B-cells fight bacteria and viruses by making Y-shaped proteins called antibodies, which are specific to each pathogen and are able to lock onto the surface of an invading cell and mark it for destruction by other immune cells
Answer:
it is a part of an atom with a positive charge located in the nucleus
Explanation:
The right answer is 4).
The cytoskeleton is made up of biological polymers of proteins, sometimes called fibers because of their large size at the cellular level. They are classified into three categories:
Microfilaments: involves in cytoplasmic phenomena (division, endocytosis, migration).
Intermediate filaments: Maintenance of the nucleus structure.
Microtubules: Involved in the separation of chromosomes during mitosis.
