Mucus traps pathogenic bacteria. Mucus also attracts viruses that attack pathogenic bacteria.

What part of the immune system do these viruses resemble in their function?

What is the role of the joint capsule in an elbow joint?

What is a similarity between human and insect muscles?

Describe the role of ADH in human osmoregulation.

The diagram shows the chromosomes derived from a single homologous pair following meiosis in a diploid cell.

Which diagram represents the homologous pair from which these chromosomes were derived?

The table shows the results of blood type tests on samples from four individuals. Which row represents an individual who can accept transfusions from people with blood type AB?

The micrograph shows part of a human sperm cell. Which region of the cell is responsible for the greatest production of ATP?

Hormones maintain the thickness of the endometrium during pregnancy. However, insufficient levels of hormones in early pregnancy may cause the breakdown of the endometrium, which leads to miscarriage. What could be a cause of miscarriage in early pregnancy?

Which processes require calcium?

I. Muscle contraction
II. Movement of an action potential along an axon
III. Production of the skeleton of hard corals