T3-1
[202 marks]
[1 mark] 1. The feather colour of a certain breed of chicken is controlled by codominant alleles. A cross between a homozygous black-feathered chicken and a homozygous white-feathered chicken produces all speckled c hickens. What phenotypic ratios would be expected from a cr oss between two two speckled chickens? A. All speckled B. 1 black feathers : 1 white feathers C. Speckled, black feathers and white feathers in equal numbers D. 1 black feathers : 2 speckled feathers : 1 white feathers
2. The presence of freckles is a characteristic controlled by a dominant gene. Two parents who are heterozygous for [1 mark] the characteristic have three childre n, all of whom have freckles. Which statement is true if they have a fourth child? A. There is a 100 % chanc e that their next child will have freckles. B. There is a 75 % chanc e that their next child will have freckles. C. There is a 50 % chance that their next child will will have freckles. D. The next child will ha ve no frec kles as the ratio is 3 with freckles to 1 without freckles.
3.
What maximum number of diffe rent genotypes and phenotypes are possible among the childre n of a mother with [1 mark] blood group A and a father with blood group B?
4.
Which process can be used to ampl ify small fragments of DNA? A. Gel electrophoresis B. Polymerase chain reaction C. DNA profiling D. Electron microscopy
[1 mark]
5.
If a man with blood group O and a woman with blood group AB ha ve children, which blood gro up(s) could the children have? A. Group O only B. Groups A and B only C. Group AB only D. Groups O, A, B and AB
[1 mark]
6.
Which individuals are co lour blind in this Punnett grid?
[1 mark]
A. XB Y B. XB XB C. Xb Y
7.
What is a possible source of the chromosome s used for pre-natal karyotype diagnosis? A. The mo ther’s lymphocytes B. The mother’s cheek cells C. The cells from chorionic villi D. The fetal hair root cells
[1 mark]
8.
What was an aim of genetic modification o f organisms? A. To provide stem cells from embryos for medical use B. To make cro p plants resistant to herbicides C. To provide sperm c ells for in vitro fertilization (IVF) D. To produce genetically identical sheep
[1 mark]
9.
What causes the presence of three chrom osomes 21 in Down syndrome? A. Crossing over B. Allele change C. Non-disjunction D. Gene mutation
[1 mark]
The image shows data data collected in order to determine the paternity of a child.
10a. State the name of the process used to produce the pattern of bands seen in the image .
[1 mark]
7.
What is a possible source of the chromosome s used for pre-natal karyotype diagnosis? A. The mo ther’s lymphocytes B. The mother’s cheek cells C. The cells from chorionic villi D. The fetal hair root cells
[1 mark]
8.
What was an aim of genetic modification o f organisms? A. To provide stem cells from embryos for medical use B. To make cro p plants resistant to herbicides C. To provide sperm c ells for in vitro fertilization (IVF) D. To produce genetically identical sheep
[1 mark]
9.
What causes the presence of three chrom osomes 21 in Down syndrome? A. Crossing over B. Allele change C. Non-disjunction D. Gene mutation
[1 mark]
The image shows data data collected in order to determine the paternity of a child.
10a. State the name of the process used to produce the pattern of bands seen in the image .
[1 mark]
10b. Determine, with a reason, which male is the father of the child.
[1 mark]
Malaria is a mosquito-borne disease caused by a unicellular organism, Plasmodium . Plasmodium is a parasite that spends part of its life in a mosquito and part in a human. The mo squito transmits the Plasmodium to a human when it feeds on human blood. Mosquitoes hatch in water and a re flying insects as adults. In the country of Belize, where malaria is a serious problem, studies have been made to determine what environmental factors affect the incidence of the disease. 156 villages were studied over a ten-year period.
11a.
State the district where there is the highest number of villages with the highest incidence of malari a.
[1 mark]
11b. Analyse the data in the map to find whether there is an association between rivers and the incidence of malar ia.[2 marks]
Each of the six districts of Belize was studied from 1989 to 1999. The graph shows the mean number of people in each district to be affected by malaria per year per 1000 people.
11c. Compare the trends in incidence of malaria for Toledo and Corozal.
[3 marks]
11d. Suggest a reason for the decreases in the incidence of malaria from 1995 to 1999.
[1 mark]
11e. Suggest a reason why the incidence of mala ria is so low in the Belize District.
[1 mark]
The country of Belize has many different ecosystems. These ecosystems are shown in the bar chart. The white bars indicate the total area within each ecosystem with the lowest incidence of mala ria. The dar k grey bars indicate the total area within each ecosystem with the highest incidence of m alaria. The total area with an intermediate incidence of malaria is not shown.
11f. Besides farmland, identify which two ecosystems have the greatest total area with a high incidence of ma laria.
[1 mark]
11g. Predict with a reason, using the data, which district has most farmland.
[1 mark]
11h. Discuss whether malaria could be reduced by replacing farmland with natural ecosystems and replacing broadlea f hill forest with mixed hill forest.
[4 marks]
12a. Meiosis in humans produces cells that participate in fertilization. Outline the processes involved in meiosis.
[5 marks]
12b. Following fertilization, cells in the developing embryo diffe rentiate. Outline a technique for cloning using differentiated animal cells.
[5 marks]
12c. Discuss ethical issues of therapeutic cloning in humans.
[8 marks]
13a. Outline the cell theory.
[2 marks]
13b. Annotate the electron micrograph of the Escherichia coli cell with the function of the indi cated structure.
[1 mark]
13c. Calculate the magnification of the electron micrograph.
[1 mark]
13d. Explain the role of the follo wing enzymes in DNA replication. Helicase
[1 mark]
13e. Explain the role of the follo wing enzymes in DNA replication. DNA ligase
[1 mark]
14a. Define linked genes.
[1 mark]
[3 marks] 14b. In cats, the allele for curled ears (C) is dominant over the allele for normal ears (c). The allele for black colour (B) is dominant over the allele for gr ey colour (b). A cross occurs between two cats that are both heterozygous for these unlinked traits.
Using a Punnett grid, predict the ratio of phenotypes of o ffspring in the next generation.
15a. Explain chemiosmosis as it occurs in photophosphorylation.
[8 marks]
15b. Draw an anno tated graph of the e ffects of light intensity on the rate of photosynthesis.
[4 marks]
15c. Using a named example of a genetically modified c rop, discuss the specific ethical issues of its use.
[6 marks]
16a. Draw a labelled diagram of the human adult male reproductive system.
[5 marks]
16b. Describe the application of DNA profiling to determine paternity.
[5 marks]
16c. Explain the inheritance of colour blindness.
17. What is a characteristic of the human Y chromosome?
[8 marks]
[1 mark]
A. It is made of DNA and histones covered by phospholipids. B. It contains some genes that are not present on the X chromosome. C. It is the largest chromosome in the human karyotype. D. It has a condensed length of approximately 100 µm.
18. What is a definition of a clone? A. A group of cells derived from a single parent cell B. Differentiated cells that retain the c apacity to divide C. A fetus developed specifically for medical use D. A group of cells that have lost the ability to differentiate
[1 mark]
19. What was an aim of genetic modification o f organisms?
[1 mark]
A. To provide stem cells from embryos for medical use B. To make cro p plants resistant to herbicides C. To provide sperm cells for in vitro fertilization (IVF) D. To produce genetically identical sheep
20a. Outline the processes that occur duri ng the first division of meiosis.
[6 marks]
20b. Prior to cell division, chromo somes replicate. Explain the process of DNA replic ation in prokaryotes.
[8 marks]
20c. Outline outcomes of the human genome project.
21a.
Describe the process of blood clotting.
[4 marks]
[4 marks]
[6 marks] 21b. Factor IX is a blood clotting protein which some hemophiliacs lac k. In the future hemo philia could be treated using clotting factors synthesized by ge netically mo dified bacteria. Outline the basic technique used for this gene transfer.
21c. Explain how males inherit hemophilia and how females can become carrier s for the condition.
[8 marks]
22a. In a strain of soybeans, high oil content (H) in seeds is dominant to low oil content (h) and four seeds in a pod (F) [1 mark] is dominant to two seeds in a pod (f). A farmer cr osses two soybean plants, both with high oil content and four seeds in a pod. The offspring have a phenotypic ratio of 9 : 3 : 3 : 1. Identify the genotypes of the soybean plants with high oil content and four seeds in a pod that were used in the cross.
22b. In a strain of soybeans, high oil content (H) in seeds is dominant to low oil content (h) and four seeds in a pod (F)[2 marks] is dominant to two seeds in a pod (f). A farmer cr osses two soybean plants, both with high oil content and four seeds in a pod. The offspring have a phenotypic ratio of 9 : 3 : 3 : 1. Determine the geno types of the gametes and offspring using a Punnett grid.
22c. In a strain of soybeans, high oil content (H) in seeds is dominant to low oil content (h) and four seeds in a po d (F)[2 marks] is dominant to two seeds in a pod (f). A farmer cr osses two soybean plants, both with high oil content and four seeds in a pod. The offspring have a phenotypic ratio of 9 : 3 : 3 : 1. Identify the phenotypes of each part of the phenotypic ratio.
The image shows the karyotype of a person who developed as a female.
22d. Deduce the reason for the person developing as a female.
[1 mark]
22e. Determine, with a rea son, whether this karyotype shows that non-disjunction has occ urred.
[1 mark]
23. What term describes the failure of sister chromatids to separate during ana phase II?
[1 mark]
A. Sex linkage B. Karyotyping C. Non-disjunction D. Semi-conservative replication
24. What information can be concluded from the karyotype?
[1 mark]
A. The person is a normal male. B. The person is a normal female. C. The person is a male with Down syndrome. D. The person is a fema le with Down syndrome.
25.
In humans the ABO blood groups are an example of inheritance involving multiple alleles. In a family the parents [1 mark] have blood group A and blood group B re spectively. Their first child has blood group O. What is the probability that their next child will have blood group B? A. 100 % B. 75 % C. 50 % D. 25 %
26. Alkaptonuria is an inheri ted condition in humans that affects phenylalanine and tyrosine metabolism, resulting in [1 mark] the production of black-coloured urine. What deduction can be made about the allele for this condition from the pedigree chart?
A. It is autosomal dominant. B. It is autosomal recessive. C. It is X-linked recessive. D. It is Y-linked recessive.
27. One type of gene mutation involves a base substitution.
What are the conseque nces of the base substitutions in the two new sequences o f DNA? A. Both are mutations that would result in differ ent polypeptides. B. Sequence 2 would re sult in a changed polypeptide but sequence 1 would not. C. All three DNA sequences would translate into the same polypeptide. D. Only the original DNA and sequence 2 would translate into the same polypeptide.
[1 mark]
28. Which genetic condition can be diagnosed by karyotyping?
[1 mark]
A. Trisomy 21 B. Sickle-cell anemia C. Hemophilia D. Colour blindness
29.
The diagram shows a pedigree.
According to the pedigr ee shown, which pattern of inher itance is indicated? A. Sex-linked recessive trait B. Autosomal recessive trait C. Autosomal dominant trait D. Codominant alleles
[1 mark]
30. If a father with A-type blood a nd a mother with B-type blood have a c hild, what is the probability that the child will [1 mark] have O-type blood? A. 50 % chance if both parents have the recessive allele . B. 25 % chance if both parents have the recessive allele . C. 0 % chance because neither parent has the allele. D. 50 % chance if either par ent has the recessive allele.
31a. State three processes occurring in a cell duri ng interphase of the cell cycle but not in mitosis.
[3 marks]
1. .................................................................... 2. .................................................................... 3. ....................................................................
31b. Explain how sexual reproduction can allow evolution to occur.
[3 marks]
32a. Define codominant allele, recessive allele, locus and sex linkage.
[4 marks]
32b. ABO blood groups are inherited from parents, but it is possible for a child to have a different blood group from either pare nt. Outline how this can happe n using a Punnett grid.
[6 marks]
32c. Explain how males inherit hemophilia and how females can become carriers for the condition.
[8 marks]
33a. Using the table, state whether rece ssive, dominant and codominant alleles ar e expressed in heterozygous and [2 marks] homozygous genotypes by writing yes, no or both.
33b. State two alleles in blood groups that are codominant.
[1 mark]
[3 marks] 33c. Clouded leopa rds live in tropical ra inforests of South-East Asia. The norma l spots (brown with a black outline) are dom inant and black spots are recessive. The trait is sex-linked. A male with black spots was crossed with a female with normal spots. She had four c ubs, two males and two females. For each sex, one cub ha d normal spots and the other cub had blac k spots.
Deduce the geno type of the mother. Show your work in a Punnett grid.
34a. State the source, substrate, products and optimal pH condi tion for lipase i n the human dige stive system.
[4 marks]
34b. Outline the use of
[6 marks]
named enzymes
in gene transfer using plasmids.
34c. Explain the effect of changes of pH, substrate concentration and temperature on enzyme activity.
[8 marks]
35. A body cell of a goat has 60 chromosomes. What would be produced following meiosis in the testis of a male goat?
[1 mark]
A. 2 cells each with 60 chromosomes B. 4 cells each with 60 chromosomes C. 2 cells each with 30 chromosomes D. 4 cells each with 30 chromosomes
36. Which of the following involves meiosis? A. Tissue repair B. Production of gametes C. Asexual reproduction D. Growth
[1 mark]
37. In guinea pigs black coat colo ur is dominant to white. In a test cross between a blac k and a white guinea pig both [1 mark] black and white offspring were produced. What perce ntage of the offspring would be expected to be white? A. 75 % B. 50 % C. 33.3 % D. 25 %
38. The image shows a human karyotype.
According to the image, what conditions can be determined? A. Non-disjunction has occurred and the individual is male . B. Non-disjunction has occurred and the individual is fema le. C. The individual is female and has Down syndrome. D. The individual is male a nd has Down syndrome.
[1 mark]
39. The diagram shows results of electrophoresis of DNA from a crime scene.
Which suspect could be implicated as the crimina l, according to the gel of D NA shown? A. Suspect 1 B. Suspect 2 C. Suspect 3 D. Suspect 4
[1 mark]
40. What stage of mei osis is shown in the microgra ph?
[1 mark]
A. Prophase I B. Metaphase II C. Anaphase II D. Telophase I
41. What commonly causes Down syndrome in humans? A. Non-disjunction B. Base substitution C. Amniocentesis D. Gene mutation
[1 mark]
42. When genes are transferr ed between species, the amino acid sequence o f the polypeptide translated from them [1 mark] is unchanged. Why is this so? A. All organisms use ribosome s for protein synthesis. B. DNA replication is semi-conservative. C. The enzymes used are substrate specific. D. The genetic code is universal.
43. What is the name given to a heritable factor which controls a speci fic characteristic?
[1 mark]
A. Allele B. Chromosome C. Gene D. Mutation
44. What would be the expected result if a woman carrier for colour blindness and a colour blind man had many children? A. All offspring will be colour blind. B. All male offspring will be colour blind and all females normal. C. All males will be normal and all females will be colour blind. D. All females will be carriers of colour blindness or colour blind
[1 mark]
