Botany 5th Sem Honours 2015 Question Paper

September 23, 2020

1 Answer the following (any ten ). 1x10=10

(a)What is cloning vector ?

(b)What is cybrid ?

(d) Where do you find Christmas tree configuration ?

(e) What is binary vector ?

(f) What is Chargaff's rule ?

(g) What is meant by degeneracy of genetic code ?

(h) What is somatic seed ?

(i)What is hardening of in vitro regenerants ?

(j) What is autophagosome ?

(k) Why are two strands of DNA called antiparallel ?

(l) What is usar soil ?

(m) What is layerage ?

(n) What are the important comonents of a greenhouse ?

(o) What is goodness of fit ?

2 Illustrate the organization of nucleus with special emphasis on nuclear pore complex and nucleolus . How does nuclear membrane disappear and reappear in cell division ? What are the differences between prokaryotic and eukaryotic ribosomes ? (5+3+2)+3+2=15

Or,

What are the different stages of cell cycle ? Discuss the role of MPF in cell cycle . How many sister chromatids do you find in pre-synthetic and post-synthetic stages of cell cycle if the chromosome number is 10 ?Name some cells that permanently remain at G zero stage . 3+6+3+3=12

3 Differentiate between autosomes and sex chromosomes. What is sex -linked inheritance? Give some examples of sex-linked recessive genes that are deleterious in humans . Illustrate Stern's experiment for cytological detection of crossing over . 3+2+2+8=15

In humans IA ,IB ,IO alleles are associated with ABO blood type. What henotype and ratio are expected from the following?

(i) IA IA x IB IB

(ii) IA IB x IO IO

(iii) IAIO X IBIO

(iv)IAIO x IO IO

What are Epistasis and gene interaction ? Define expressivity and penetrance . (2x4)+4+3=15

4 What are the basic steps in prokaryotic transcription ? What is the importance of sigma factor ? How does termination of transcription occur ? Add a note on B model of DNA. 4+2+1+4+4=15

What is inducible operon ? Mention the role of operator , repressor and promoter in lac operon . Predict the products of structural genes of lac operon in the following cases:

(i) When lactose is added in the medium.

(ii) When lactose is absent in the medium .

Give suitable illustrations of these events .2+(2+2+2)+2+5=15

5.What do you mean by de-differentiation ? What is the significance of embryo culture ? Write the steps of in vitro regeneration with illustrations.2+2(2+2)+(3+4)=15

What is restriction endonuclease ? Which type of RE is mostly used in recombinant DNA technology ? What is C-DNA library ? How is it conctructed ?Enumerate the steps involved in Agrobacterium mediated plant transgenesis .2+1+2+4+6=15

6. What is male sterility ? Explain the different systems of male sterility with suitable examples & illustrations. Mention it's significance.2+(4+4+4)+1=15

Or,

Define mean ,mode & mmedian .What is Student's t-test ? Heights of two varieties of wheat plants are given below. Find out whether the differences in height of the plant varieties are significant or not :

Variety

A. B. Height (in cm)

22. 25 cm

24. 24 cm

20. 26 cm

19. 27 cm

21. 25 cm

23. 28 cm

24. 24 cm

21. 26 cm

20. 25 cm

22. 25 cm

(t value for 18 degrees of freedom at 5% probability is 2.101)

7. What is grafting ? How does it differ from budding ? Describe the methods of prunning of stems of:

(i) woody plant

(ii) herbaceous plant.

Mention the significance of prunning. 2+2+(4+4)+3=15

Or,

What do you mean by seed priming ? Describe the different methods of scarification in breaking seed dormancy . What are pachymorh and letomorph in storage organ? What do you mean by clay loams and sandy loams ? 2+6+3+4=15