BIOM2011 (2021) Exam MCQs

Question 1

What is The major difference between ion channels and ion pumps is

Answer 1

their specificity for moving particular ions

Question 2

How many milliseconds are between the peak of an action
potential and the peak of the cytoplasmic Ca2+ transient during excitation-contraction coupling
in mammalian skeletal muscle (at normal body temperature)?

Answer 2

20 ms

Question 3

What can A potential five-fold increase in cardiac output in a person going from a resting state to one of
intense exercise suggests that

Answer 3

both the stroke volume and pacing rate of the heart must have increased

Question 4

At high heart rates (e.g. 150 bpm), why do the ventricles still fill with blood

Answer 4

because filling is accomplished in early diastole

Question 5

What is the major difference between skeletal and cardiac type excitation-contraction coupling?

Answer 5

a physical coupling of the voltage sensor and Ca2+ release channel in skeletal muscle, and a chemical coupling in cardiac muscle

Question 6

What occurs During tetani in skeletal muscle

Answer 6

there is a fusion of the cytoplasmic Ca2+ transient and force responses that may be complete or incomplete

Question 7

Does the hypothalamus receive both neural and humoral inputs

Answer 7

yes

Question 8

What is the correct pairing of a hypothalamic neurohormone and the
anterior pituitary hormone it regulates

Answer 8

gonadotrophin releasing hormone and luteinising hormone

Question 9

What stimulates Growth hormone release

Answer 9

Starvation, deep sleep, exercise and high plasma amino acid

Question 10

What activates Janus Kinase 2

Answer 10

activated by phosphorylation

Question 11

Compare oxytocin and prolactin

Answer 11

Prolactin acts on alveolar epithelial cells via a G protein-coupled receptor and cyclic AMP

Question 12

What positively regulates vasopressin

Answer 12

solute concentration of extracellular fluid

Question 13

What negatively regulates vasopressin

Answer 13

blood volume

Question 14

What does vasopressin do in the kidneys

Answer 14

decreases water excretion in the kidneys

Question 15

What lateral intercellular junction complexes are calcium dependent?

Answer 15

tight junctions and gap junctions

Question 16

Where would you find ciliated epithelial cells in large quantities?

Answer 16

ventricles of the brain and the lining of the trachea

Question 17

What cell type in the epidermis is responsible for pigmentation of the skin?

Answer 17

melanocyte

Question 18

Both the Na+/K+ pump and the SGLT require energy to function, but they get this energy from different sources. Specifically, where does the Na+/K+ pump get the energy from, and what kind transport is this considered to be

Answer 18

ATP hydrolysis; primary active transport

Question 19

What kind of cells in the intestine produce defensins and what is the function of these proteins?

Answer 19

Paneth cells; defensins are antimicrobial peptides

Question 20

What chemical modification of claudins induces conformational changes in tight junctions to increase paracellular permeability?

Answer 20

phosphorylation

Question 21

Solutes are transported across the membranes of the collecting ducts in the kidney via two distinct cell types, principal cells and intercalated cells. What solutes do these cells transport

Answer 21

Principal cells transport sodium and potassium ions, while intercalated cells secrete and absorb acid or bicarbonate

Question 22

Which has a slower conduction velocity, unmyelinated or myelinated axons

Answer 22

Unmyelinated axons have slower conduction velocity than myelinated axons

Question 23

What are 2 amine neurotransmitters

Answer 23

Noradrenaline and Serotonin (5-HT)

Question 24

What are the characteristics of the dendrites of neurones

Answer 24

They’re variable in length, branched and unmyelinated

Question 25

You measure a current of 100 picoamperes (100 x 10-12 A) moving across a neuron’s membrane when you change the neuron’s membrane potential by 10 millivolts (10 x 10-3 V). Which of the following answers gives the resistance of the neuron’s membrane to current movement?

Answer 25

10 megaohms (1 x 10^7 ohms)

Question 26

What happens in long-term potentiation (LTP) of synaptic transmission

Answer 26

LTP causes changes in postsynaptic NMDA receptor number and phosphorylation

Question 27

What mechanism is involved in clearance of released neurotransmitters from the synaptic cleft?

Answer 27

re-uptake into surrounding glial cells by specific transporters

Question 28

Where are Neuropeptide neurotransmitters and Amine neurotransmitters made

Answer 28

cytoplasm of the synaptic terminal

Question 29

Where are Neuropeptide neurotransmitters made

Answer 29

cell body Golgi apparatus

Question 30

How are Neuropeptides are transported

Answer 30

along the axon to the synaptic terminal in vesicles

Question 31

What are Primary sensory neurons

Answer 31

afferent neurons which can detect sensory stimuli and relay the information to the brain

Question 32

What does lateral inhibition do

Answer 32

limits the interference of overlapping receptive fields

Question 33

Hair Cells characteristics

Answer 33

Hair cells are polarised and respond to one direction of movement, Hair cells transduce mechanical energy to electrical signal and Hair cells are tuned to a specific frequency of stimulation

Question 34

Can muscles in the eye flatten the lens and why

Answer 34

Yes, to change its focal length

Question 35

Which is more sensitive to light, cones or rods

Answer 35

Rods are more sensitive to light, however, cones are most sensitive to one of three different colours (green, red or blue).

Question 36

How is colour perceived

Answer 36

The ratio of responses between cones of different types

Question 37

How is Sound transduction is achieved

Answer 37

via mechanically-gated cation channels, which open and close depending on the direction of bending

Question 38

When a physician tests the knee-jerk, which types of neurons and pathways are involved?

Answer 38

mechanoreceptor neurons, interneurons, and efferent neurons in a reflex arc

Question 39

During an immune response to viral infection in the lung, where would naive T cells would most likely be activated

Answer 39

The lymph node

Question 40

On repeat exposure to a pathogen, a patient is identified with high circulating levels of IgM antibody specific for the pathogen. What is most likely to cause this

Answer 40

IgM being the most appropriate response

Question 41

Within inflamed tissues, what molecule directly results in chemotaxis of immune cells?

Answer 41

complement

Question 42

Many years ago, William Coley found that injection of bacterial extracts would often clear
many types of tumour. This technique was most likely successful because

Answer 42

the activation of dendritic cells was enhanced by the bacterial extracts

Question 43

What immune component is primarily involved in the development of serum sickness

Answer 43

IgG