Water flows through a selectively permeable membrane in a process called __________, but water molecules cross the membrane more easily through channels of transmembrane proteins called __________.

The plasma membrane of cells lining the small intestine has __________, which are specialized for absorption of nutrients.

What is indicated by the arrow?

Organs are made of tissues.

Which of the following lists levels of human structure from the most complex to the simplest?

Homeostasis and occupying space are both unique characteristics of living things.

__________ is a monosaccharide, whereas __________ is a polysaccharide.

Nucleic acids are __________ of __________.

Microvilli and cilia differ in their function, but have the same internal structure.

This feedback loop is an example of which of the following?