Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
What criteria do we use to decide whether something is alive?
What are outside raw materials used by an organism?
What processes would you consider essential for maintaining life?
What are the difference between autotrophic and heterotrophic nutrition?
Where do plants get each of the raw materials required for photosynthesis?
What is the role of acid in our stomach?
What is the function of digestive enzymes?
How is small intestine designed to absorb digested food?
The autotrophic mode of nutrition requires
1. carbon dioxide and water
4. All of the above
How are fats digested in our bodies? Where does this process take place?
What is the role of saliva in the digestion of food?
What are the necessary conditions for autotrophic nutrition and what are its byproducts?
Energy is required by an organism even during sleep. Why?
Chemosynthetic mode of nutrition is different from photosynthetic mode in which way?
Some organisms derive nutrition from plants or animals without killing them. What are these organisms called? Write one example.
Name the different types of teeth in humans.
Name the glands present in the wall of the stomach that release secretions for digestion of food. Write three components of secretion that are released by these glands.
What do you mean by emulsification of fat?
Name the enzyme produced by the cells of our stomach in small amount in order to digest butter fat in our food.
What are the final products obtained after the digestion of carbohydrates and proteins?
In human alimentary canal, name the site of complete digestion of various components of food.
Mention the site of complete digestion of carbohydrates, proteins and fats in humans.
Name the enzyme, which initiates the protein digestion.
In an activity by a group of student, the proportions of chemical constituents of the human body is drawn on the graph.
Name the major and least constituents of the body reference to the graph.
In an experiment, saliva is added to the test tube containing pieces of bread (powdered). What will be the result?
What is the primary requirement for pancreatic enzymes to act?
Digestive enzymes are also called as hydrolases. Why?
Lipase solution was added to milk. After 30 minutes, the milk had become more acidic. What was the substrate and end products in this reaction?
In a particular experiment, milk produces red precipitate when heated with the Benedict's solution. According to you which nutrients are present in the milk?
How do the guards cells regulate the process of opening and closing of stomatal pores?
Name the components which you will observe when you focus the stomata slide under high power objective of a microscope.
What is photolysis and when does it occur?
Name any two parasitic plants and two parasitic animals.
Match the following columns.
Digestion in food vacuoles
Draw a labelled diagram of cross-section of a leaf.
(i) Which part of the alimentary canal helps in eliminating the unabsorbed food?
(ii) How is the exit of waste material regulated?
Which is the largest digestive gland in human body? What is its function?
How would digestion of food be affected if the bile duct is completely blocked?
The diagram shows the inside of the small intestine. Using the structure shown, explain how structure of the lining of the small intestine help to absorb more food.
How is the required pH maintained in the stomach and small intestine?
How is egestion different from ingestion?
Why does our mouth water when we eat something?
Why does a piece of bread start tasting sweeter after it is chewed for some time?
Why is small intestine in herbivores longer than in carnivores?
Two green plants are kept separately in oxygen free containers, one in the dark and other in the continuous light. Which one will live longer? Give reasons.
Plaque is a deposit, which collects around teeth. The following table shows the pH value of the plaque surrounding the teeth of a girl over 4 hrs.
(i) Other than food remains, state three constituents of plaque.
(ii) State the time during the day, when conditions are most favorable for the process of tooth decay.
Food does not pass through the digestive system by 'gravity'. This is clear from the fact that we can digest the food even if we are lying down. Explain the logic behind the passage of food through our digestive system.
Name the following.
(i) The process in plants that links light energy with chemical energy.
(ii) Organisms that can prepare their own food.
(iii) The cell organelle where photosynthesis occurs.
(iv) Cells that surround a stomatal pore.
(v) Organisms that cannot prepare their own food.
(vi) An enzyme secreted from gastric glands in stomach that acts on proteins.
What are the adaptations of leaf for photosynthesis?
List the three events that occur during the process of photosynthesis. Explain the role of stomata in this process.
In each of the following situations what happens to the rate of photosynthesis?
(i) Cloudy days
(ii) No rainfall in the area
(iii) Good manuring in the area
Write a short note on different types of heterotrophic nutrition.
Explain with the help of neat and well-labelled diagrams the different steps involved in the nutrition in Amoeba.
Give one word for the following:
(i) I am secreted from the walls of stomach.
I kill all the harmful germs present in food and help my friend pepsin to work in aidic medium.
(ii) We are the biocatalysts. We enhance the rate of metabolic activities.
(iii) We push the food forward by a rhythmic contraction.
State the function of the following in the alimentary canal:
(i) Liver (ii) Gall bladder (iii) Villi
Name the correct substance for the following enzymes.
(a) Trypsin (b) Amylase
(c) Pepsin (d) Lipase
(i) Why is nutrition a necessity for an organism? State three reasons.
(ii) What is likely to happen if green plants disappear from Earth?
Describe the holozoic nutrition in details using one example.
Explain the process of digestion of food in mouth, stomach and small intestine in human body.
(i) Draw a diagram depicting human alimentary canal and label the components gall bladder, liver and pancreas in it.
(ii) State the role of liver and pancreas.
(iii) Name the organs which perform the following functions in humans.
(a) Absorption of digested food
(b) Absorption of water
(i) Mention the role of HCl in the stomach.
(ii) What function is served by the following?
(a) Gastric sphincter
(b) Anal sphincter
The graph shows how the amount of carbon dioxide taken in by a plant varies through a 24 hour period.
(i) At what time did photosynthesis start?
(ii) At what time was the rate of photosynthesis greatest?
(iii) At what time of the day did it get dark?
(iv) (a) How does plant obtain CO2?
(b) What happens to this CO2?
(v) What other factors could affect the rate of photosynthesis?
Figure A shows the human alimentary canal.
(i) In fig. A, label structures T, U and V
(ii) Name the secretion, which passes down tube W and explain how it helps in fat digestion.
(iii) In case of diarrhoea, name the major process in region X, which is no longer occurring normally.
A student prepared the temporary mount of stained leaf peel. After observing the slide under microscope, he drew the following sketch. Correct the parts A, B, C and D labelled by him.
A student could not clearly observe the stomata from mount of leaf peel. Give reason for this happening.
In an experiment to prepare temporary stained mount of a leaf epidermal peel, how can extra stain be removed? What possible outcome would be observed if it is removed with cotton wool?
Explain, why only turgid leaf is selected for the preparation of temporary mount of a leaf peel?
Geetika after coming home told her mother that she wants to plant some trees as she needs to know and observe how plants grow by preparing their own food and transfer it to other organs. She placed two potted plants in her room and observed after 3-4 weeks that leaves had become pale-yellow in colour instead of green in colour. She realised her error and placed the plants in sunlight.
Read the passage given below and answer the questions that follow:
(i) What is photosynthesis? Also mention the conditions necessary for photosynthesis.
(ii) What according to you was the condition missing in the given case that leads to that improper growth of plant?
(iii) What values are observed in Geetika's action?
Smriddhi's father has a plot of land in the city where he wants to construct a house. The area has few trees, which are very dear to her father and he does not want to cut the trees, as trees provide us oxygen which is very essential for living organisms. Her father also desperately needs a house for his family.
Read the given passage and answer the following questions:
(i) Should Smriddhi's father construct the house after cutting the trees?
(ii) How can the family compensate for the loss in terms of oxygen supply?
(iii) What practices will be required after planting the trees?
(iv) What values are shown by Smriddhi's father?
Neeraj, class IX student is extremely fond of chocolates and junk food. He often complains of pain in his teeth and misses school many times. Due to which, he is lacking in his studies too. Teacher called up his father and asked him to take Neeraj to the dentist. The dentist, after examining suggested that Neeraj is suffering from tooth decay and advised him to quit eating unhealthy and outside food.
On the basis of above text, answer the following questions.
(i) What do you know about the term tooth decay?
(ii) How does tooth decay occur? Suggest any one treatment for it.
(iii) What values should Neeraj incorporate in himself for good health of his teeth?