11. the highest level in the organizational hierarchy of the human body is the
a. atom.
b. organ system.
c. organism.
d. tissue.
12. the brain of the cell is called the
a. endoplasmic reticulum.
b. nucleus.
c. lysosome.
d. cytoplasm.
13. within the cell, the clean-up crew is the
a. endoplasmic reticulum.
b. nucleus.
c. lysosomes.
d. cytoplasm.
14. within the cell, a tubular network that is involved in protein synthesis and transport is the
a. endoplasmic reticulum.
b. nucleus.
c. lysosomes.
d. cytoplasm.

Q11. The answer is C. organism.
Atoms join in molecules, molecules form organelles. Organelles are parts of the cells which combine to form tissues, tissues make organ systems, and finally all of those combine to form organism.

Q12. The answer is B. nucleus.
Inside the cells, genetic information is organised inside the nucleus. It is known as the brain because it is responsible for most of the cell functions. Similarly to the human brain, which sends information to the other parts of an organism, the nucleus sends information and instructions to the other parts of the cell.

Q13. The answer is C. lysosomes.
Lysosomes are cell organelles which contain hydrolytic enzymes. These enzymes are capable of breaking down biomolecules, such as proteins, lipids, carbohydrates, nucleic acid.

Q14. The answer is A. endoplasmic reticulum.
Reticulum is a latin word meaning network. This means that endoplasmatic reticulum is a network (reticulum) inside the cell, in the cytoplasm (endoplasmatic).