Study the graphical representation of a normal menstrual cycle and answer the questions - NSC Life Sciences - Question 3 - 2016 - Paper 1
Question 3
Study the graphical representation of a normal menstrual cycle and answer the questions.
**3.1.1** Name the source of the hormones below:
(a) Oestrogen and
(b) Pr... show full transcript
Worked Solution & Example Answer:Study the graphical representation of a normal menstrual cycle and answer the questions - NSC Life Sciences - Question 3 - 2016 - Paper 1
Step 1
Identify the source of the hormones below:
(a) Oestrogen
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Answer
The source of oestrogen is the Graafian follicle.
Step 2
(b) Progesterone
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The source of progesterone is the Corpus luteum.
Step 3
Describe the effect on the uterine wall when there is …
(a) an increase in the level of oestrogen between day 4 and 14.
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As the level of oestrogen rises, the endometrium of the uterus becomes more vascular and thicker, preparing for possible implantation of a fertilized egg.
Step 4
(b) a drop in the level of progesterone.
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A drop in the level of progesterone leads to degeneration of the endometrium, which eventually causes menstruation.
Step 5
What possible conclusion can be drawn if the progesterone level remains high after the 28th day of the cycle?
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If progesterone levels remain high after the 28th day, this indicates potential confirmation of pregnancy or conception, as the hormone is necessary to maintain the endometrium.
Step 6
Explain why the insertion of IUD (Intra Uterine Device) into the uterus does not prevent the menstrual cycle but prevents pregnancy.
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The IUD works as a contraceptive device by preventing implantation of a fertilized egg, however, it does not interfere with the hormonal processes that regulate the menstrual cycle.
Step 7
Identify parts:
(a) A
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Part A is the Placenta.
Step 8
(b) B
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Part B is the Umbilical cord.
Step 9
(c) D
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Part D is the Amniotic fluid.
Step 10
Explain why the premature breaking of the part labelled C is regarded as fatal or life threatening to the survival of the foetus.
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Premature breaking of the amniotic sac can lead to quicker dehydration of the fetus, increased risk of infections, and lack of protection from mechanical shock.
Step 11
Which one of the labelled part is responsible for the production of progesterone?
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Part A, the Placenta, is responsible for the production of progesterone during pregnancy.
Step 12
Describe how exchange of nutrients, waste products and gases takes place between the mother and the fetus even though the mother’s blood does not mix with the fetus’s blood.
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The exchange happens through the placental barrier, where the chorionic villi of the placenta come into close contact with maternal blood. Nutrients and gases diffuse across this barrier, allowing for exchange while maintaining separate circulatory systems.
Step 13
Identify the phase of meiosis illustrated above.
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The phase illustrated in the diagram is Anaphase.
Step 14
Give a reason for your answer to QUESTION 3.3.1.
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In Anaphase, the sister chromatids are pulled apart towards opposite poles of the cell.
Step 15
Name the error occurred during the anaphase phase of meiosis.
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The error during this phase is called Chromosomal non-disjunction, where chromosomes fail to separate properly.
Step 16
Draw a diagram of the cell above as it would appear during metaphase 1.
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A diagram of a cell during metaphase 1 would show homologous chromosomes lined up at the equatorial plate with paired chromosomes in alignment.
Step 17
State TWO objectives of the sugar tax proposed for 2017.
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To generate additional funds towards improving the quality of health care.
To reduce the consumption of sugars per day through price increase.
Step 18
Describe how diabetes could adversely affect the productivity of labour as well as the economy of South Africa.
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Diabetes can lead to impaired productivity due to health complications, slow recovery times, and increased medical expenses, ultimately affecting workers' availability and economic output.
Step 19
Which lens (A or B) is adjusted to accommodate distant vision?
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Lens A is adjusted to accommodate distant vision.
Step 20
Which numbered part regulates the amount of light entering the eye?
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Part 2 regulates the amount of light entering the eye.
Step 21
What part can be damaged permanently if laser beams are directed towards it?
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The Retina can be permanently damaged if laser beams are directed towards it.
Step 22
Explain how the changes from A to B were brought about.
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The changes from A to B involve the ciliary muscles contracting, which decreases the tension on the suspensory ligaments, allowing the lens to become thicker for near vision.
