Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.
Striated muscles | Unstriated muscles | Cardiac muscles |
---|---|---|
1. The cells of striated muscles are long, cylindrical, unbranched and multinucleate. | 1. The cells of unstriated muscles are long and pointed at the ends, spindle shaped and uninucleate. | 1. The cells of cardiac muscles are cylindrical, branched and uninucleate. |
2. Many nuclei which are situated towards the periphery of muscle fibre. | 2. The cells have only one nucleus situated in the center. | 2. Each cell contains one or two nuclei situated in the center. |
Diagrammatically show the difference between the three types of muscle fibres.
What does a neuron look like?
Draw a labelled diagram of a neuron.
Complete the table:
Give three features of cardiac muscles.
Where is apical meristem found?
What are the functions of the stomata?
How many types of elements together make up the xylem tissue? Name them.
What is a tissue?
Name the following.
(a) Tissue that forms the inner lining of our mouth.
(b) Tissue that connects muscle to bone in humans.
(c) Tissue that transports food in plants.
(d) Tissue that stores fat in our body.
(e) Connective tissue with a fluid matrix.
(f) Tissue present in the brain.
Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?
State the universal law of gravitation.
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
What is meant by a pure substance?
How does the sound produced by a vibrating object in a medium reach your ear?
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water
What are canal rays?
State any two conditions essential for good health.
How is our atmosphere different from the atmospheres on Venus and Mars?
Carry out the following osmosis experiment:
Take four peeled potato halves and scoos each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.
Keep these for two hours. Then observe the four potato cups and answer the following:
(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed out portions of A and D.
A bus decreases its speed from 80 km h-1 to 60 km h-1 in 5 s. Find the acceleration of the bus.
Are the answers to the above questions necessarily the same or different? Why?
Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.
Where are proteins synthesised inside the cell?
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
How does the water kept in an earthen pot (matka) become cool during summer?
A stone of 1 kg is thrown with a velocity of 20 m s-1 across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice?
Which method is commonly used for improving cattle breeds and why?