NAME: Section A: 20 Multiple Choice Questions /20 Marks Circle the best alternative on the answer sheet provided. Answer all questions. Section B: 8 Short Answer Questions /40 Marks Answer all questions in the spaces provided. Total Marks Available: / 60 Marks = % = NAME: Total: /20
PART A: MULTIPLE CHOICE SECTION Please circle the most appropriate response on the answer sheet provided. (20 questions - 20 marks) 1. Australia is believed to have once been part of a giant land mass that comprised all of the land on Earth. This giant land mass is now known as: a. Australasia. b. Gondwana. c. Laurasia. d. Pangaea. 2. Variation within a species can occur by: a. mutation. b. pure chance. c. the production of gametes. d. fertilisation of ova by sperm. e. all of the above. f. none of the above 3. What term is used to describe evolution in which two or more species share a common ancestor? a. Phyletic b. Divergent c. Parallel d. Convergent 4. Why is penicillin no longer as effective at controlling bacteria as it was sixty years ago? a. The mould strain the penicillin comes form has become weaker over time b. The penicillin mould has evolved to produce less penicillin c. Bacteria have evolved to be resistant to penicillin d. Other antibiotics have been developed Page 2 of 14
5. The diagram below shows the genetic change in primates as they have evolved. According to this diagram, which pair of species are the most genetically alike? a. Chimps and humans b. Bonobos and chimps c. Gorillas and humans d. Gorillas and chimps 6. Why has evolution resulted in antibiotic resistance in bacteria? a. Bacteria have learnt how to neutralize the effects of the antibiotic and they pass this onto their offspring. b. Bacteria resistant to the antibiotic survive to pass on this characteristic to their offspring. c. Not completing a course of antibiotics allows resistant bacteria to develop. d. Bacteria change their metabolism to cope with the presence of antibiotics. 7. Which one of the following scientists first suggested that populations of organisms could change over time and that changes acquired within the lifetime of the individual could be passed onto its offspring? a. Alfred Wallace b. Alfred Wegener c. Jean-Baptiste Lamarck d. Charles Darwin Page 3 of 14
8. The following statements (not in correct order) summarise the steps in natural selection. 1. Some individuals are better suited to a particular environment 2. Over time there is an increase in particular characteristics in the population 3. There is variation within a population, some of which is genetic 4. Individuals better suited to the environment are more successful at survival and reproduction The order of statements which best describe natural selection are: a. 1, 3, 2, 4 b. 3, 1, 4, 2 c. 2, 3, 1, 4 d. 1, 2, 4, 3 9. In which of the following situations would evolution by natural selection be slowest for an interbreeding population of organisms? a. b. c. d. Migration Selection pressure Variation due to gene mutation absent low low absent high high high low high high high high 10. The number of chromosomes in the nucleus of a human body cell are: a. 2 b. 23 c. 4 d. 46 11. The cells of an apple tree contain 34 chromosomes. What will be the product of meiosis in the apple? a. 2 cells, each with 34 chromosomes b. 2 cells, each with 17 chromosomes c. 4 cells, each with 34 chromosomes d. 4 cells, each with 17 chromosomes Page 4 of 14
12. Which of the following groups of scientists won the Noble Prize for discovering the structure of DNA? a. Chargaff, Franklin and Wilkins b. Franklin, Watson and Crick c. Miescher, Franklin and Watson d. Watson, Crick and Wilkins 13. Complementary base pairing is when a. Only identical bases pair up b. Thymine links with Uracil c. Adenine can link with either Uracil or Thymine d. Guanine links with Thymine 14. Karyotyping is a process whereby a. Alleles are sorted according to size b. Genes are sorted according to size c. Genetic mutations can be marked on chromosomes d. The number of chromosomes can be counted 15. What can be concluded on the basis of the following karyotype? a. Female with a normal set of chromosomes b. Female with Down syndrome c. Male with a normal set of chromosomes ribosome d. Male with Down syndrome Page 5 of 14
16. A gene mutation is a. A change in the base sequence of DNA b. A change in the number of chromosomes c. A failure in the process of meiosis d. Due to non-disjunction 17. With sex-linked (X-linked) genes a. Both males and females are carriers b. Only females are carriers c. Only males are affected d. Only twins are affected 18. Huntington s disease is caused by a dominant allele that is not sex linked. If the father has one copy of the allele and the mother no copies, what is the chance that their children will have the disease? a. 100% b. 25% c. 50% d. 0% 19. Petal colour in snap dragons exhibits co-dominance. What are the possible outcomes when red-flowered snapdragons are crossed with white-flowered snapdragons? a. 2 phenotypes: red and white b. 2 genotypes: red and white c. 3 phenotypes: red, white and pink d. 3 genotypes: red, white and pink 20. A woman has one recessive sex linked haemophilia allele and one normal allele. Which of the following are true? a. All of her daughters will have the same genotype as herself b. She is a carrier for the haemophilia allele c. She will develop haemophilia d. The probability of passing the haemophilia allele to her son is 100% Page 6 of 14
PART B: SHORT ANSWER SECTION Answer all questions in the spaces provided. (8 questions 40 marks) 1. Explain the differences between analogous structures and homologous structures. Provide an example to help your explanation of each type. (Total = 4 marks) 2. (a) Provide two examples of different types of fossils. [2] (b) Explain why the fossil record is incomplete. [2] (Total = 4 marks) Page 7 of 14
3. The following population of seabirds shows variation with respect to beak shape. Discuss how natural selection may act on this population in the future. (Total = 6 marks) Page 8 of 14
4. The tree diagram (cladogram) below shows how closely related a group of species of spiders are on the Hawaiian island group. Two of the species have not been given a scientific name. Three pairs of the spiders spin very similar webs. These are shown on the diagram. The island on which the spider lives is also indicated. location: T. laboriosa - Mainland - USA T. hawaiensis emerald ovoid T. limu - Hawai i - O ahu - O ahu eurylike - O ahu T. acuta - Maui T. fliciphilia - Maui T. stelarobusta - Maui T. eurychasma T. perkinsi - Maui - Hawai i [Source: T A Blackledge and R G Gillespie (November 2004), Proceedings of the National Academy of Sciences, 101, (46),pages 16228-16233] Page 9 of 14
(a) State which species is most distantly related to T. perkinsi on the basis of the tree diagram. [1] (b) Explain the evidence in the diagram for a. convergent evolution. [1]......... b. adaptive radiation. [1]...... (Total = 3 marks) Page 10 of 14
5. Answer the following questions regarding the structure of DNA: (a) What are the subunits of the DNA molecule called? [1] (b) What are the 3 components of a DNA subunit? [3] (c) What is the name given to the shape of a DNA molecule? [1] (d) State the type of bonds that i. connect the two strands of a DNA molecule. [1]... ii. link DNA subunits into a single strand. [1]... (e) Explain why there are two different types of chemical bonds needed within the DNA molecule. [2] (Total = 9 marks) Page 11 of 14
Questions 6-7 are related to inheritance. Please remember to show a key and to show all of your working. 6. Galactosemia is a rare genetic disorder that affects an individual's ability to metabolise the sugar galactose properly. Galactosemia is an autosomal recessive trait. (a) Using a punnet square, determine the chance of a mother (who is a carrier of Galactosemia) and a father (who has Galactosemia) having a child without the condition. [3] (b) Galactosemia affects about 1 per 60,000 births for people of European ancestry. In other populations the incidence rate differs. Discuss why different disorders have different rates of incidence in different countries and in different racial groups. [2] (Total = 5 marks) Page 12 of 14
7. In humans, blood type is controlled by multiple alleles. There are 4 possible blood types: A, B, AB and O. (a) Construct a pedigree chart to show a type O man and a homozygous type A woman and their two female children. [2] (b) One of these children marries a type B person. Is it possible for this child to have type O blood. Explain. [2] (Total = 4 marks) Page 13 of 14
8. Duchenne muscular dystrophy (DMD) is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration and eventual death. (a) What is meant by sex-linked inheritance. [1] (b) If a carrier female of DMD has a child with a normal male, determine the possible genotypes and phenotypes of their offspring. [4] (Total = 5 marks) Page 14 of 14