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.
How do annelid animals differ from arthropods?
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?
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?
Who discovered cells, and how?
Are the answers to the above questions necessarily the same or different? Why?
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?
What is osmosis?
What is the mass of—
(a) 1 mole of nitrogen atoms?
(b) 4 moles of aluminium atoms (Atomic mass of aluminium = 27)?
(c) 10 moles of sodium sulphite (Na2SO3)?
What are the various energy transformations that occur when you are riding a bicycle?
How does an Amoeba obtain its food?
When will you say a body is in
(i) uniform acceleration? (ii) non-uniform acceleration?
Make a comparison and write down ways in which plant cells are different from animal cells.
Diagrammatically show the difference between the three types of muscle fibres.