Q1. What is the importance of classification?
Ans. Classification is important because:
(a) Classification makes the study of wide variety of organisms, systematic and easier.
(b) It projects a picture of all organisms and their interrelation with each other.
(c) It provides a base for the study of other branches of biology.
(d) It is useful in the study of ecology, which deals with the inter-relation of an organism with their environment.
(e) It helps to establish a hierarchy of groups of organisms.
Q2. What are the characteristic features of mammals?
Ans. Characteristics features of mammals:
(a) Body is covered with hair.
(b) Skin is provided with sweat and sebaceous glands.
(c) Heart is four-chambered.
(d) Fertilization is internal.
(e) Females have mammary glands to produce milk to nourish their young ones.
(f) External ear—pinna present.
(g) Eyes have eye lids.
(i) Respiration through lungs.
(j) Body cavity divided into thorax and abdomen by muscular diaphragm.
Q3. What are the characteristic features of reptiles?
Ans. The characteristics of reptiles:
(a) Dry, scaly and impermeable skin.
(b) Respiration through lungs.
(d) Internal fertilization.
(e) Heart is three chambered.
(f) Two pairs of pentadactyl limbs are present.
Q4. What are the basis for classification of organisms?
Ans. The basis for classification are:
(a) Presence or absence of nucleus.
(b) Organisms are unicellular or multicellular.
(c) Level of organisation.
(d) Autotrophic or heterotrophic mode of nutrition.
(e) Of the organisms that perform photosynthesis (Plants), their level or organisation of the body.
(f) Of the animals, how does the individuals body develop and organise its different parts.
Q5. Give the classification of plant kingdom.
Q6. Give the characteristics of flat worms, round worms and segmented worm. Give their phylum.
|Flat worms||Round worms||Segmented worm|
|Dorsoventrally flat, i.e., flat body from top to bottom.||Body is cylindrical.||Body is segmented from head to tail.|
|No true body cavity.||Pseudocoelom (Sort of body cavity).||True body cavity.|
|Mostly hermaphrodite, i.e., male and female sex organs present in the same individual.||Sexes are separate.||May be unisexual or bisexual.|
Q7. Differentiate (5 points) between monocot and dicot plants.
|Monocot Plants||Dicot Plants|
|1. Fibrous root system||Tap root system|
|2. Parallel venation||Reticulate venation.|
|3. Seeds with one cotyledon||Seeds with two cotyledons|
|4. Vascular bundles are scattered.||Vascular bundles are arranged in rings.|
|5. Flowers are trimerous||Flowers are pentamerous or tetramerous|
Q8. Give the outline classification of animal kingdom.
Q9. List four distinguishing features between porifera and coelenterate animals.
|Porifera Animals||Coelenterate Animals|
|1. These organisms have holes (pores) all over their body.||These organisms have body cavity called coelenteron with a single opening.|
|2. Their body is made up of single layer of cells.||Their body is made up of two layer of cells.|
|3. The body design of these animals have very minimum differentiation and division into tissues.||They show more body design differentiation.|
|4. These have a characteristic canal system to helps in circulating water through the body to bring in food and oxygen.||These have a characteristic feature of cavity in the body.|
Q10. Fill in the following table to compare bryophytes, ferns, gymnosperms and angiosperms.
|Flowers and Fruits|
|Mode of transfer of male gamete|
|Type of fertilization|
|Flowers and Fruits||No||No||No||Yes|
|Seeds||No||No||Yes - naked||Yes - covered|
|Mode of transfer of male gamete||Moisture||Moisture||Wind||Wind, animals, birds, insects|
|Type of fertilization||Normal||Normal||Normal||Double|
Q11. Give reason to justify the following statements:
(i) Platypus and echidna lay eggs but are considered as mammals.
(ii) Crocodiles have four chambered heart but are still reptiles.
Ans. (i) Mammals show the following characteristics: Warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, females secrete milk for the nourishment of the young, and (typically) give birth to live young ones. Platypus and echidna shows all the other characteristics except they lay eggs
(ii) Reptiles show the following characteristics: They are distinguished by having a dry scaly skin and typically laying soft-shelled eggs on land. Crocodile shows all the other characteristics except it has four chambered heart like mammals.
Q12. Explain different forms of pollination and seed dispersal and also talk about the importance of co-evolution in animals and plants.
Ans. Pollination can occur by insects, birds, mammals etc.
For this the flowers need to be colorful and attractive, have good fragrance or may be bad odour in few. The flowers should also have more nectar.
The animals need to be able to see colors, get attracted to the nectar and smell the flower.
Seed dispersal: The fruit and seeds serve as a food to many animals. The seeds that are hard does not get digested in the animals body and is removed as waste. Some of the seeds have special structures so they stick to the body of the animals and are transferred.
The co-existence of plants and animals is seen in the above explanation where plants get pollinated and the seeds get dispersed only because of animals