What is the immune system?

A. The group of cells and organs that protect the body from disease.

B. A group of cells that undergoes apoptosis to protect the body.

C. A group of organelles that digest particles that invade the cells.

D. The group of cells and organs that turn food into energy for the body.

a .

Explanation:

a group of cells and organs that protect the body from disease

B

Explanation:The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. ... Even simple unicellular organisms such as bacteria possess a rudimentary immune system in the form of enzymes that protect against bacteriophage infections.

the answer to your question is:

c. complementary base-pairing

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle