GOZO COLLEGE SECONDARY SCHOOL

Transcription

1 GOZO COLLEGE SECONDARY SCHOOL Half Yearly Exams Subject: Biology Form: Year 9 (Form 3) Time: 2 Hours Name: Class: Section A Section B Question No Max mark Actual mark TOTAL MARK Page 1 of 16

2 Section A Answer ALL questions in the space provided. This section carries 55 marks 1. This question is about life processes. A gymnast attends training sessions regularly. The workouts are intense. Gymnasts require a lot of energy when practicing. The choreography done by gymnasts consists of a balance of jumps, leaps and flexibility movements. While performing, gymnasts change their movements in response to changes in the type of music. Sweating and reddening of the skin are two common physical visible symptoms after a training session. Following a balanced diet and drinking lots of water help a gymnast to give a good performance. Write the most appropriate vital function done by the gymnast when:- a. using energy when practicing:- b. doing jumps:- c. sweating:- d. changing movements in response to the different type of music :- e. following a balanced diet: - (Total 5 marks) Page 2 of 16

3 2. The following pictures show specialized animal and plant cells. A B C D E F a. Name the above animal and plant specialised cells. Cell A - Cell C Cell E Cell B- Cell D Cell F b. On the diagram of cell B above name and label the cell organelle which:- i) Controls the passage in and out of cells ii) Is filled with cell sap c. Describe TWO ways to show how cell D is adapted to perform its function. d. Cell E has mitochondria in its middle section. Explain the importance of this. Page 3 of 16

4 e. The table below contains incomplete biological statements about specialised cells. Complete each statement by writing the correct number in the correct box. Statement The number of products produced in a food production process done by cell B is The number of chromosomes in cell C is The number of organelles which are found in Cell D but not in Cell A is Number f. A person has a throat infection. Predict if cell F increases or decreases in number. Prove your prediction by using scientific evidence. (Total 13 marks) 3. A student had a sample of bread with mould on it. The student decided to observe the piece of bread using the light microscope. a. Name a typical mould that the student could have observed. b. Label the six indicated parts of the light microscope which the student used in order to view the mould. Page 4 of 16

5 c. When observing the fungus under the light microscope, the student stated that chloroplasts were present. Do you think that the student s observation was correct? Give a reason for your answer. d. List ONE precaution the student could have used when doing this experiment. (Total 7 marks) 4. The following diagrams are representing methods of transport that are used by different substances to move in and out of cells. a. Write down the letter/s of the picture/s representing the process of :- i) Diffusion ii) Osmosis iii ) Active transport Page 5 of 16

6 b. Put the following phrases in the correct area of the Venn diagram. Substances move from a high concentration to a low concentration; Mitochondria needed; Rate can be increased by stirring; Requires energy; Water moves down a water potential gradient; Protein carriers required; No energy is required; Movement of particles is against a concentration gradient. Active Transport Diffusion Osmosis (4 marks) (Total 7 marks) Page 6 of 16

7 5a. Complete the following by listing the body structures in order of size. The smallest structure is at the top of the list and the largest is at the bottom. i. Cells ii. iii. Organ iv. v. Organism b. The diagram shows one side of an organ donor card. The table below lists different human illnesses. Complete the table by choosing ONE of the donated organs named on the card which is needed to cure each illness. Illness Organ needed to cure illness Diabetes Coronary failure Hepatitis (Total 4 marks) Page 7 of 16

8 6. The organisms shown in the pictures below are a group of invertebrates which belong to different phyla. a. Name the TWO organisms which belong to the same phylum. List the class to which each organism belongs to. b. Describe TWO structural differences between the two organisms which belong to the same phylum. Page 8 of 16

9 c. Which phylum does the snail belong to? Give TWO features which are common to organisms which belong to the same phylum as the snail. d. Cube A is representing a segmented worm while Cube B is representing a cnidarian. (Cubes are not drawn to scale) i) On the above pictures mark the organism representing the segmented worm with an S and the organism representing the cnidarian with a C. ii) Cube A is 7cm x 7cm x 7cm while cube B is 2cm x 2cm x 2cm In the space provided, calculate the surface area to volume ratio of Cube A and Cube B. Cube A:- Page 9 of 16

10 Cube B:- iii. Complete the table by putting one tick in each row to show whether the statement applies to cube A or B. Largest volume. Largest surface area when compared to its volume. Cube A Cube B iv. Which organism needs a special circulatory system - the cnidarian or the segmented worm? Explain your answer in terms of surface area to volume ratio. e. The tapeworm is a parasite. Describe ONE way how this organism is adapted to its parasitic mode of life. (Total 15 marks) Page 10 of 16

11 7a. Use the dichotomous key below to classify the organisms below correctly. i ii) iii) iv) v) vi 1. Feathers.. Ara ararauna No feathers..go to Dry skin... Chamaeleo chamaeleon Moist skin go to Scales go to 5 No scales...go to 4 4. Have Tail as adults. Pleurodeles waltl Have no tail as adults. Anura xenopus 5. Have gill slits. Carcharodon carcharias Have no gill slits and an operculum.thunnus thynnus a. Animal (i). Animal (ii). Animal (iii). Animal (iv). Animal (v). Animal (vi). b. Why are keys useful in classifying organisms? (Total 4 marks) Page 11 of 16

12 SECTION B Answer question ONE and choose any other TWO questions. This section carries 45 marks. Write the answers for section B on a foolscap. The red Crossbill also known as Loxia curvirostra belongs to the finch family. It feeds by using its bill (beak) to force apart the scales on conifer cones. It then uses its tongue to extract the seeds. If the beak is clipped it grows back again. Scientists were interested in the evolution of the bill of the Crossbill. In an investigation, they clipped the bills of several Crossbills so that their bills no longer crossed. They observed that Crossbills with clipped bills took much longer to get seeds. The scientists also noted that the population of the red Cross bill changed between 1976 to In 1977 there was little rain. a. List the species name of the red Crossbill. b. Give TWO advantages of the Binomial system of nomenclature. c. The cross bills are organisms which belong to the class of birds. List TWO ways how birds like crossbills are adapted to fly. d. The Crossbills took a longer time to eat the seeds when their beaks were clipped. What conclusion can you draw from this result? e. The population of the ground finches and their beak sizes changed between 1976 and Describe these changes Page 12 of 16

13 f. Suggest a possible explanation for the changes in beak size between 1976 and g. Are crossbills endothermic or ectothermic organisms? h. Crossbills eat conifer seeds. State if conifer seeds are Angiosperms or Gymnosperms. List ONE difference between Angiosperms and Gymnosperms. i. Conifers have needle-like leaves. Explain j. Describe briefly how conifers carry out reproduction. (Total 15 marks) 2. A company manufactured a new hand-wash. The hand-wash can be diluted with water to make different concentrations. The company asked a scientist to test the effect of different concentrations of hand-wash on bacteria. The scientist started the investigation by first observing the bacteria under the light microscope. a. Draw a labelled diagram of the bacterium that the scientist is likely to have seen. (4 marks) b. After observing the bacterial cell, the scientist concluded that the bacteria is a unicellular Prokaryotic cell. Explain. c. The scientist carried out tests, to check how the bacteria was affected when using different concentrations of hand wash liquid. The scientist s results are shown in the table below:- Percentage Concentration of hand-wash Number of bacteria colonies that grew Test 1 Test 2 Test 3 Mean Describe the results obtained by the scientist. d. Draw a sketch graph of the results shown in the table above. The graph should show how the mean number of colonies of bacteria varies with the concentration of disinfectant. Page 13 of 16

14 e. Name the type of reproduction carried out by bacteria and give ONE advantage of this method of reproduction. f. A hospital worker who saw the results advised that the hospital should use the hand wash liquid at a 75% concentration to make sure most bacteria are killed. Do you agree with this advice? Give ONE reason to explain your answer. g. Bacteria can be beneficial. Discuss this statement. (Total 15 marks) 3. This question is about Protists and Viruses. a. Amoeba is a unicellular organism living either in FRESH or SALT WATER. Which organelle is present in one of them and absent in the other? (1mark) b. Explain how osmoregulation takes place in the Amoeba. Amoeba feeds on smaller organisms by engulfing them, with finger like structures. By using well labelled diagrams describe how amoeba carries out its feeding. c. Euglena can be both Autotrophic and Heterotrophic. Define the terms autotrophic and heterotrophic. d. Euglena has a number of structural features to carry out Autotrophic nutrition. Describe ONE of these features. f. The sentences below show a step by step sequence in viral reproduction. Put them in order, by writing down their sequence properly. i...new viruses pop out of host cell ii...viral Dna migrates to host nucleus and formats host nucleus Dna iii...viral Dna goes into viral coats iv...virus lands on host cell and attaches itself v...viral Dna starts to make many copies of itself using host Dna vi...virus instructs host cell to make many viral coats vii...virus injects viral Dna by using false receptors viii. host cell explodes and dies (4 marks) Page 14 of 16

15 g) A patient has the common flu. He goes to the doctor and expects to get some antibiotics prescribed for him. Does the doctor prescribe antibiotics for this patient? Explain your answer. (Total 15 marks) 4. Give a biological explanation for each of the following statements. a. Leopard seals have adaptations that help them survive in very cold Antarctic region. b. Amphibians and Reptiles both lay eggs but carry out reproduction differently. c. A wilting plant will recover after being watered. d. Humans and Mushrooms feed on ready -made food but carry out digestion differently. e. Being unicellular has a number of advantages. f. A beetle is more susceptible to predators during the moulting process. g. A butterfly changes its shape during its life cycle while the grasshopper changes only in size but keeps the same shape. (Total 15 marks) 5. This question is about Plant classification. a. List ONE similarity and ONE difference between Bryophytes and Pteridophytes. b. Describe the special requirement needed by Bryophytes to carry out reproduction. c. Bryophytes and Pteridophytes grow to different heights. Explain. Page 15 of 16

16 d. A group of biology students went out on a field trip. They had to classify a number of plants, as monocotyledons or dicotyledons. Here are some pictures of specific parts of different plants. In each case state if the picture is representing either a monocot or a dicot plant and give ONE reason to explain you answer. i ii iii iv v (10 marks) (Total 15 marks) Page 16 of 16