What is the significance of emulsification of fats?
Fats are present in food in the form of large globules which makes it difficult for enzymes to act on them. Bile salts present in bile break them down mechanically into smaller globules which increases the efficiency of fat digesting enzymes lipase.
(a) Which part of the body secretes bile ? Where is bile stored ? What is the function of bile ?
(b) What is trypsin ? What is its function ?
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?
Name the following :
(a) The process in plants which converts light energy into chemical energy.
(b) Organisms that cannot prepare their own food.
(c) Organisms that can prepare their own food.
(d) The cell organelle where photosynthesis occurs.
(e) The cells which surround a stomatal pore.
(f) An enzyme secreted by gastric glands in stomach which acts on proteins.
State whether the following statements are true or false :
(a) During respiration, the plants take C02 and release 02.
(b) Energy can be produced in cells without oxygen.
(c) Fish and earthworm exchange gases during respiration in the same way.
What are the different ways in which glucose is oxidised to provide energy in various organisms ? Give one example of each.
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
(a) What are autotrophs ? Give one example of autotrophs.
(b) What are the conditions necessary for autotrophic nutrition ?
a) How do plants obtain food ?
(b) Why do plants need nitrogen ? How do plants obtain nitrogen ?
Out of photosynthesis and respiration in plants, which process occurs :
(a) all the time ?
(b) only at daytime ?
Explain why, when air is taken in and let out during breathing, the lungs always contain a residual volume of air.
State the three common features of all the respiratory organs like skin, gills and lungs.
Give two points of differences between respiration in plants and respiration in animals.
Draw a neat diagram of excretory system of human beings and label on it:
(i) Left kidney (ii) Urinary bladder
List the three kinds of blood vessels of human circulatory system and write ¦ their functions in tabular form.
(a) Draw a sectional view of the human heart and label on it – Aorta, Right ventricle and Pulmonary veins.
(b) State the functions of the following components of transport system:
(i) Blood (ii) Lymph
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
In addition to carbon dioxide and water, state two other conditions necessary for the process of photosynthesis to take place.
(a) What is chlorophyll ? What part does chlorophyll play in photosynthesis ?
(b) (i) Which simple food is prepared first in the process of photosynthesis ?
(ii) Name the food which gets stored in plant leaves.
(a) What criteria can be used to decide whether something is alive ?
(b) What is meant by life processes ? Name the basic life processes common to all living organisms which are essential for maintaining life.