CBSE Board Class 11 Biology Previous Year Question Papers 2008

Biology
CLASS XI

Time   :  3hrs         Marks :  70

1.Question nos 1-5 carry one mark each
2.Question nos 6-15 carry two marks each
3.Question nos 16-25 carry three marks each
4.Question nos 26 -28 carry five marks

Answer the following:-

SECTION   A

1.Two homologous chromosomes are brought together through a characteristics ladder like structure called

2.Why did Mendel selected pea plant for his experiment? Write two reasons.

3.Write any one practical application of human blood typing.

4.How many chromosomes characterize the Down Syndrome?

5.Write the name of the book written by Theophrastus

SECTION    B

6.Differentiate between differentiated and dedifferentiated cells.

7.Why is meiosis essential in sexually reproducing organisms?

8.‘Potato is a stem and sweet potato is a root’ justify the statement.

9.Write a brief note on waxes.

10.Describe various types of placentation found in flowering plants.

11.Define test cross and reciprocal cross.

12.What is aneuploidy? Give one example.

13.How is pinnocytosis differ from phagocytosis?

14.What do you mean by phyllotaxy and placentation?

15.Describe the main features of pteridophytes.
or
            What are transgenic animals? Give an example

SECTION  C

16.How would you distinguish monocot from dicot anatomically?

17.Why is allosteric inhibition called feed back inhibition?

18.Briefly explain incomplete dominance with suitable example.

19.What do you mean by sickle cell anaemia? How is it caused?

20.Briefly explain the process of protein synthesis in eukaryotic cel.

21.Enlist the role of -   mRNA, rRNA, and tRNA in protein synthesis.

22.Draw a neat-labeled diagram of stomatal apparatus found in Dicot leaf
OR
             Draw the internal structure of male round worm nd label any four parts     

23.What are the main functions of mitochondria and nucleus?

24.Explain Lac operan

25.Write the edible part of Mango, tomato, apple

26.Describe the various steps involved in cloning
         
27.How did Harshey and Chase proved that DNA is he genetic material?
Or

            List the steps involved inrecombinant  DNA technology

28.What  semi conservative replication of DNA.     
or
            Draw and decribe sub stages of prophase I of Meiosis I