Practice exam paper (1)

List two inherited characteristics in human beings. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Label the structures. Use the following terms: Cell membrane Centromere Chromatid Chromosome DNA Gene Nuclear envelope Name the four bases in DNA. ………………………………………………………………………………………………………………………………………………. Which 2 base pairs are formed? ………………………………………………………………………………………………………………………………………………. List at least 3 differences between mitosis and meiosis? Mitosis Meiosis What process takes place in ribosomes? Replication Transcription Translation Mitosis At what stage of meiosis does the following take place? Interphase Prophase I Metaphase I Prophase II Give the definition of cancer: ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Most humans (except identical twins) have a unique set of chromosomes. This results in each individual having a unique phenotype (appearance). Describe 2 processes that have caused this variation in humans. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Norma attends ISE. She does a survey on the hair colours of all the students in MP2. Her results are shown in the chart. Is hair colour an inherited or acquired characteristic? Explain your answer. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Is hair colour continuous or discontinuous variation? Explain your answer. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… What is the least common hair colour in the year group? ………………………………………………………………… How many students were examined in the survey? ……………………………………………………………….. Norma reads some reliable information that suggests that less than 30% of the Dutch population have blonde hair. What percentage of Norma’s year group has blonde hair? Show your working. …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………... Suggest some reasons why the percentage of blonde hair for Norma’s year group is quite different from the national value. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… In which stage in meiosis is the chromosome number reduced from diploid to haploid? During pairing of chromosomes in the first division of meiosis During pairing of chromosomes in the second division of meiosis When chromosomes move to opposite ends of the cell during the first division of meiosis When chromosomes move to opposite ends of the cell during the second division of meiosis The pattern of inheritance of sex-linked genes is the same in Drosophila as in humans. Eye colour in Drosophila is controlled by a sex-linked gene. The allele for red eye is dominant over the allele for white eye. A red eyed male mates with a white eyed female. Which eye colours are found in the offspring? What is a difference between autosomes and sex chromosomes? Autosomes are not found in gametes but sex chromosomes are. Sex chromosomes are found in animal cells and autosomes are found in plant cells. Autosomes are diploid and sex chromosomes are haploid. Sex chromosomes determine gender and autosomes do not.  17. (a) State one example of sex linkage. .................................................................................................................................... (c) Draw a simple pedigree chart that clearly shows sex linkage in humans. Use conventional symbols. Start with an affected woman and an unaffected man. 18 Explain how the inheritance of chromosome 21 can lead to Down’s syndrome. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... 19. Chiwawas have a gene for coat length: a smooth or a long coat. The smooth coat allele is dominant over the long coat allele. Can you explain how a smooth coated and a long coated chiwawa can have long coated puppies? Use a Punnett square to explain your answer. 20.  MP5 practise genetics exam