Q1. “The sex of a newborn individual in some species is largely determined genetically while in other it is otherwise.” Give three different examples to justify this statement?
Q2. If evolution is not equated with progress and further it is slow and gradual process then what could be the progressive trend in evolution? Explain giving a example.
Q3. How is the equal genetic contribution of male and female parents ensured in the progeny?
Q4. What evidence do we have for the origin of life from inanimate matter?
Q5. Do genetic combinations of mother play a significant role in determining the sex of new born?
Q6. “Variation is beneficial to the species, but not necessarily for the individual”. Give reason.
Q7. “It is possible that a trait is inherited but may not be expressed.” Give a suitable example to justify this statement.
Q8. (a) Write the evidence o the basis of which it is concluded that birds have evolved from reptiles?
(b) Insects, Octopus, Planaria and Vertebrates also possess eyes. Can these animals be grouped together o the basis of the eyes they possess? Why or why not? Give reason to justify your answer.
Q9. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists I 60%of the same population? Which is likely to have arisen earlier?
Q10. List thee factors that provide evidences in favour of evolution in organisms & state the role of each in brief?
Q11. List in tabular form distinguishing features between acquired traits and inherited traits with one example of each?
Q12. A blue flower plant denoted by BB is crossed with that of white coloured flower plant denoted by bb.
(a) State the colour of flower you would expect in their F1 generation plants.
(b) What must be the percentage of white flower plants in F2 generation if flower of F1 plants are self – pollinated?
(c) State the expected ratio of the genotypes BB in the F2 progeny?
Q13. Define the term ‘evolution’. “Evolution should not be equated with progress”? Give reason to justify this statement.
Q14. How can a pure breed be represented symbolically? Explain by taking the example of purple and white flowers?
Q15. How do Mendel’s experiments show that traits are inherited independently? Depict with the help of example.
Q16. Mendel made two different types of cross monohybrid and dihybrid. Why did he obtain different type of ratios in his experiments?
Q17. Charles Darwin came up with the idea of evolution of species by natural selection. How Gregor Mendel’s experiments support Drawin’s view?
Q18. In a population of red beetles, living o green bushes, is being eater by crows. During sexual reproduction, a green beetle is found in progeny:
(a) What is the future of new trait?
(b) Will it survive in the new habitat?
Q19. How do variations affect the evolution of those organisms that reproduce sexually?
Q20. Evolutionary relationship can be traced by study of homologons organ. Explain.
Q21. Natural selection of traits is different from artificial selection. Differentiate between the two by giving three points?
Q22. When is a recessive trait capable of expressing itself? Write its expression with respect to height of plant (genotype)?
Q23. How do Mendel’s experiments show that the
(a) traits may be dominant or recessive?
(b) traits are inherited independently?
Q24. What are fossils? How are they formed? Describe in brief two methods of determining the age of fossils. State any one role of fossils in the study of the process of evolution.
Q25. Name any five vegetables generated from a common ancestor through artificial selection rather than natural selection. Also mention the features for which each vegetable is selected.
Q26. How is the sex of the child determined in human beings?
Q27. What is speciation? List four factors that could lead to speciation, which of these cannot be a major factor in the speciation of a self – pollinating plant species explain?
Q28. A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits- bold A or O is dominant? Why or why not?