0610_w18_qp_41
A paper of Biology, 0610
Questions:
6
Year:
2018
Paper:
4
Variant:
1
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1
shows a pyramid of biomass and part of the carbon cycle. CO2 in atmosphere fossil fuels D C B A decomposers X State the principal source of energy required for trophic level D of the pyramid of biomass in . State the letter that represents the primary consumers in . State how carbon is transferred from producers to primary consumers. Explain why trophic level A is smaller than trophic level B in the pyramid of biomass in . Some fungi and bacteria are decomposers. Define the term decomposer. Arrow X on indicates the transfer of carbon from decomposers to the atmosphere. State the name of process X. Describe how human activities are affecting the carbon cycle.
19. Organisms and their environment  →  19.2. Food chains and food webs
19. Organisms and their environment  →  19.3. Nutrient cycles
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2
Microbiologists test strains of bacteria for antibiotic resistance. They do this by soaking paper discs in antibiotics and placing them on bacteria growing in Petri dishes. The paper discs in the centre of Petri dishes E and F in have been soaked in penicillin. paper disc soaked in penicillin zone where bacteria are growing zone where bacteria are no longer growing E F State the type of microorganism that produces penicillin. State and explain the evidence from that suggests that the bacteria in dish F are resistant to penicillin. Explain how bacteria become resistant to antibiotics and how humans can reduce the problem of antibiotic resistance. Explain why viral infections cannot be treated with antibiotics. Some bacteria and viruses cause disease but many are useful to the biotechnology industry. Explain why bacteria are useful in biotechnology.
15. Drugs  →  15.1. Drugs
21. Biotechnology and genetic modification  →  21.1. Biotechnology and genetic modification
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3
shows a photomicrograph of a section of a root. J K L M Structure J is a xylem vessel. The xylem vessels conduct water from the roots to the stems. State the features of xylem vessels that enable them to conduct water. Describe the pathway of water from outside the root to the xylem vessels (J) at the centre of the root. Use the letters in in your answer. Scientists wanted to determine the flow-rate of water in roots. They measured the flow-rate in three zones of onion roots as shown in . zone 3 zone 2 zone 1 glass jar containing water They measured the flow-rate in healthy roots and roots that had been treated with a toxic solution. Their results are shown in Table 3.1. Table 3.1 zone in average flow-rate of water / arbitrary units healthy roots treated roots Calculate the percentage increase in the average flow-rate between zone 1 and 3 for healthy roots. Give your answer to two significant figures. Show your working. % The scientists observed that the xylem vessels nearer the root tip were narrower than the xylem vessels higher up the root. Describe how the width of xylem vessels in different zones of a root affects the average flow-rate of water. Use the information in Table 3.1 in your answer. Suggest why there was little difference in the flow-rate in healthy roots and in roots treated with the toxic solution.
3. Movement into and out of cells  →  3.2. Osmosis
8. Transport in plants  →  8.2. Water uptake
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4
The eye is a sense organ that responds to light. is a diagram of a section through the human eye. Q W X Y R S T U Table 4.1 describes some of the functions of the parts of the eye. Complete the table by: • naming the parts of the eye • using the letters on to identify the parts of the eye. Table 4.1 function name of part letter on carries impulses to the brain focuses light onto the back of the eye controls the tension of the suspensory ligaments tissue that detects light and colour location of most of the cone cells A pair of muscles in the eye work in opposition to each other to adjust the amount of light entering the pupil. State the term that describes the action of a pair of muscles working in opposition to each other. A different pair of muscles in the eye work in opposition to each other to view objects at different distances from the eye. State the name of the process that allows the eye to view objects at different distances. Explain why the eye cannot easily identify different colours in low levels of light. Some people inherit colour blindness and cannot identify certain colours, even in bright light. The gene responsible for colour vision is located on the X chromosome. There are two alleles for this gene on the X chromosome: • XB – normal colour vision • Xb – colour blindness. People that are heterozygous for colour blindness are called carriers. State the genotype of a heterozygous female carrier. There is no gene for colour vision on the male sex chromosome. State the genotype of a colour-blind male. shows a pedigree diagram for colour blindness. colour vision female carrier female colour-blind female colour vision male carrier male colour-blind male Key: Person 13 in is male. His parents are person 7 and person 8. Use the key to complete by drawing the correct symbol for person 13. Colour blindness is a sex-linked characteristic. Explain why females 4 and 5 are carriers even though their mother is not a carrier.
14. Coordination and response  →  14.2. Sense organs
17. Inheritance  →  17.4. Monohybrid inheritance
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5
The liver is an important organ in many processes. The liver responds to changes in insulin concentration. Insulin is a hormone. Define the term hormone. Describe how the liver responds to an increase in insulin concentration. The liver is also involved in the processing of amino acids. Describe how excess amino acids are broken down. State the name of the process that assembles amino acids to form proteins. The liver is also involved in the processing of toxins. Lactic acid is an example of a toxin that is produced during vigorous exercise and processed in the liver. Describe how lactic acid is processed. Alcohol is another toxin that is processed in the liver. The effect of alcohol consumption on the risk of dying from liver disease was investigated in men and women. The results are shown in . men women alcohol consumption / g per day risk of dying from liver disease / arbitrary units Key: Describe the results shown in .
13. Excretion in humans  →  13.1. Excretion in humans
14. Coordination and response  →  14.4. Homeostasis
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6
Young mammals that are orphaned can be bottle-fed. shows a newborn tiger cub sucking on a bottle. Sucking is an example of an involuntary action observed in newborn mammals. State the name given to involuntary actions. Describe the advantages of breast-feeding compared with bottle-feeding. The digestive systems of young mammals are not fully developed. Enzymes such as amylase, maltase and protease are often added to baby food to aid chemical digestion. Complete Table 6.1 by stating the substrate and productfor each enzyme reaction. Table 6.1 enzyme substrate productamylase maltase protease Suggest why the temperature of baby food must be controlled when the enzymes are added. State one other condition that must also be controlled to optimise enzyme activity.
5. Enzymes  →  5.1. Enzymes
10. Diseases and immunity  →  10.1. Diseases and immunity
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