G12 BIOLOGY HOMEOSTASIS

Which of the following statements correctly describes negative feedback?

• a response to the information by effectors to bring the changed feature back to set-point

• the passing of information about changes to a central control area

• Controls the speed at which impulses travel across neurones

• the change is two-directional

Reorder the following stages of a negative feedback mechanism.

• change detected

• conditions returned to set-point

• conditions in the body change from set-point

• corrective mechanisms switched-off

• corrective mechanisms activated

Match the following

• chemicals that coordinate different body functions

• excretion

• removal of waste products generated by metabolic reaction

• hormones

• removal of an amino group and hydrogen from amino scids

• deamination

• maintenance of a relatively constant environment for cells

• homeostasis

Which substances form the filtrate?

• WBC

• glucose

• inorganic ions

• water

• amino acids

Which of the following statements correctly describes how the walls of PCT are adapted for selective reabsorption?

• the walls of the PCT are lined with receptors for ADH to bind to

• they have many mitochondria to provide ATP for active transport

• their surfaces facing the lumen of the tubule are lines with microvilli

• the walls of the PCT are lined with ciliated and goblet cells