Describe double circulation in human beings. Why is it necessary?
The double circulatory system of blood flow refers to the separate systems of pulmonary circulation and the systemic circulation.
The adult human heart consists of two separated pumps, the right side with the right atrium and ventricle which pumps deoxygenated blood into the pulmonary circulation.
The oxygenated blood re-enters the left side of the heart through the pulmonary vein into the left atrium and passes to the left ventricle where it is pumped to the rest of the body. This part of the circulation is called as systemic circulation. This type of circulation is called double circulation. The advantage of a double circulatory system is that blood can be pumped to the rest of the body at a higher pressure.
State the three common features of all the respiratory organs like skin, gills and lungs.
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
(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 ?
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.
(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
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
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.
Which substance is used to remove chlorophyll from a green leaf during photosynthesis experiments ?
Name the enzyme present in human saliva. What type of food material is digested by this enzyme ?
(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 is common for Cuscuta, ticks and leeches ?
(b) Name the substances on which the following enzymes act in the human digestive system :
(i) Trypsin (ii) Amylase (iii) Pepsin (iv) Lipase
(c) Why does absorption of digested food occur mainly in the small intestine ?
(a) How do guard cells regulate opening and closing of stomatal pores ?
(b) Two similar green plants are kept separately in oxygen free containers, one in dark and the other in continuous light. Which one will live longer ? Give reasons.
(a) Name the raw materials required for photosynthesis. How do plants obtain these raw materials ?
(b) What are the various conditions necessary for photosynthesis ?
(c) Name the various factors which affect the rate of photosynthesis in plants.
What is the name of the extensions of the epidermal cells of a root which help in respiration ?
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.
(a) What is meant by aquatic animals and terrestrial animals ?
(b) From where do the aquatic animals and terrestrial animals obtain oxygen for breathing and respiration ?
Name the correct substrates for the following enzymes
(a) Trypsin (b) Amylase (c) Pepsin (d) Lipase