Life Processes quiz

The kidneys in human beings are a part of the system for:

The xylem in plants is responsible for:

The autotrophic mode of nutrition requires:

The breakdown of pyruvate to give carbon dioxide, water and energy takes place in the:

Pepsin, a protein-digesting enzyme, acts in the:

Which blood vessel carries oxygenated blood from the lungs to the heart?

Anaerobic respiration in yeast produces:

The opening and closing of stomata is controlled by:

The normal blood pressure of a healthy adult is about:

Lymph carries digested and absorbed:

How is the amount of urine produced regulated? (2 marks)

What are the functions of hydrochloric acid in the stomach? (2 marks)

How are the lungs designed in human beings to maximise the area for the exchange of gases? (2 marks)

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds? (2 marks)

What are the components of the transport system in highly organised plants? (2 marks)

How do guard cells regulate the opening and closing of stomatal pores? (2 marks)

What is the role of saliva in the digestion of food? (2 marks)

What would be the consequences of a deficiency of haemoglobin in our bodies? (2 marks)

Why do fishes have a two-chambered heart while mammals have a four-chambered heart? (2 marks)

How do plants get rid of their excretory products? (2 marks)

A leaf disc experiment shows that a destarched variegated leaf, after exposure to sunlight, stains blue-black with iodine only in its green parts. If 40% of the leaf area is white and the total leaf area is 50 cm^2, what area would stain blue-black? Explain what the experiment proves. (3 marks)

A person's blood pressure is measured as 150/95 mm of Hg. The normal value is 120/80 mm of Hg. Calculate the percentage by which the systolic pressure exceeds the normal value. Name the condition and the instrument used to measure blood pressure. (3 marks)

The total surface area of the alveoli in human lungs is about 80 m^2. If a tennis court has an area of about 260 m^2, what fraction of a tennis court is this? Explain why such a large area is necessary. (3 marks)

An adult has about 5 litres of blood. If the heart pumps 5 litres per minute, how many times does the entire blood volume pass through the heart in one hour? Express the time for one complete circulation in seconds. (3 marks)

A potted plant was weighed at 8 a.m. (2.400 kg) and at 4 p.m. (2.250 kg) on a sunny day, with the soil surface covered so that water could not evaporate from it. Calculate the water lost per hour. Name the process and state two of its functions. (3 marks)

Read the passage and answer the questions. Ravi conducted an experiment by covering a potted plant with a bell jar along with a watch glass containing potassium hydroxide (KOH) pellets. A similar plant was kept under another bell jar without KOH. Both were kept in the dark for 3 days and then in sunlight for a few hours. A leaf from each plant was tested with iodine solution. (i) What is the role of potassium hydroxide in the experiment? (ii) Which leaf will turn blue-black? Why? (iii) Why were the plants kept in the dark before the experiment? (5 marks)

Read the passage and answer the questions. Meera's grandfather suffers from kidney failure and visits a hospital twice a week for dialysis. The doctor explained that the artificial kidney removes nitrogenous wastes from the blood through a semi-permeable membrane in a tank of dialysing fluid. (i) Name the main nitrogenous waste removed from the blood. (ii) How is dialysis similar to the working of the nephron? (iii) How is it different from a normal kidney in terms of reabsorption? (5 marks)

Read the passage and answer the questions. During a school sports day, Arjun ran a 400 m race. After the race, his heart rate and breathing rate were both very high and his leg muscles hurt. (i) Why did his heart rate and breathing rate increase? (ii) What substance accumulated in his muscles and why? (iii) Write the pathway of glucose breakdown in his muscle cells when oxygen was insufficient. (5 marks)

Read the passage and answer the questions. A student studied the human digestive system and listed the enzymes: salivary amylase, pepsin, trypsin, lipase and the enzymes of intestinal juice. (i) Name the substances digested by salivary amylase and lipase. (ii) Which juice contains trypsin, and what does it digest? (iii) What are the final products of digestion of carbohydrates, proteins and fats? (5 marks)

Read the passage and answer the questions. Blood is a fluid connective tissue made up of plasma, red blood cells, white blood cells and platelets. When we get a cut, the bleeding stops after some time due to clotting. Some people have a disorder in which blood does not clot properly. (i) Name the blood cells that help in clotting. (ii) What is the function of haemoglobin in red blood cells? (iii) Why is a loss of blood pressure dangerous during excessive bleeding? (5 marks)

Describe the process of photosynthesis with a balanced equation. Draw a labelled diagram of an open and a closed stomatal pore, showing the guard cells and chloroplasts. Describe an experiment to show that chlorophyll is necessary for photosynthesis. (6 marks)

Describe the process of digestion of food in the human alimentary canal from the mouth to the small intestine, naming the enzymes and their action at each stage. Draw a labelled diagram of a villus and explain its role in absorption. (6 marks)

Explain the breakdown of glucose by various pathways with a flow chart showing aerobic respiration in mitochondria, anaerobic respiration in yeast, and the formation of lactic acid in muscles. Draw a labelled diagram of the human respiratory system. (6 marks)

Describe the structure of the human heart with a labelled diagram, and trace the path of blood through the heart, lungs and body in double circulation. Distinguish between arteries, veins and capillaries. (6 marks)

Describe the structure and functioning of the human excretory system with a labelled diagram of the kidneys, ureters, urinary bladder and urethra. Explain how urine is formed in a nephron. What is haemodialysis and when is it needed? (6 marks)