BIOL 373 UNIT 1 QUESTIONS AND ANSWERS ALREADY GRADED A+!!

BIOL 373 UNIT 1 QUESTIONS AND
ANSWERS ALREADY GRADED A+!!
A given signal molecule...

a) May elicit different responses in different target cells or after binding with different
receptor types

b) Will elicit the same response regardless of the receptor type

c) Will elicit the same response regardless of the target cell type CORRECT ANSWERS
a) May elicit different responses in different target cells or after binding with different
receptor types

What is a key difference between a local (paracrine) regulator and a hormone?

a) Local regulators often open ligand-gated channels and affect ion concentrations in
cells; hormones bind with intracellular receptors and affect gene expression

b) Local regulators diffuse to neighbouring cells; hormones usually travel throughout the
body to distant target cells

c) The signal transduction pathways of local regulators do not involve second
messengers; pathways triggered by hormones do involve second messengers

d) Local regulators initiate short-term responses; hormones trigger longer-lasting
responses

e) Local regulators are small, hydrophobic molecules; hormones are either large
polypeptides or steroids CORRECT ANSWERS b) Local regulators diffuse to
neighbouring cells; hormones usually travel throughout the body to distant target cells

What event is common to ALL signal transduction pathways?

a) Phosphates are transferred between molecules

b) Proteins change in conformation/activity

c) Cyclic nucleotides are formed

d) Protons are transferred between molecules

e) Calcium ions bind to/activate proteins CORRECT ANSWERS b) Proteins change in
conformation/activity