Unit 2 Physiology and Health Part (a) The Reproductive System HOMEWORK BOOKLET Name: Homework Date Due Mark % Key Area 1 The structure and function of reproductive organs Key Area 2 Hormonal control of reproduction Key Area 3 The Biology of controlling fertility Key Area 4 Antenatal and Postnatal screening MCQ: /4 Section B: /15 TOTAL: /19 MCQ: /4 Section B: /23 TOTAL: /27 MCQ: /5 Section B: /9 Essay: /8 TOTAL: /22 MCQ: /8 Section B: /17 Essay: /8 TOTAL: /33
Key Area 1 The structure and function of reproductive organs 1. A function of the interstitial cells in the testes is to produce A. sperm B. testosterone C. seminal fluid D. follicle stimulating hormone (FSH). 2. As an ovum develops within the ovary, it is surrounded by A. Follicle B. seminal fluid C. endometrium D. a corpus luteum 3. The diagram below shows a cross-section of a testis. Which of the labelled cells can produce testosterone? Questions 4 and 5 refer to the graph below 4. The sperm counts of a sample of men taken between 1940 and 2000 are shown in the graph below. What is the average reduction in sperm count per year? A. 0 67 million/cm 3 /year B. 0 75 million/cm 3 /year C. 0 92 million/cm 3 /year D. 45 million/cm 3 /year Page 2
5. Calculate the percentage decline in sperm count over the 60 year period Space for working % 1 6. Prostate-specific antigen (PSA) is a chemical produced by cells within the prostate gland. PSA is secreted into the seminal fluid where it thins the fluid, making it less viscous. (a) Explain why it is important that the seminal fluid is less viscous. 1 (b) Increased levels of PSA can be detected in the blood plasma of men with prostate cancer. (i) Suggest why the presence of cancer in the prostate gland would lead to increased production of PSA. 1 (ii) Describe how prostate cancer can lead to the development of secondary tumours. 2 Page 3
7. The diagram below shows events that occur during human reproduction. (a) Identify processes X, Y, and Z X Y Z 3 (b) Complete the diagram by entering the name of cell E. 1 Page 4
8. The flowchart summarises the processes involved in the production of semen. ICSH (a) Name hormone X and tissue Y. Hormone X Tissue Y 2 (b) Semen contains substances secreted by structure Z. (i) Identify structure Z. 1 (ii) Describe the role of the secretions from the seminal vesicles and structure Z. 1 Page 5
9. The diagrams below show sections through two structures found in the ovary at different times in the menstrual cycle. (a) Name structures P and Q. P Q 1 (b) What key event in the menstrual cycle occurs before P develops into Q? 1 [END OF HOMEWORK] Page 6
Key Area 2 Hormonal control of reproduction 1. The graph below shows changes in the concentration of hormones X and Y in the blood during the menstrual cycle. Which of the following correctly identifies hormones X and Y? 2. Changes in the ovary during the menstrual cycle are described below. 1 Corpus luteum forms 2 Ovulation occurs 3 Progesterone is produced 4 Corpus luteum degenerates 5 Follicle develops The sequence in which these changes occur following menstruation is A. 2, 3, 1, 5, 4 B. 2, 1, 3, 4, 5 C. 5, 3, 2, 1, 4 D. 5, 2, 1, 3, 4. Page 7
3. The diagram below illustrates the hormonal control of a 30-day menstrual cycle Which line of the table correctly identifies hormone Z, and the structure which produces this hormone? 4. The diagram below represents part of the mechanism which controls ovulation. Page 8
5. The diagram below represents sperm production in a cross section through part of a testis. (a) Name structure A. 1 (b) Describe two ways that the pituitary gland stimulates sperm production in structure A. 1. 1 2. 1 6. The diagram below shows a germline cell dividing to produce sperm cells. (a) Name this type of cell division 1 (b) State the number of chromosomes present in a sperm cell. 1 Page 9
7. The diagram below shows the fertilisation of an ovum and its subsequent early development. (a) Name structures A and B. A B 2 (b) The ovum is released from a follicle in the ovary which then becomes the corpus luteum. These structures are affected by pituitary hormones. Complete the table below to describe the effect of these hormones on the structures. (c) Explain what prevents the further development of follicles when an embryo is developing in the uterus. 2 Page 10 2
8. The graph below shows the concentration of two ovarian hormones in a woman s blood during her menstrual cycle. (a) Name hormone X 1 (b) What effect does oestrogen have on the following structures? i. The uterus between days 4 and 12 in the cycle. 1 ii. The pituitary gland on day 12 of the cycle. 1 (c) Suggest one way in which the graph would be different if the woman became pregnant during this cycle. 1 Page 11
9. The graphs below show the plasma concentrations of certain hormones throughout a woman s menstrual cycle. Graph 1 shows the concentrations of FSH and LH. Graph2 shows the concentration of two other hormones, X and Y. Page 12
(a) Where in the body are FSH and LH produced? 1 (b) Name hormones X and Y. X Y 2 (c) What is the maximum concentration of hormone Y? 1 (d) On which day did ovulation occur? Give a reason for your answer. Day Reason 2 (e) During her next cycle, the woman became pregnant. Describe any differences which would occur in the concentrations of FSH and hormone Y after day 25. 2 [END OF HOMEWORK] Page 13
Key Area 3 The Biology of controlling fertility 1. The table below contains information about four semen samples. Which sample has the highest number of active sperm per cm 3? 2. In fertility clinics, samples of semen are collected for testing. The table below shows the analysis of semen samples taken from five men. A man is fertile if his semen contains at least 20 million sperm cells/cm 3, and at least 60% of the sperm cells are active and at least 60% of the sperm cells are normal. The semen samples that were taken from infertile men are: A. samples 3 and 4 only B. samples 2 and 4 only C. samples 2, 3 and 4 only D. samples 1, 2, 4 and 5 only 3. Which of the following forms of contraception causes thickening of the cervical mucus? A. Mini-pill B. Barrier methods C. Morning-after pill D. Intra-uterine device Page 14
4. The effects of two human hormones, P and Q, on human sperm production are shown in the graph below. A possible conclusion from the graph is that when the level of: A. hormone P is high and hormone Q is high, sperm production is low B. hormone P is low and hormone Q is low, sperm production is low C. hormone P is low and hormone Q is high, sperm production is high D. hormone P is high and hormone Q is low, sperm production is high 5. Which of the following changes indicate ovulation is likely to have taken place? Cervical mucus Body Temperature A becomes sticky rises B becomes sticky falls C becomes watery rises C becomes watery falls Page 15
6. The diagrams show the hormonal control of the testes and ovaries by the pituitary gland. (b) (i) Identify hormones A, B, and C. A B C 3 (ii) State an effect of oestrogen on the pituitary gland, other than that shown above. 1 (c) Where in the testes is testosterone produced? 1 (d) Distinguish between cyclical fertility and continuous fertility 1 Page 16
(e) The female contraceptive pill raises the levels of ovarian hormones in the blood. Explain why this has a contraceptive effect. 2 (f) During IVf treatment, it is possible to detect single gene disorders in fertilised eggs before they are implanted into the mother. What term describes this procedure? 1 Page 17
7. Discuss procedures that can be used to treat infertility (8 marks) Page 18
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Key Area 4 Antenatal and Postnatal Screening 1. As part of antenatal screening, an ultrasound scan can be carried out. The length of the developing fetus is measured to monitor growth. The graph below shows the length of a human foetus before birth. What is the percentage increase in length of the foetus during the four months before birth? A. 33.3% B. 37.5% C. 60.0% D. 150% 2. Which of the following babies would be most likely to require a blood transfusion immediately after birth? A. The first baby of a Rhesus negative mother and a Rhesus positive father B. The first baby of a Rhesus positive mother and Rhesus negative father C. The second baby of a Rhesus negative mother and Rhesus positive father D. The second baby of a Rhesus positive mother and Rhesus negative father 3. The gene (m) which causes one type of muscular dystrophy is sex-linked and recessive to the normal gene (M). If a carrier female and an unaffected male have children, what would be the predicted effect on their sons and daughters? Page 20
4. The family tree below shows the transmission of the Rhesus D-antigen. The gene for the Rhesus D-antigen is not sex-linked. The parents are expecting a fourth child. What is the chance that this child will be Rhesus negative? A. 0% B. 25% C. 50% D. 100% 5. Phenylketonuria is caused by a single autosomal gene. A man and a woman, who are unaffected, have an affected child. What is the probability that their next child will be affected? A. 25% B. 50% C. 75% D. 100% 6. The transmission of a gene for deafness is shown in the family tree below. This condition is controlled by an allele which is A. dominant and sex-linked B. recessive and sex-linked C. dominant and not sex-linked D. recessive and not sex-linked Page 21
7. Familial hypercholesterolaemia (FH) is caused by an autosomal dominant allele. The family history below shows the inheritance of FH through three generations. Which individual confirms that this condition is autosomal? 8. In which of the following situations might a fetus be at risk from Rhesus antibodies produced by the mother? Father Mother A Rhesus positive Rhesus negative B Rhesus positive Rhesus positive C Rhesus negative Rhesus positive D Rhesus negative Rhesus negative Page 22
9. The diagram below shows the main stages in the production of a karyotype of fetal chromosomes. (a) Name the process described in stage 1. 1 (b) State one feature of chromosomes which enables them to be arranged into a karyotype. 1 (c) Give one piece of information which can be obtained from the examination of fetal karyotypes. 1 Page 23
10. Cystic fibrosis is a genetic disorder caused by the inheritance of recessive alleles. The expression of these alleles causes excess mucus in the digestive tract and lungs. (a) The family tree illustrates the incidence of cystic fibrosis in a family. 2 1 1 Page 24
11. Duchenne s muscular dystrophy is an inherited condition in which muscle fibres gradually degenerate. The condition is sex-linked and caused by a recessive allele. The family tree below shows the inheritance of the condition through three generations of a family. (a) (i) What percentage of the grandsons have muscular dystrophy? 1 (ii) Sisters T and U each go on to have a son. For each sister, state the percentage chance of her son having muscular dystrophy. Son of T Son of U 2 (b) Where conditions such as Duchenne s muscular dystrophy exist in a family, the family history can be used to determine the genotypes of its individual members. What term is used for this process? 1 Page 25
(c) An individual with Duchenne s muscular dystrophy cannot make dystrophin. Dystrophin is an essential muscle protein coded for by a gene, when this gene is altered, dystrophin is not produced. (i) What general term is used to describe a gene alteration? 1 (ii) How might the structure of the gene which codes for dystrophin be altered? 1 Page 26
12. The diagram below shows the inheritance of a sex-linked condition in a family. The condition is caused by a recessive allele. (a) (i) Explain why individual 1 could not pass the condition to his sons. 1 (b) Individual 6 has a son with a woman who is a carrier of the condition. Calculate the percentage chance of their son having this condition. Space for working % 1 (c) The condition is caused by a mutation in which an extra nucleotide is inserted into the gene that codes for an enzyme. Explain the likely effect of this mutation on the structure of the enzyme. 1 (d) The condition occurs with a frequency of 1 in 350 males. Assuming an equal proportion of males and females in the population, calculate how many males are likely to have the condition in a town with a population of 175,000. Space for working Page 27 % 1
13. Discuss the screening and testing procedures which may be carried out as part of antenatal care (8 marks) Page 28
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