A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
In unicellular organisms the entire body of the organism is in contact with the environment hence exchange of materials can take place but, in multicellular organisms the entire body of the organism is not in contact with the environment and hence simple diffusion is not helpful.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
Name the final product/products obtained in the anaerobic respiration, if it takes place :
(a) in a plant (like yeast).
(b) in an animal tissue (like muscles).
Draw a neat diagram of excretory system of human beings and label on it:
(i) Left kidney (ii) Urinary bladder
(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.
(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 ?
Fill in the following blanks with suitable words :
(a) The organs of respiration in man are the…………..
(b) The actual exchange of gases takes place in the………… of the lungs.
(c) ………………in the lungs provide a very large surface area for gaseous exchange.
(d) Yeast undergoes……….. respiration whereas Amoeba undergoes………….. respiration.
(e) Gills are the breathing organs in…………..
State the three common features of all the respiratory organs like skin, gills and lungs.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Write correct sequence of four steps of method for the preparation of temporary mount of a stained leaf peel.
(a) Draw a diagram to show open stomatal pore and label on it:
(i) guard cells
(ii) chloroplast
(b) State two functions of stomata.
(c) How do guard cells regulate the opening and closing of stomatal pore?
(a) What is meant by breathing? What happens to the rate of breathing during vigorous exercise and why?
(b) Define translocation with respect to transport in plants. Why is it essential for plants? Where in plants are the following synthesised?
(i) Sugar (iii) Hormone
Which of the following type of energy is used by living organisms to perform vital life processes ?
Kinetic energy, Chemical energy, Potential energy, Nuclear energy
What is the name of those cells in the leaf of a plant which control the opening and closing of stomata?
In the lungs :
(a) what substance is taken into the body ?
(b) what substance is removed from the body ?
What type of respiration takes place in human muscles during vigorous physical exercise ? Give reason for your answer.
Describe the process of respiration in the following parts of a plant :
(a) Root (b) Stem (c) Leaves
Name the correct substrates for the following enzymes
(a) Trypsin (b) Amylase (c) Pepsin (d) Lipase
(a) Name the pigment in leaves which absorbs sunlight energy.
(b) What is the colour of this pigment ?
What is the scientific name of the animals which are :
(i) only meat eaters ?
(ii) only plant eaters ?
(iii) both, plant and meat eaters ?
Arrange the following processes involved in the nutrition in animals in the correct order (in which they take place):
Assimilation, Egestion, Ingestion, Absorption, Digestion