1.1 Various options are provided as possible answers to the following questions - NSC Life Sciences - Question 1 - 2023 - Paper 1
Question 1
1.1 Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A, B, C or D) next to the question numb... show full transcript
Worked Solution & Example Answer:1.1 Various options are provided as possible answers to the following questions - NSC Life Sciences - Question 1 - 2023 - Paper 1
Step 1
1.1.1 Diabetes mellitus is caused by an ...
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Answer
Diabetes mellitus is caused by an undersecretion of insulin (Option B). Insulin is a hormone that regulates blood glucose levels; a deficiency leads to diabetes.
Step 2
1.1.2 Receptors that are sensitive to the low water levels in the blood respond to the ...
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Receptors sensitive to low water levels in the blood are found in the hypothalamus (Option B). These receptors trigger thirst and water conservation mechanisms.
Step 3
1.1.3 The myelin sheath on a nerve cell ...
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The myelin sheath provides electrical insulation (Option A). This insulation increases the speed of nerve impulse transmission along the axon.
Step 4
1.1.4 The structure where sperm are temporarily stored is the ...
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Sperm are temporarily stored in the epididymis (Option A). This structure also matures and stores sperm until ejaculation.
Step 5
1.1.5 Which ONE of the following is a function of the amniotic fluid?
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Amniotic fluid protects the fetus from mechanical injury (Option A). It also provides a cushioning effect and helps maintain a stable temperature.
Step 6
1.1.6 Which ONE of the following represents the corpus callosum?
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The corpus callosum is represented by 2 (Option B). It connects the left and right hemispheres of the brain.
Step 7
1.1.7 Which ONE of the following is the function of part 3?
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Part 3 controls voluntary movements (Option A). It is crucial for executing purposeful actions.
Step 8
1.1.8 The placenta is formed by the ...
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The placenta is formed by the chorion and villi (Option C). These structures facilitate nutrient and gas exchange between mother and fetus.
Step 9
1.1.9 An over secretion of the hormone produced by the thyroid gland may result in ...
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An over secretion of the thyroid hormone may cause losing weight, because of an increased metabolic rate (Option C). The excess hormone accelerates metabolism.
Step 10
1.1.10 Which ONE of the following is an explanation for the difference in testosterone levels between the age groups?
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Answer
The explanation for higher testosterone levels is Group II is higher than Group I because it is needed to inhibit the frequency of sperm in developing males (Option B).
Step 11
1.2.1 The process maintaining a constant internal environment in the human body.
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Homeostasis
Step 12
1.2.2 The organelles responsible for energy production in the cell.
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Mitochondria
Step 13
1.2.3 The disease characterised by the degeneration of brain tissue, leading to memory loss.
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Alzheimer's disease / dementia
Step 14
1.2.4 The layer in the eye that is richly supplied with blood vessels.
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Choroid
Step 15
1.2.5 The type of development in birds in which the young is fully developed and able to move and feed itself.
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Precocial development
Step 16
1.2.6 Groups of cells in the pancreas that secrete insulin and glucagon.
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Islets of Langerhans
Step 17
1.2.7 The structure in the sperm that contains enzymes to dissolve the outer layer of the ovum.
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Acrosome
Step 18
1.2.8 A blood vessel that transports carbon dioxide from the fetus to the placenta.
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