REVIEW QUESTIONS

Our Environment
1.What do you mean by Environment?

2.What is an ecosystem?

3.What are biodegradable substances? Give two examples.

4.What are non - biodegradable substances? Give two examples.

5. Name the two basic components of an ecosystem.
6.Name any three biotic components.
7.Name the a biotic components of an ecosystem.

8. Name some naural ecosystem.

9. Name some man made ecosystem.

10.What are producers? Give example other thangreen plants?

11. What are consumers?Give two examples.

12.What are Herbivores?Give two examples.

13. What areCarnivores?Give two examples.

14.. What areOmnivores?Give two examples.

15. What are decomposers? How do decomposers create a balancein the environment

or

What is the role of decomposers in the ecosystem?

or

Explain how will it affect the environment if the decomposers are removed from the ecosystem.

16. What is a food chain?

17. What are the steps of food chain called?

18. Define food web?

19. Write the food chain operated in a fresh water pond. Mention the food habit of each trophic level.

20. Give an example of a grassland food chain consisting of four organisma at different trophic levels. Give the scientific term used to indicate the first and third trophic level.

21. Draw schematic diagrams of a food chain and a food web.

22.Describe with the help of diagram show energy flows through different trophic levels in a food chain.

23. What will happen if we kill all the organisms in one trophic level?

24. Differentiate between food chain and food web. Give suitable examlples of each.

25. Why we say energy flow in the biosphere is unidirectional?

26. Which food chain are advantageous in terms of energy? Support your answer giving one example.

27. Consider the food chain. Grass-----Deer------Lion What will happen if lions are removed from the above food chain?

28. The amount of energy that will be available to the plants from the sun is 20,000 J. Calculate the amount of energy available to the lion in the following food chain.
Plant----Deer----Lion

29.Calculate the amount of energy that will be available to fish in the following food chain, if 10,000 J of energy is available to small algae from the sun.Small algae---- Zooplankton------ Fish-----Big fish

30. A food chain consists of the following members. If the last member recieves 30 J of energy, make a diagrammatic representation to show the flow of energy.
Snake, Vulture, Plants, and Rat

31. Why number of trophic levels in a food chain is not more then 4 or 5.

32. What is a ten percent law?

33. How will you justify that "vegetarian food habits give us more calories"? Represent it with the help of a 3 step food chain.

34.What is biological magnification?

35. Explain the process of biological magnification?

36. If a harmful chemical enters a food chain comprising snakes, peacock. mice and plants. Which of these organisms is likely to have the maximum concentrations of this chemical in its body.Give reason.

37.What is Ozone?

38. What is the importance of ozone layer?

39.What is ozone depletion?

40.State the effects caused by the depletion of the layer?

41. Give the name of the chemicals which are responsible for thinning of ozone layers.

Assignment-HERIDITY AND EVOLUTON

1. What is heredity? 

The transfer of characters from parents to the next generation. 

2. What is variation?

The tendency of an organism differ from each other is called variation

3. Name the plant on which Mendel performed his experiment? 

Pea plant 

4. Who is called “Father of Genetics”?

Gregor Johann Mendel 

 5. Why did Mandel select pea plant for his experiment? 

1. Pea plant is easy to grow.  

2. Life cycle of pea plant is very short.

3.Controlled breeding is possible.

4. Pea plant shows contrasting pair of characters.

Tall plant.         Short plant

Violet.            White coloured flowers 

Round seeds.   Wrinkled seeds

Yellow.           Green coloured seeds 

6. What are the basic steps of Mendel’s experiment?

 7. Name any four contrasting traits studied by Mendel in garden pea plant.

plant

 8. How do Mendel’s experiments show that traits may be dominant or recessive? 

9. How do Mendel’s experiments show that traits are inherited independently? 

10 What term did Mendel use for what we now call the genes? 

11. Mendel crossed true breeding plants of terminal flower (AA) and axillary (aa) flowers. He found plants of terminal flower appeared in F1 generation. He also carried out F2 generation. Which trait is dominant? What would be the ratio in F2 generation? Show the cross. 

12. The gene for red hair is recessive to the gene for black hair. What will be the hair colour of a person if he inherits a gene for red hair from his mother and a gene for black hair from his father? 

13. In humans, if gene B gives brown eyes and gene b gives blue eyes what will be the colour of eyes of the persons having the following combination of genes? 1) Bb 2) Bb 3) BB

 14. What are genes where are they located in our body?

 15. What do dominant genes and recessive genes mean? Give an example of each 

16. Explain how, characteristic (or traits) are inherited through genes? 17. Study the given data and answer the question following the data. Parental plants cross fertilised and seeds collected 1. Male parent always bore red flowers and female parents always had white flowers 2. 330 seeds sown and observed 3. All 330 gave red flowers in F1 generation 4. Out of 44 seeds 33 seeds gave plants with red flowers and 11 seeds gave plants with white flowers in F1 generation 1. What is the term for this type of cross? 2. What does the data of the column marked F1 indicate? 3. Express the genotype of the a) parents b) F1 progeny c) F2 progeny 18. The genotype of green-stemmed tomato plants is denoted as GG and that of purple-stemmed tomato plants as gg. When these two are crossed, 1. What colour of stem would you expect in their F1 progeny? 2. Give the percentage of purple-stemmed plants if F1 plants are self-pollinated. 3. In what ratio would you find the genotype GG and Gg in the F2 progeny? 

19. How many X – chromosomes are present in the cells of normal female? 20. How many types of gametes do a male produce? 

21. How is the sex of a child determined?

 22. In humans genetically the father or mother determines the sex of a child? 

23. What will be the sex of a child who inherits X- chromosome from the father? 

24. If a sperm carrying Y- chromosome fertilizes an ovum that carries X chromosome what will be sex of the born child?

 25. If a sperm carrying X- chromosome fertilizes an ovum that carries X chromosome what will be sex of the born child? 

26. Name one reptile in each case where higher incubation temperature leads to the development of: a. Male progeny b. Female progeny 

27. Name an animal in which individuals can change sex? What does this indicates? 

28. What is meant by acquired and inherited traits? Explain with one example each. 

29. Why are the traits acquired during the lifetime of an individual not inherited?

 30. Define evolution.

 31. Who gave the idea of evolution of species by natural selection? 

32. Name the various tools of tracing evolutionary relationships which have been used for studying human evolution. 

33. What are homologous organs? Give one example of it. 

34. What are analogous organs? Give one example of it. 

35. Why are wings of birds and bats called as analogous organs? 

36. The forelimbs of frog, reptiles, birds, and a man show the same basic design of bones. What name is given to such organs? 

37. What are fossils? Give any three examples 

38. Explain importance of the fossils in deciding the evolutionary relationships? 

39. How the age of fossils can be estimated? 

40. Answer the following on the basis of the figure given on the page no. 

1 Why the number of green beetle increased in 1st  case? 

2 Why the number of green beetle increased in 2nd case? 

3 What is the cause of evolution in 1st and 2nd case? 

41 What is genetic drift? 

42 What is natural selection? 

43. Is there evolution occurring in the 3rd case? 

44 What is speciation? 

45. How is a new species formed? 

46. What are the factors responsible for speciation? 4

7 Explain why evolution can cot be said to progress from lower forms to higher forms? 

48. How will you conclude that birds are closely related to reptiles? 

49.Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics? 

50.Why are human beings who look so different from each other in terms of size, colour, and looks said to belong to the same species?

 51.What is artificial selection?

 52.How do five varieties of vegetables produced from wild cabbage by the process of artificial selection?