0610_s20_qp_41
A paper of Biology, 0610
Questions:
6
Year:
2020
Paper:
4
Variant:
1
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1
The gas exchange system is one of the organ systems of the human body. shows parts of the gas exchange system during breathing in and breathing out. breathing in breathing out intercostal muscles sternum diaphragm vertebrae Complete Table 1.1 to show: • the functions of the diaphragm and the intercostal muscles during breathing in and breathing out • the pressure changes in the thorax. Use these words: contract relax increases decreases. Table 1.1 diaphragm intercostal muscles pressure change in the thorax internal external breathing in breathing out shows part of the gas exchange surface of a human. movement of air magnification ×350 X State two features of the gas exchange surface that are visible in . The cells labelled X on form a tissue. Define the term tissue. Cartilage is another tissue found in the gas exchange system. State the functions of cartilage in the gas exchange system.
11. Gas exchange in humans  →  11.1. Gas exchange in humans
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2
Biological washing powders contain enzymes that break down food stains. Complete Table 2.1 by naming the enzymes that break down three substances in food stains and by stating the product or products. Table 2.1 substance enzyme productstarch fat protein Some students compared how effective biological and non-biological washing powders are at removing stains at temperatures between 10 °C and 60 °C. • Pieces of stained cloth were washed using two different washing powders. • The degree of stain removal was measured by using a light meter to record the percentage of light reflected from the cloth. • A light meter gave a value of 100% when the cloth was completely clean. • Any stain left on the cloth reduced the percentage of light reflected. The results of the students’ investigation are shown in . percentage of light reflected after washing temperature of washing / °C Key: non-biological washing powder biological washing powder Compare the effectiveness of the two washing powders at removing stains. Use the information in in your answer. The students suggested that the enzymes in the biological washing powder were denatured at high temperatures. Explain why enzyme molecules do not function when they are denatured. Forensic scientists often try to find DNA on items of stained clothing. The DNA can be used to identify individual people. Suggest why DNA can be used to identify individual people.
21. Biotechnology and genetic modification  →  21.2. Biotechnology
5. Enzymes  →  5.1. Enzymes
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3
Dialysis tubing is an artificial membrane, which is similar to the lining of the intestine. A student investigated the diffusion of glucose through dialysis tubing by using the apparatus shown in . rubber band to secure the dialysis tubing water outside the dialysis tubing knot at the end of the dialysis tubing glucose solution dialysis tubing The student took samples of the water outside the dialysis tubing at 5 minute intervals and tested the samples with Benedict’s solution. The results are shown in Table 3.1. Table 3.1 time / minutes results of the Benedict’s tests on the water outside the dialysis tubing blue green yellow red Describe and explain the results shown in Table 3.1. The student repeated the investigation with a higher concentration of glucose in the dialysis tubing. Predict the results that the student would observe. shows a drawing of a cell from the lining of the small intestine. The lumen is the space inside the intestine where food is digested. A C B not to scale lumen of the intestine State the names of the three labelled structures in and describe the role of each structure in the intestinal cell. The cholera bacterium can survive in the small intestine and the large intestine. The bacterium releases a toxin that interacts with receptors on the surface of cells. shows the effect of the toxin. The arrows indicate the direction of movement. Key: toxin ion X bacterium not to scale lumen of the intestine The toxin stimulates the secretion of ion X out of the intestinal cell. State the name of ion X. Describe the effects on the body of the secretion of ion X into the lumen of the intestine.
10. Diseases and immunity  →  10.1. Diseases and immunity
13. Excretion in humans  →  13.1. Excretion in humans
3. Movement into and out of cells  →  3.2. Osmosis
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4
Johnson grass, Sorghum halepense, is wind-pollinated. shows some Johnson grass flowers. State the genus of Johnson grass. Describe two features visible in that show that Johnson grass flowers are adapted for wind-pollination. shows a section through a carpel shortly after pollination. D A C B E State the names of the parts of the carpel labelled C, D and E. C D E Complete the sentences: Pollen grains are formed in anthers. During their formation the number of chromosomes in the nuclei is halved by the process of . This means the male nucleus A in the pollen tube is described as a nucleus. When nucleus A with nucleus B, the chromosome number doubles to form a nucleus. The name of this process is . Then the divides by the process of to form an embryo. Discuss the advantages of sexual reproduction to a wild population of flowering plants such as Johnson grass. Sexual reproduction requires energy. State three uses of energy in organisms other than in reproduction.
16. Reproduction  →  16.3. Sexual reproduction in plants
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5
Ciliates are classified in the kingdom Protoctist. Bacteria are classified in the kingdom Prokaryote. State two structural features that distinguish the cells of a protoctist from a prokaryote. shows five species of ciliate that are found in sewage treatment works. A Chilodonella C Euplotes D Paramecium E Vorticella not to scale B Didinium rows of cilia cilia cilia fused together Didinium is a predatory ciliate. A video recording was made of one Didinium feeding on a Paramecium. shows a sequence of still photographs taken from the video. Paramecium Didinium Complete the table by putting a tick (✓) by each characteristic of life that can be seen in the still photographs from the video in . excretion nutrition growth reproduction movement respiration is a food web for some of the microorganisms in a sewage treatment works. Didinium Paramecium Vorticella rotifers photosynthetic bacteria decomposer bacteria nematodes Construct one food chain with three trophic levels that use energy derived from the breakdown of sewage. Do not draw the organisms. The water that passed out of the sewage works was often cloudy with suspended matter. Scientists discovered that ciliates reduce the cloudiness of water during sewage treatment. Suggest how the ciliates reduce the cloudiness of the water using the information in . Explain how sewage treatment reduces the spread of disease. Nitrifying bacteria are found in sewage works. Explain the importance of nitrifying bacteria in the nitrogen cycle.
10. Diseases and immunity  →  10.1. Diseases and immunity
19. Organisms and their environment  →  19.3. Nutrient cycles
20. Human influences on ecosystems  →  20.3. Pollution
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6
Colour blindness is a characteristic that is inherited. Colour blindness is more common in males than in females. is a pedigree diagram showing the inheritance of colour blindness in a family. male with normal colour vision male with colour blindness female with normal colour vision Key: Define the term inheritance. Using the symbols B and b, state the genotypes of individual 5 and individual 8 in the pedigree diagram. Individual 3 is a carrier of colour blindness because she has one copy of the allele for colour blindness but has normal colour vision. Describe the evidence from that shows that individual 3 is a carrier. There was no history of colour blindness in the parents and grandparents of individuals 1 and 2. Suggest how colour blindness first occurred in the family in .
17. Inheritance  →  17.4. Monohybrid inheritance
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