Explore NCERT Solutions

Exercise (NCERT Text Book) Chapter -1  

---

Q1. – Why do organisms need to take food?

Ans – Organisms need food to

(i) Get energy to do work.

(ii) Build up body .

(iii) Repair damages in the body.

(iv) Maintain the functions of the body.

Q2. – Distinguish between a parasite and a saprotroph.

Ans. – Parasite: 

(i) It gets nutrients from host on which they live.

(ii) It lives on or in the host.

(iii) Ex: Cuscuta 

Saprotroph : -

(i) It gets nutrient from dead and decaying matter.

(ii) It lives on dead or decaying stuff.

(iii) Ex: Bacteria and fungi. 

Q3. – How would you test the presence of starch in leaves?

Ans : When iodine comes in contact with starch, a dark blue colour appears.  Testing the presence of starch in leaves, when we dropped some solution of iodine on leaves they give dark blue colour. Thus we can say there is starch in leaves.  

Q4. – Give a brief description of the process of synthesis of food in green plants.

Ans : the process of synthesis of food in green plants is called photosynthesis, in which green palnts synthesise their food using carbon dioxide and water in presence of chlorophyll and sunlight. This process takes place in leaves.  The products of photosynthesis are carbohydrate and oxygen. The equation of this process is

Q5.  – Show with the help of a sketch that the plants are the ultimate source of food.

Ans :

Q6.  – Fill in the blanks:

(a) Green plants are called _________________ since they synthesise their own food.

(b) The food synthesised by the plants is stored as _________________.

(c) In photosynthesis solar energy is captured by the pigment called ___________.

(d) During photosynthesis plants take in ______________________ and release __________________.

Ans:

(a)         Autotrophs

(b)         Starch

(c)          Chlorophyll

(d)         carbon dioxide and water, carbohydrate and oxygen.

Q7.  – Name the following:

(i) A parasitic plant with yellow, slender and tubular stem.

Ans : cuscuta (Amarbel)

(ii) A plant that has both autotrophic and heterotrophic mode of nutrition.

Ans : Pitcher plant

(iii) The pores through which leaves exchange gases.

Ans : Stomata

Q8.  – Tick the correct answer:

(a) Amarbel is an example of:

(i) autotroph                   

(ii) parasite                     

(iii) saprotroph                             

(iv) host

Ans : (ii) Parasite

(b) The plant which traps and feeds on insects is:

(i) cuscuta                        

(ii) china rose                 

(iv) pitcher plant                          

(iv) rose

Ans : (iv) pitcher plant

Q9.  – Match the items given in Column I with those in Column II:

Column I                            Column II

Chlorophyll                         Bacteria

Nitrogen                           Heterotrophs

Amarbel                           Pitcher plant

Animals                            Leaf

Insects                             Parasite

Ans :

Column I                            Column II

Chlorophyll                           Leaf

Nitrogen                             Bacteria

Amarbel                              Parasite

Animals                              Heterotrophs

Insects                               pitcher plant

 

Q10. – Mark ‘T’ if the statement is true and ‘F’ if it is false:

(i)  Carbon dioxide is released during photosynthesis. (T/F)

(ii)  Plants which synthesise their food themselves are called saprotrophs. (T/F)

(iii) The product of photosynthesis is not a protein. (T/F)

(iv) Solar energy is converted into chemical energy during photosynthesis. (T/F)

Ans :

(i)  F

(ii)  F

(iii) T

(iv) T

Q11. – Choose the correct option from the following:

Which part of the plant gets carbon dioxide from the air for photosynthesis.

(i) root hair (ii) stomata (iii) leaf veins (iv) sepals

Ans : (ii) stomata

Q12. – Choose the correct option from the following:

Plants take carbon dioxide from the atmosphere mainly through their:

(i) roots (ii) stem (iii) flowers (iv) leaves

Ans : (iv) leaves

Nutrition in Plants   

---

Ques1:- What is the stomata?

Ans:- There are tiny pores present on the surface of the leaves. These pores are surrounded by guard cells. Such pores are called stomata.

Ques2:- Write the function of stomata.

Ans:- The function of stomata

(i) Transportation of gases occurs through the stomata.

(ii) Vaporisation also takes place through it.

Ques3:- Why are algae green in colour? 

Ans:- Due to chlorophyll

Ques4:- What is parasite? 

Ans:- The organism that derives nutrients from another organism without benefiting, it is called parasite. 

Ques5:- What are algae? 

Ans:- Slimy, green patches in ponds or in other stagnant water bodies are observed. These are generally formed by the growth of organisms called algae. 

Ques6:- What is host?

Ans:- Some organisms allow another to live and get nutrient to itself. These organisms are called host. 

Ques7:- Write the type of heterotrophic mode of nutrition.

Ans:-

(i) Parasitic mode of nutrition.

(ii) Saprotrophic mode of nutrition.

Ques8:- Name a plant which takes nutrients as parasitic mode of nutrition.

Ans:- Cuscuta.

Ques9:- Name a insectivorous plant.

Ans:- Pitcher plant.

Ques10:- Name some organisms that intake Saprotrophic mode of nutrition.

Ans:- Bacteria, Fungi and algae etc.

Ques11:- What is symbiotic relationship?

Ans:- Some organisms live together and share shelter and nutrients. This is called symbiotic relationship.

Ques12:- Name the bacteria which convert nitrogen in its soluble form.

Ans:- Rhizobium. 

Ques13:- Name a organism which make a symbiotic relationship. 

Ans:- Lichens. 

Ques14:- Name the bacteria which are found in the roots of gram, peas and other legumes plants. 

Ans:- Rhizobium.

Ques15:- What are cells?

Ans:- The bodies of living organisms are made of tiny units called cells.

Ques16:- What is cell membrane?

Ans:- The cell is enclosed by a thin outer boundary, called the cell membrane.

Ques17:- What is nucleus? 

Ans:- Most cells have a distinct, centrally located spherical structure called the nucleus.

Ques18:- What is cytoplasm?

Ans:- The nucleus is surrounded by a jelly-like substance called cytoplasm.

Ques19:- What is chlorophyll?
Ans:- It is a green pigment found in plants which helps is photosynthesis. 

1. Nutrition in Plants

---

Ques1:- Give a brief description of the process of synthesis of food in green plants.

Ans:- The process of synthesis of food in green plants is known as photosynthesis. In which green plants take CO2 and water as a raw material. This process occurs in presence of chlorophyll which is a green pigment. Plants store synthesised food in leaves. 

Ques2:- What are insectivorous plants?

Ans:- The insect is digested by the digestive juices secreted in the pitcher. Such insect-eating plants are called insectivorous plants.

Ques3:- From where do the plants obtain nitrogen?
Ans:- Soil has certain bacteria that convert gaseous nitrogen into a usable form and release it into the soil. These soluble forms are absorbed by the plants along with water.

Ques4:- What is so special about the leaves that they can synthesis food but other parts of the plant cannot?
Ans:- Because the leaves have a green pigment called chlorophyll.

Ques5:- What is photosynthesis?
Ans:- The process by which green plants make their food from water and carbon dioxide in presence pf sunlight is called photosynthesis.

Ques6:- What is Saprotrophic mode of nutrition?

Ans:- The mode of nutrition in which the organisms take in nutrients in solution form from dead and decaying matter is called Saprotrophic mode of nutrition.

Ques7:- What is autotrophs?
Ans:- Organisms that can make their own food are called autotrophs or producers. 
For ex. Green plants. 

Ques8:- How would you test the presence of starch in leaves?

Ans:- When iodine comes in contact with starch, a dark blue colour appears. Testing the presence of starch in leaves, when we dropped some solution of iodine on leaves they give dark blue colour. Thus we can say there is starch in leaves. 

Ques9:- Write the differences between a parasite and a saprotroph.

Ans:- 

Parasite :- 

(i) It gets nutrients from host on which they live.

(ii) It lives on or in the host.

(iii) Ex: Cuscuta 

Saprotroph :-

(i) It gets nutrient from dead and decaying matter.

(ii) It lives on dead or decaying stuff.

(iii) Ex: Bacteria and fungi.

Ques10:- Why do organisms take food?

Ans:- Organisms need food to

(i) Get energy to do work.

(ii) Build up body .

(iii) Repair damages in the body.

(iv) Maintain the functions of the body.