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?
What are the constituents of phloem?
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?
What is the audible range of the average human ear?
Differentiate between homogeneous and heterogeneous mixtures with examples.
What are the two forms of oxygen found in the atmosphere?
Compare all the proposed models of an atom given in this chapter.
Give the names of the elements present in the following compounds.
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate.
What is the mass of:
(a) 0.2 mole of oxygen atoms?
(b) 0.5 mole of water molecules?
What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?
The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes 168 X and 188 X in the sample?
Which organelle is known as the powerhouse of the cell? Why?
Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.