Vedas Resources

Indicate whether the following statements are True (T) or False (F). (a) Unicellular organisms have one-celled body. (T / F ) - True. (b) Muscle cells are branched. - (T / F) - False (c) The basic living unit of an organism is an organ. (T / F) - False (d) Amoeba has irregular shape. - (T / F) - True. Make a sketch of the human nerve cell. What function do nerve cells perform? Ans Nerve cells receive and transfer messages, thereby helps to control and coordinate the working of different parts of the body. Write short notes on the following: (a) Cytoplasm (b) Nucleus of a cell Ans. (a) Cytoplasm: The jelly-like substance present between the cell membrane and the nucleus. It contains various other components or organelles like mitochondria, golgi bodies, ribosomes etc. (b) Nucleus of a cell: It is an important component of the living cell. It acts as control centre of all the activities in a cell. It is generally spherical and is located in the centre of the cell. It is separated fro...

Copyrighted Material. Author Reserves All Rights What are autotrophs? Ans. Living organisms that are capable of making their own food from inorganic substances (i.e.carbon dioxide and water) using Sun's light energy, are called autotrophs. E.g. all green plants and some kind of bacteria. What are heterotrophs? Ans. Living organisms like animals and human beings that depend on other organisms for their food are called heterotrophs. What is autotrophic nutrition? Ans. The mode of nutrition by which some living organisms like green plants make their food from inorganic substances by trapping light energy from the Sun, is called autotrophic nutrition. What is heterotrophic nutrition? Ans. The mode of nutrition by which living organisms obtain their food from other living organisms, is called heterotrophic nutrition. Define photosynthesis. Ans. The process by which green plants take in organic substances (carbon dioxide and water) from the outside surroundings and conv...

The process by which all living organisms obtain and take food, utilize the food to carry out various life processes is called nutrition. Plants are the only living organisms on Earth that are capable of preparing their own food through the process of photosynthesis. A green color pigment called chlorophyll present in the leaves traps light energy from Sun. Raw materials i.e carbon dioxide and water are then converted into simple foods called carbohydrates. There are 2 major modes of nutrition in plants. These are: Autotrophic Nutrition The mode of nutrition in which living organisms make food for themselves by using simple substances is known as autotrophic nutrition (' auto ' means self and ' trophos ' means nourishment). Plants which are capable of preparing their own food are called autotrophs. Heterotrophic Nutrition The mode of nutrition in which the living organisms obtain food from other living things i.e plants is called heterotrophic nutrition (' hete...