Question 1. Why do we classify organisms?
For easier and convenient study we classify organisms.
Question 2. Give three examples of the range of variations that you see in life-forms around you.
(a) Small cat and big cow
(b) Grass and banyan tree
(c) Black crow and green parrot
Question 3. 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?
Classification based on living place is more basic as there can be wide variations in organisms living in a given place.
Question 4. What is the primary characteristic on which the first division of organisms is made?
Nature of cell is the primary characteristics on which the first division of organisms is decided. Based on this criterion life forms can be classified into prokaryotes or eukaryotes.
Question 5. On what bases are plants and animal’ out into different categories?
Mode of nutrition and presence or absence of cell walls.
Question 6. Which organisms are called primitive and how are they different from the so-called – advanced organisms?
Organisms with simple cellular structure and no division of labour are called
primitive.
Advanced organisms, like mammals have millions of cells and there are different organs and organ system for different biological functions.
Question 7. Will adiKznced organisms be the same as complex organisms? Why?
Yes, advanced organisms means greater degree of evolution which leads to more complexity.
Question 8. Whaf is the criterion for classification of organisms as belonging to kingdom Monera or Protista?
It is the presence or absence of a well defined nucleus. Monera has no nuclear membrane, while Protista shows well defined nucleus.
Question 9. In which kingdom will you place an organism which is single-celled, eukaryotic and
photosynthetic?
Protista.
Question 10. 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?
Organisms belonging to Kingdom Monera will have the small number of organisms with a maximum of characteristics in common. And kingdom Animalia will have the largest number of organisms.
Question 11. Which division among plants has the simplest organisms?
Thallophyta or algae.
Question 12. How are pteridophytes different from the phanerogams?
Pteridophytes have naked embryo and inconspicuous reproductive organ whereas — phanerogams have well-differentiated reproductive organs and covered embryo.
Question 13. How do gymnosperms and angiosperms differ from each other?
Seeds are naked in Gymnosperms and are covered in angiosperms.
Question 14. How do poriferan animals differ from coelenterate animals?
- Animals from Porifera show cellular level of organisation, while those from Coelenterata show tissue level of organisation.
- In Porifera there is no division of labour, while in Coelenterata some division of labour is seen.
- Porifera do not have coelom, while coelenterata have coelom.
Question 15. How do annelid animals differ from arthropods?
Question 16. What are the differences between amphibians and reptiles?
Question 17. What are the differences between animals belonging to the Aves group and those in the mammalia group?
Question 18. What are the advantages of classifying organisms?
Advantages of classification:
- Better categorization of living beings based on common characters.
- Easier study for scientific research.
- Better understanding of human’s relation and dependency on other organisms.
- Helps in cross breeding and genetic engineering for commercial purposes.
Question 19. How would you choose between two characteristics to be used for developing a hierarchy in classification?
Gross Character will “form-the basis of start of the hierarchy and fine character -will -form “the basis of further steps of single the hierarchy.
Example:
- Presence of vertebral column in human beings can be taken under vertebrata.
- Presence of four limbs makes them members of Tetrapoda.
- Presence of mammary glands keeps them under mammalia.
Question 20. Explain the basis for grouping organisms into five kingdoms.
Basis Of Clasiffication:
(a) Number of cells
(b) Layer of cells
(c) Presence or absence of cell wall
(d) Mode of nutrition
(e) Level Of organization
Question 21. What are the major divisions in the Plantae? What is the basis for these divisions?
Major Divisions of Kingdom plantea:
| Division | Basis of Classification |
| Thallophyta or Algae | Thallus like body |
| Bryophyta | Body is divided into leaf and stem |
| Pteridophyta | Body is divided into root, stem and leaf |
| Gymnosperm | Seed bearing, naked seeds |
| Angiosperm | Seed bearings covered seeds |
Question 22. How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?
In plants body basic structure is a major criteria based on which Thallophytes are different from Bryophytes. Apart from this absence or presence of seeds is another important criteria. Gymnosperms and angiosperms are further segregated based on if seeds are covered or not. It is clear that it is the morphological character which makes the basis for classification of plants.
In animals classification is based on more minute structural variations. So in place of morphology, cytology forms the basis. Animals are classified based on layers of cells, presence or absence of coelom. Further higher the hierarchy animals are classified based on presence or absence of smaller features, like presence or absence of four legs.
Question 23. Explain how animals in Vertebrata are classified into further subgroups.
Vertebrata is divided into two superclasses, viz. Pisces and Tetrapoda. Animals of Pisces have streamlined body with fins and tails to assist in swimming. Animals of Tetrapoda have four limbs for locomotion.
Tetrapoda is further classified into following classes:
(a) Amphibia: Are adapted to live in water and on land. Can breathe oxygen through skin when under water.
(b) Reptilia: These sire crawling animals. Skin is hard to withstand extreme temperatures.
(c) Aves: Forelimbs are modified into wings to assist in flying. Beaks are present. Body is covered with feathers.
(d) Mammalia: Mammary glands present to nurture young ones. Skin is covered with hair. Most of the animals are viviparous.
Question 24. Who wrote the book “The Origin of Species”?
Charles Darwin in 1859.
Question 25. Who proposed the classification of organisms into 5 kingdom?
Robert Whittaker (1959).
Question 26. Define species.
All organisms that <are similar to breed and perpetuate.
Question 27. Give example of the organism belonging to Monera and Protista Kingdom.
Monera—Anabaena, blue-gr^en algae Protista—Eugleno, Paramecium, Amoeba
Question 28. Name the appendages used for movement by organism belonging to Protista kingdom
Paramecium – Cilia
Euglena – Flagella
Amoeba – Pseudopodia
Question 29. What is lichen?
The symbiotic association of fungi and blue-green algae, is called lichen.
Question 30. What is symbiotic relationship?
It is a relationship between two organisms in which both of them are benefitted, e.g., fungi gets food from blue-green algae and in return blue-green gets shelter [lichens].
Question 31. What is saprophytic nutrition?
The organisms using dead and decaying organic matter as food are said to show saprophytic nutrition.
Question 32. Give simple dassificatian of plant kingdom.
Question 33. Name the plant amphibian.
Biyophyta e.g. Funaria (Moss).
Question 34. What are cryptogamae?
The plants with inconspicuous reproductive organs are called cryptogamae, e.g., fern.
Question 35. Give examples of pteridophyte.
Marsilea and Fern.
Question 36. Name the reproductive organ of plants.
Flower.
Question 37. What are gymnosperms?
The group of plants that bear naked seeds e.g., pines, deodar.
Question 38. What are angiosperms?
The group of plants with covered seeds are called angiosperms. These are flowering plants.
Question 39. What are cotyledons?
Plant embryos in seeds have structures called cotyledons. Cotyledens are also known as seed leaves.
Question 40. Name the phylum of an animals with pores on it.
Porifera e.g., sponge.
Question 41. Name the phylum of Jellyfish
Coelenterata or Cnidaria.
Question 42. What is the meaning of triploblastic?
Animals which have three layers of cells from which differentiated tissues -can be made.
Question 43. What is bilateral symmetry?
When the left and right halves of the body have same design it is called bilateral symmetry.
Question 44. What is the meaning of “cold-blooded animal”?
Those animals who show the variation in their body temperature according to the surroundings are called cold-blooded animals, e.g., fish, amphibians, reptiles.
Question 45. Name two mammals that lay eggs.
Platypus and echidna.
Question 46. Name three mammals that live in water.
Whale, platypus and Dolphins.
Question 47. Name a fish with skeleton made up of cartilage.
Shark.
Question 48. Name two fish which have skeleton made up of both bone and cartilage.
Tuna and rohu.
Question 49. Name the reptile with four-chambered heart.
Crocodile.
Question 50. Give the characteristics of Monera.
(a) Organisms are unicellular, do not have a defined nucleus.
(b) Organisms may have a cell wall or may not have cell wall.
(c) Mode of nutrition is either autotrophic or heterotrophic.
Question 51. Give the characteristics of Protista.
(a) Organsims are unicellular and eukaryotic.
(b) Use appendages for locomotion like cilia, flagella, etc.
(c) Nutrition is either autotrophic or heterotrophic.
(d) E.g., algae, protozoa.
Question 52. Give the difference between thallophyta and bryophyta.
| Thallophyta | Bryophyta |
| Body is thallus like not differentiated into -root, stem. Example: Spirogyra. | Plant Body is differentiated into stem and leaf like structures. Example: Moss. |
Question 53. What are hermaphrodites? Give two examples.
When an organism has both the sexes, i.e., it can produce both sperms and eggs are called hermaphrodites. Example: Sponges, earthworms.
Question 54. Give the difference between monocots and dicots.
| Monocots | Dicots |
| 1. Seeds with one cotyledon.2. Leaves have parallel venation.3. Root system—fibrous. | Seeds with two cotyledons.Leaves have reticulate venation.Root system—tap root. |
Question 55. Give the difference between two types of symmetry that animals show.
Symmetry—Bilateral and Radial
| Bilateral Symmetry | Radial Symmetry |
| Any organism that has same design on left and right halves of the body. Example: Earthworm, spider, cockroach. | Any organisms with a body design such that it can be divided into two equal halves from any radius. Example: Starfish sea urchin. |
Question 56. Differentiate between vertebrates and invertebrates.
| Vertebrates | Invertebrates |
| 1. Notochord is present.2. True internal skeleton present. | Notochord is absent.No true internal skeleton present. |
Question 57. Name the phylum of the following animals:
(a) Tapeworm
(b) Starfish
(c) Jellyfish
(d) Octopus
(a) Tapeworm – Flatyhelminthes
(b) Starfish – Echinodermatai
(c) Jellyfish – Coelenterata
(d) Octopus – Mollusca
Question 58. Identify the phylum for the following characteristics given:
(a) Organisms with joint appendages.
(b) Organisms are generally flat worms.
(c) Body is segmented.
(d) Skin of organisms is full of spikes.
(a) Arthropoda
(b) Platyhelminthes
(c) Ann elida
(d) Echinodermata
Question 59. State the features of all chordates.
All chrodates possess the following features:
- Have a notochord
- Have a dorsal nerve chord
- Are triploblastic
- Have paired gill pouches
Question 60. Give general characteristics of Porifera.
(a) Animals with pores all over the body.
(b) Body is not well differentiated.
(c) Non-motile animals, remain attached to solid support.
(d) Body is covered with hard outer skeleton. Example, sponges.