Explain how animals in Vertebrata are classified into further subgroups.
Animals in Vertebrates are classified into five classes:
(i) Class Pisces: This class includes fish such as Scoliodon, tuna, rohu, shark, etc. These animals mostly live in water. Hence, they have special adaptive features such as a streamlined body, presence of a tail for movement, gills, etc. to live in water.
(ii) Class Amphibia: The amphibians have adopted to live both on land and water. They respire with the help of gills, lungs and through skins. They are cold - blooded animals. They lay eggs and development through larval stages. e.g : Frog, Salamander etc.
(iii) Class Reptilia: The class name refers to their creeping or crawling mode of locomotion. The body of a reptile is covered with dry and cornified skin to prevent water loss . They are cold - blooded animals. They lay eggs on land. e.g : Snakes, Chameleon etc.
(iv) Class Aves: The characteristics features of aves are the presence of feathers. Most of them have feathers. Their forelimbs are modified into wings for flight, while hind limbs have scales modified for walking and clasping. They are warm blooded and lay eggs. e.g : Crow, Pigeon etc.
(v) Class Mammalia: The most unique mammalian characteristic is presence of milk producing glands by which the young ones are nourished. Their skin has hair as well as sweat glands to regulate their body temperature. e.g : Humans, Lions, Dogs etc.
How do poriferan animals differ from coelenterate animals?
Explain the basis for grouping organisms into five kingdoms.
Which organisms are called primitive and how are they different from the so-called advanced organisms?
How do gymnosperms and Angiosperms differ from each other?
What are the major divisions in the Plantae? What is the basis for these divisions?
Give three examples of the range of variations that you see in life-forms around you.
Which do you think is a more basic characteristic for classifying organisms?
(a) the place where they live.
(b) the kind of cells they are made of. Why?
How do annelid animals differ from arthropods?
What are the differences between amphibians and reptiles?
In the hierarchy of classification, which grouping will have the smallest number of organisms with a maximum of characteristics in common and which will have the largest number of organisms?
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?
When a carpet is beaten with a stick, dust comes out of it. Explain.
What is loudness of sound? What factors does it depend on?
Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging (a) from A to B and (b) from A to C?
Diagrammatically show the difference between the three types of muscle fibres.
What is meant by the term chemical formula?
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 stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Given, g = 10 m s-2 and speed of sound = 340 m s-1.
A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.
The volume of a 500 g sealed packet is 350 cm3. Will the packet float or sink in water if the density of water is 1 g cm-3? What will be the mass of the water displaced by this packet?
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?