5090_w23_qp_21
A paper of Biology, 5090
Questions:
8
Year:
2023
Paper:
2
Variant:
1
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1
Human blood has many different components and functions. Match each component to its function by drawing a line between them. One has been done for you. component of blood function red blood cell platelet plasma phagocyte lymphocyte engulfs pathogens transports oxygen makes antibodies transports fibrinogen involved in clotting Explain how a red blood cell is specialised for transporting oxygen. The number of red blood cells in 1 mm3 of blood is called a red blood cell count. A normal red blood cell count for a female is 4.2 – 5.4 million cells in 1 mm3 of blood. Suggest two factors that could lead to a change in the red blood cell count in a 25 year‑old female.
11. Transport in humans  →  11.4. Blood
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2
shows the life cycle of the plant Coffea arabica. This plant produces seeds which are used to make coffee. A a flower D a young seedling B process C two seeds growth pollination and development dispersal (not to scale) Complete by labelling the plant structure B and the process taking place between C and D. The flowers produce nectar in nectaries and are pollinated by insects, such as bees. Suggest where the nectaries are located and how this assists the process of pollination. After pollination, pollen tubes grow down the style. Describe what then happens leading to the formation of B and its contents. Coffea arabica plants produce a chemical called caffeine which in high concentrations is toxic to insects. Suggest why the production of caffeine is useful to the plant. Caffeine is found throughout the plant but in some parts the concentration is much higher than in others. Suggest why it is important to the plant to have different concentrations in different parts. Coffee is a drink that many humans enjoy. The caffeine in the coffee causes the body to release adrenaline. Using caffeine and adrenaline as examples, explain the difference between a drug and a hormone. Suggest two effects on the body of drinking coffee that contains caffeine.
16. Development of organisms and continuity of life  →  16.3. Sexual reproduction in plants
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3
The bar chart in shows the percentage of total human body mass for the five most common elements found in the human body. percentage of total human body mass oxygen carbon hydrogen elements nitrogen calcium Calculate the percentage of the total human body mass made up from the three most common elements. total = % Name two types of substance found in the human body that contain only carbon, hydrogen and oxygen. Water contains the elements hydrogen and oxygen and makes up a large percentage of an adult’s total body mass. Discuss why water makes up such a high percentage of an adult’s total body mass. Explain why a cell from human tissue will burst when it is placed in water. Human tissues contain different percentage masses of the elements shown in . Suggest one tissue that contains a relatively high percentage mass of nitrogen and explain your answer.
9. Human gas exchange  →  9.1. Human gas exchange
4. Biological molecules  →  4.1. Biological molecules
8. Human nutrition  →  8.1. Diet
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4
A sneeze can be triggered by dust irritating receptor cells in the lining of the nose or throat. During a sneeze, air is exhaled from the lungs with some force and the eyelids close. air exhaled from nose and mouth Suggest how the closure of the eyelids during a sneeze is coordinated. Suggest how sneezing can result in disease transmission. A sudden increase in light intensity can trigger sneezing in some people. This is called photic sneezing. It is estimated that 18 – 35% of the human population can be triggered to sneeze by an increase in light intensity. The genetic basis for photic sneezing is not fully understood but it is thought that a dominant allele is involved. Give the name of this type of variation in a population and explain your answer. type of variation explanation Describe what is meant by the term dominant allele.
17. Inheritance  →  17.4. Selection
17. Inheritance  →  17.3. Inheritance
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5
shows two structures found in the human digestive system. a tooth a salivary gland (not to scale) Identify the type of tooth shown in the diagram. Name the outer layer of the tooth. Explain how the tooth and the salivary gland contribute to digestion in different ways. The stomach wall produces different substances that are involved in digestion. Name two of these substances and explain how they are involved in digestion. A hormone called gastrin stimulates cells in the stomach wall to release the substances involved in digestion. Some of the gastrin is produced in the duodenum. State how this gastrin reaches the stomach.
8. Human nutrition  →  8.2. Human digestive system
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7
A root hair cell in a plant is respiring aerobically. Name the structures within the cell that carry out aerobic respiration. Write the balanced symbol equation for the aerobic respiration of glucose, C6H12O6. The plant experiences changing weather conditions including: high temperature heavy rain high winds low humidity State the weather condition that may lead to a root hair cell respiring anaerobically and explain your answer. weather condition explanation
7. Transport in flowering plants  →  7.1. Uptake and transport of water and ions
10. Respiration  →  10.2. Aerobic respiration
1. Cells  →  1.1. Cell structure and function
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8
The number of individuals in a population can vary with time. Table 8.1 shows how the global populations of humans and tigers are estimated to have changed between 1970 and 2000. Table 8.1 year estimated global population humans tigers 3.6 billion 35 000 6.0 billion 5 000 Suggest factors that may be causing these changes in the two populations and how the changes may be linked. In 2010 the population of tigers had dropped to an estimated 3200. Thirteen countries in which tigers live signed an agreement to double their tiger populations by 2022. Explain why it is important to increase tiger populations and suggest ways of doing this.
19. Relationships of organisms with one another and with the environment  →  19.3. Ecosystems and biodiversity
19. Relationships of organisms with one another and with the environment  →  19.5. Conservation
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