contain no cytoplasm or cellular organelles. They carry out no metabolism on their own and must replicate using the host cell's metabolic machinery.
