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WorksheetsBiology HL (Part 6)
Total questions: 20
Worksheet time: 10mins
What structures cardiac muscles have?
Intercalated disc
Y-shaped (branched)
Long and fused together
No difference to skeletal muscle
What is the function of desmosomes?
Form channels between cardiac muscles
Allow rapid movement of ions
Anchor and hold adjacent cells together
Fuse two cardiac muscles together
What structure separates the atria and ventricles?
Thick muscle layer
Fibrous cardiac skeleton
Fibrous cardiac muscle
Thin bones
What are the causes of delay in arrival and passing of impulse at the AV node?
More resistance in AV node
More non-conductive fibre tissues
More Na+ channels at AV node
A lot of gap junction
Which one of these is the normal ECG trace of cardiac cycle?
How does defibrillator help to treat fibrillation?
Stops the heart for a second
Cause depolarisation of the heart
Hyperpolarize the heart
Makes the heart beat faster
What are the actions of steroid hormones toward target cells?
Bind to receptor at the plasma membrane
Promotes transcription of specific genes
Activates a cascade reaction by second messenger
Bind to receptor in cytoplasm
Why peptide hormones only bind to receptor at the membrane?
They are lipophilic
They are hydrophobic
They are lipophobic
Not discussed in the syllabus
What are the differences between anterior and posterior lobe of pituitary gland?
Posterior lobe has portal vessels
Anterior lobe release hormone through endocrine cells
Posterior lobe release hormone produced by hypothalamus
Anterior lobe only have neurosecretory cells connected to hypothalamus
Which of these are correct?
Oxytocin is released by posterior lobe of pituitary gland
Prolactin is responsible for milk ejection reflex
Oxytocin creates negative feedback when infant feed
Prolactin is responsible for production of milk
What is the shape of adult oxygen dissociation curve?
Logarithmic
Exponential
Sigmoidal
Linear
What does cooperative binding of haemoglobin means?
As more oxygen binds to haemoglobin, haemoglobin has lower affinity to oxygen
As less oxygen binds to haemoglobin, haemoglobin has higher affinity to oxygen
As more oxygen binds to haemoglobin, haemoglobin has higher affinity to oxygen
Fetal haemoglobin has lower affinity towards oxygen compared to adult haemoglobin.
True
False
CO2 combines with water to form carbonic acid. The reaction is catalysed by what?
Zinc
Carbonic anhydrase
Iron
No catalyst
To ensure erythrocytes remain uncharged, what happened?
H+ ions are pumped out
HCO3- ions are pumped out
H+ ion are pumped in
React with zwitterions
When the pH is high, haemoglobin has ... affinity for oxygen.
higher
lower
no changes
How does amino acids can act as zwitterions to regulates blood pH?
The R group of amino acid can react to both acids and bases
The carboxyl group can release H+ in alkaline condition
The amine group can absorb H+ in acidic condition
The H group in amino acid can be released in alkaline condition
Where is the respiratory control centre located?
Pituitary gland
Cerebrum
Medulla oblongata
Aortic bodies
What will happen when you live in high altitude after a while?
More red blood cells
Vital capacity will increase
More white blood cells
Muscle will produce more myoglobin
What caused emphysema?
Enzyme elastase breakdown elastic fibres in lung
Macrophages starts eating lung cells
Eating disorder that caused lung breakdown
Chemicals in the air that breakdown lung tissue
