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Hello Mdm Dini, for the 2023 MCQ Q14, why is the semi-lunar valve closed instead of open if the ventricular pressure is higher than aortic pressure?

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Hello Mdm Dini, if we were to answer a question that says “define excretion”, do we have to include examples like “metabolic waste products such as carbon dioxide and excess water”, or can our answer simply be “the removal of metabolic waste products, toxic substances and substances in excess of body requirements”? Thank you!

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Mdm Dini, could I check where we are expected to know about what we learnt in lower secondary for cells? Example mesophyll (upper epidermal cells, guard cells …)

Thank you!

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Mdm Dini, could I just confirm whether vesicles stores substances, or only transports substances?

Thank you!

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Mdm Dini, may I check whether there is physical/mechanical digestion in the small intestine? In our notes it states that physical digestion only takes place in mouth and stomach, but isn’t there also peristalsis that occurs in small intestine?

Thank you!

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Mdm Dini, for movement of substances through osmosis, when describing movement of water molecules from plant/animal cell to a solution of low water potential, do we need to specify that "by osmosis, water moves out from the vacuole and cytoplasm of the cell to the solution through ppm" or can we just say water moves out of the plant/animal cell without specifying the specific parts ("vacuole and cytoplasm") Thank you!

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Mdm Dini, for the area of respiration during exercise, in the notes and textbook, it states that ‘there will be a shortage of oxygen supplied to the muscles and the muscles are said to incur an oxygen debt.’ But isn’t oxygen debt the amount of oxygen required to remove lactic acid and not because there is a shortage of oxygen?

Thank you!

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I think you went through in class already but sorry i forgot :(((

For the assignent qn 12 part (b), why must you write "deposition of fatty substances on inner walls of the artery" and cannot write "inner surface of the arteries." Bcs in the school notes and TB they use inner surface of the arteries.

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on pg 12 of the notes under events in the right atrium "This causes the pressure in the right atrium to be higher than the right ventricle, hence bicuspid valve opens" can i just confirm that its a typo and supposed to be tricuspid?

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Mdm Dini, for the school notes on transport in humans, for the part addressing the LO of "outline the cardiac cycle in terms of what happens during systole and diastole"... for stage 2, during atrial systole and ventricular diastole, it's mentioned that bicuspid and tricuspid valves are pushed open as well as semi-lunar valves are closed (thus producing the 'dub' sound). So may I confirm that at this stage the ventricles are being filled with blood and the aorta is pumping blood to all parts of the body at the same time?

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