BIOM2011 (2022) Exam MCQs

Question 1

The human eye can focus on an object through a part of the eye or the whole eye

Answer 1

The whole eye can change shape on demand to accommodate the focus needs

Question 2

How is the frequency of sound encoded in the cochlea

Answer 2

place coding, the position of the responding hair cells depends on the frequency

Question 3

An efference copy is the copy of what

Answer 3

motor commands sent to predict sensory feedback

Question 4

Why is colour vision lacking in the dark

Answer 4

Due to reduced visual pigments being more sensitive to colour

Question 5

What is happening in hair cells’ signal transduction

Answer 5

Mechanosensitive K+ channels are opening or closing

Question 6

How do sensory receptors inhibit neighbouring receptors

Answer 6

By improving the signal to noise ratio

Question 7

What are Primary sensory neurons

Answer 7

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

Question 8

What’s The major difference between ion channels and ion pumps

Answer 8

their specificity for moving particular ions

Question 9

If the closure of the K+ channels of the sino-atrial node slowed down, the effect on the baseline phase of the cell’s action potential would be

Answer 9

The baseline would depolarize more slowly to threshold

Question 10

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

Answer 10

filling is accomplished in early diastole

Question 11

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

Answer 11

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

Question 12

What are some (four) effects of the parasympathetic nervous system on the heart

Answer 12

Slowed closure of K+ channels, decrease inward Ca2+ current, weakened atrial contraction and slowed pacemaker activity

Question 13

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

Answer 13

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

Question 14

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

Answer 14

IgG

Question 15

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

Answer 15

lymph node

Question 16

On repeat exposure to a pathogen, a patient is identified with high circulating levels of IgM antibody specific for the pathogen. This is most likely caused by

Answer 16

lack of isotype switching

Question 17

Within inflamed tissues, which of the following molecules would directly result in chemotaxis of immune cells?

Answer 17

Complement

Question 18

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 18

the activation of dendritic cells was enhanced by the bacterial extracts

Question 19

What are the mechanisms for clearance of released neurotransmitters from the synaptic cleft?

Answer 19

re-uptake into surrounding glial cells by specific transporters, simple diffusion in extracellular space, rapid breakdown by specific enzymes and endocytosis of unchanged neurotransmitter

Question 20

Can electric and chemical neurotransmitters be modulated in many ways

Answer 20

Electrical neurotransmission can be modulated in many ways, and chemical neurotransmission has limited mechanisms for modulation

Question 21

In neuronal axons where are Voltage-gated sodium channels concentrated at

Answer 21

nodes of Ranvier

Question 22

What are the dendrites of neurons

Answer 22

where most neurotransmitters are received by neurons

Question 23

What is the correct relationship between current (I), voltage (V), and resistance (R)

Answer 23

V = I x R; Ohm’s Law.

Question 24

What does Long-term potentiation of synaptic transmission require

Answer 24

NMDA receptor activation, calcium ion influx, and protein kinase activation

Question 25

Where are growth hormone receptors found in the body

Answer 25

They’re found in most tissues in the body

Question 26

How is growth hormone regulated

Answer 26

By GH releasing hormone and somatostatin via G-protein coupled receptor signalling

Question 27

What mechanism is involved in mediating the increased prolactin secretion during lactation

Answer 27

Increased tyrosine hydroxylase activity and expression

Question 28

What is the pairing of hypothalamic releasing factor and anterior pituitary gland hormone

Answer 28

thyrotrophin-releasing hormone and thyroid-stimulating hormone.

Question 29

Why do oxytocin levels increase during birth

Answer 29

due to a positive feedback loop between the uterus and hypothalamus

Question 30

What is oxytocin

Answer 30

is a small peptide hormone

Question 31

What does oxytocin promote in lactation

Answer 31

promotes breast milk ejection for the suckling infant

Question 32

What can stimulate the release of growth hormone

Answer 32

Exercise, low blood fatty acid concentrations, low circulating insulin like growth factor 1 concentrations and high plasma amino acid levels

Question 33

What are the precursors that polymerize to form the keratin network on the surface of the epidermis?

Answer 33

keratohyalin and eleidin

Question 34

What motor protein is responsible for the movement of cilia?

Answer 34

dynein

Question 35

What is the cell type in the epidermis responsible for sensing touch and temperature

Answer 35

The Merkel cell

Question 36

Within the intestinal epithelium, regeneration and cellular identity of the different types of epithelial cells is mediated by induction of which signalling pathway

Answer 36

Wnt and Notch signalling pathways

Question 37

What kind of cells produce mucin and what is the function of this substance

Answer 37

goblet cells; to create a layer that traps external particles

Question 38

Which hormone produced in the hypothalamus is responsible for increasing water resorption in the kidney and what is the mechanisms of action for this increased water permeability

Answer 38

vasopressin; it causes aquaporin to recycle to cell surface allowing more water molecules to enter the cells

Question 39

What respiratory epithelia region is lined with simple squamous epithelial cells?

Answer 39

The alveolus