CLASS 8 WORKSHEET

CROP PRODUCTION AND MANAGEMENT

WORKSHEET  SCIENCE  CLASS-8

A. Tick  the correct option.
1. The nitrogen deficiency of soil can be made up by using the principle of:
a. Mixed cropping          b. Crop rotation
c. Multiple cropping       d. Mono cropping
2. Neem leaves constitute:
a. Bio pesticide                 b. Compost
c. Green manure                d. Fertilizer
3. The rearing and caring of animals to obtain food on large scale is:
a. Agriculture               b. Poultry farming
c. Horticulture             d. Animal husbandry
4. Excess of nitrogen fertilizers increases the:
a. Acidity in the soil        b. Alkalinity in the soil
c. Basicity in the soil       d. Salinity in the soil
5. 2, 4-D is used to kill:
a. Pests                b. Insects
c. Rodents           d. Weeds
6. Amaranthus is a:
a. Weed            b. Kharif crop
c. Rabi crop     d. Pest
7. Jute bags, silos and granaries are used to store:
a. Fruits                b. Vegetables
c. Grains               d. Chaff
8. Separation of grains from the chaff:
a. Weeding           b. Threshing
c. Harvesting        d. Winnowing

B.  Fill in the blanks.

1. __________ ensures irrigation and distribution of minerals in the field.
2. The agricultural implement used to sow seeds is called __________.
3. __________ should be removed from the food grain just before its storage.
4. The process of scattering seeds manually is called __________.
5. The process of the plantation of paddy from the nursery in the field is called __________.
6. The process in which atmospheric nitrogen is converted into nitrogen compounds is
called __________ .
7. The tremendous increase in the production of food grains is known as __________.
8. __________ is the process of crossing two or more varieties of plants having the desired
genes to obtain a variety of maximum yield.
9. __________ are not nutrient specific.
10. The storage of grains on large scale is done in __________.

CELL :STRUCTURE AND FUNCTION

A. Tick  the correct option. 
1. The cell organelle involved in photosynthesis is:
 a. Mitochondria b. Chloroplast c. Vacuole d. Lysosome 
2. The outermost layer in the plant cell is:
 a. Cell Wall b. Cell Membrane c. Plasma Membrane d. Nuclear Membrane 
3. The basic structural and functional unit of life: 
a. Tissue b. Organ c. Cell d. Nucleus
 4. This cell is a branched cell:
 a. Muscle cell b. Nerve cell c. Skin cell d. White blood cells 
5. A device that is used to see the enlarged image of very small objects: 
a. Telescope b. Microscope c. Stethoscope d. Biscope 
 B. Write ‘T’ for true and ‘F’ for false statements:
 i. The structure of plant and animal cell is the same. ( )
 ii. Cell division is required for reproduction. (  )
 iii. A vacuole occupies most of the space in a mature plant cell. ( ) iv. A group of cells performing similar function is an organ. ( ) 
 v. Cell wall regulates the exit and entry of substances. ( )
  C. Give answers  as per the explanations: 
 i. Controlling centre of the cell _________________________________
 ii. Kitchen of the cell _________________________________ 
 iii. Power house of the cell _________________________________
 iv. Site of protein synthesis _________________________________
 v. Transports materials within the cell _________________________________ 
 D. Fill in the blanks with the correct word:
 i. __________ is responsible for passing the hereditary characters (Chloroplast/Chromosome).
 ii. Amoeba is a __________ (Multicellular/Unicellular). 
 iii. The central yellow part in hen’s egg is called __________ (Yolk/Albumin).
 iv. __________ traps the solar energy which is used by the plants for photosynthesis (Chlorophyll/Chloroplast). 
 v. __________ continue to divide throughout the life (Never cells/Skin cells).