A unicellular animal P having no fixed shape ingests a food particle by forming temporary finger-like projections Q. The food particle is engulfed with a little surrounding water to form a temporary stomach R inside it. The chemicals S from surrounding cytoplasm enter into R and break down food into small and soluble molecules by chemical reactions. The digested food is absorbed directly into cytoplasm by the process T. The undigested food is thrown out of the body by the rupture of a cell organelle U in a process called V.

(a) Name the unicellular animal P. (b) What are (i) Q and (ii) R ?

(c) Name (i) chemicalS, and (ii) process T.

(d) Name (i) organelle U, and (ii) process V.

When a person puts food in his mouth, then teeth cut it into small pieces, chew and grind it. The glands A in the mouth secrete a substance B which is mixed with the food by tongue. The substance B contains an enzyme C which starts the digestion of food in the mouth. The slightly digested food from the mouth goes down a tube D. The special type of movements E in the walls of tube D push the food into stomach for further digestion. The stomach wall secretes gastric juice containing three substance F, G and H. One of the functions of F is to kill bacteria which may enter the stomach with food. The substance G protects the inside layer of stomach from the damaging effect of substance F whereas substance H is an enzyme for digestion. The partially digested food then enters into small intestine for further digestion.

(a) What is (i) gland A

(ii) substance B, and (iii) enzyme C?

(b) Name the tube D.

(c) What is the movement E known as?

(d) What are (i) F (ii) G, and (iii) H?

The partially digested food coming from the stomach of a person enters a long and narrow organ A in his body. The organ A receives the secretions of two glands : liver and pancreas. Liver secretes a greenish yellow liquid B which is normally stored in the organ C. Pancreas secretes pancreatic juice which contains three digestive enzymes D, E and F. The intestinal juice completes the process of digestion of food. The inner wall of organ A has millions of tiny finger-like projections G which help in the rapid absorption of digested food into blood stream. The undigested part of food then passes into wider tube H which absorbs most of the water from undigested food. The last part of tube H called I stores this undigested food (or waste) for some time. The undigested food is then passed out though opening J as faeces in the process known as K.

(a) Name the organ A

(b) Name (t) liquid B, and (it) organ C.

(c) What are the digestive enzymes D, E and F?

(d) Name the projections G present on the inner wall of organ A.

(e) Name (i) tube H (ii) part I (iii) opening J, and (iv) process K.

There are four organisms A, B, C and D. The organism A eats only the flesh of other animals as food. The organism B can eat grains, fruits and vegetables as well as meat and fish. The organism C can make the food itself from simple inorganic substances present in the environment by utilising sunlight energy. On the other hand, organism D eats only plants and their products as food.

(a) Which organism is (i) omnivore

(ii) herbivore, and (iii) carnivore ?

(b) Which organism is an autotroph ?

(c) Which organism is/are heterotroph(s)?

(d) Which organism can be a producer ?

(e) Which organism is/are consumer (s)?

(f) Give one example each of organisms which could be like (i) A (ii) B (iii) C, and (iv) D

The organisms A, B and C can obtain their food in three different ways. Organism A derives its food from the body of another living organism which is called its D, without killing it. The organism B takes in the solid food by the process of ingestion, digests a part of this food and throws out undigested food in the process called E. The organism C obtains its food from dead and decaying plants.

(a) What is the mode of nutrition of

(i) organism A

(ii) organism B, and

(iii) organism C ?

(b) What is the organism like D called ?

(c) Name the process E.

(d) Give one example each of organisms like (i) A (ii) B, and (ii) C.

(e) What is the general name of three modes of nutrition exhibited by organisms A, B and C ?