Exam code: 3400
Image 6 shows the stages of genetically modifying a soya bean crop plant to become herbicide resistant.
Image 6
Use Image 6 to describe what is happening in each of the stages 1–7 during the process of genetic modification.
Include one advantage and one disadvantage of genetically modified (GM) crops in your answer
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Image 7.1 shows a set of chromosomes from a human male body cell.
Image 7.1
(i) State the number of chromosomes in a human body cell.
[1]
(ii) Draw a circle around the sex chromosomes in Image 7.1.
[1]
Images 7.2A and 7.2B show male and female lions.
(i) Complete the Punnett square below to show possible offspring when the male lion (XY) and the female lion (XX) mate.
[2]
(ii) State the expected ratio of male:female lions in the offspring.
[1]
(iii) State whether it is the male or female lion that determines the sex of the offspring. Explain your answer.
[2]
Lions have 38 chromosomes in their body cells.
(i) State how many chromosomes there are in a sex cell of a lion.
[1]
(ii) State the scientific name for sex cells.
[1]
(iii) Name the type of cell division that produces sex cells.
[1]
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Image 3.1 shows part of a DNA molecule.
(i) Complete the labels on Image 3.1 by choosing words from the box.
[3]
phosphate salt base sugar amino acid |
(ii) The shape of DNA is described as a twisted ladder. State the scientific term for this shape.
[1]
The DNA of an individual can be analysed as a genetic profile.
Underline which one of the following correctly states how the DNA must first be treated in order to produce the bands in a genetic profile.
Cut it into small pieces.
Place it in acid conditions.
Expose it to very low temperatures.
Image 3.2 shows the DNA profiles of people involved in a paternity test.
Image 3.2
(i) In this baby’s profile, three of the bands have come from the mother and three from the father.
Draw circles around the three bands in the baby’s profile in Image 3.2 which have come from the mother.
[1]
(ii) Use the DNA profiles to conclude which man (A, B or C) is the baby’s father. Explain how you obtained your answer.
[2]
(iii) Apart from paternity testing state one other use for DNA profiling.
[1]
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(i) A woman, who is a carrier of the HFE mutation, and a man, who is affected by the condition are expecting a child.
Complete the Punnett square below to show the possible genotypes of their child. Use H to represent the normal allele.
[4]
Woman Man
Phenotype............................................... ×..................................................
Genotype …….....................………………………. × …….....................……………………….
(ii) State the probability of the couple having a child affected by haemochromatosis.
[1]
Probability = ...........................................................
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Hair length in cats is controlled by a pair of alleles. The allele for short hair (H) is dominant to the allele for long hair (h).
State what is meant by the terms:
(i) allele;
[1]
(ii) dominant;
[1]
(iii) recessive.
[1]
(i) A cat breeder crossed a homozygous short-haired cat with a long-haired cat. Complete the Punnett square to show the predicted genotypes of the offspring. Use the letters H and h for the alleles.
[2]
Gametes | ||
(ii) State the phenotype of the offspring in the F1 generation.
[1]
(iii) Complete the Punnett square to show the possible genotypes of the offspring if two of the F1 offspring were crossed.
[2]
Gametes | ||
(iv) Using the results from (b)(iii), state how many kittens would be predicted to be short-haired in a litter of 8 kittens.
[1]
(v) The cat breeder wanted to determine whether one of the short-haired cats was homozygous or heterozygous. She decided to breed the short-haired cat with a long-haired cat. Predict the phenotypes of the offspring you would expect if the short-haired cat was:
I. Homozygous
[1]
II. Heterozygous
[1]
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There are many different types of cancer. One of the most common is breast cancer. In approximately 30% of breast cancers a high level of HER2 protein is present, this is due to a mutation in the HER2 gene. The high level of HER2 protein found on the surface of the cells causes them to grow and divide excessively.
(i) In Wales, approximately 2900 people are diagnosed with breast cancer each year. Calculate how many of those diagnosed would be expected to have a high level of HER2 protein present.
[2]
Number of people = ...............................................
(ii) Explain how the HER2 gene codes for the production of HER2 protein.
[3]
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