Saturday, 25 April 2015

CHAPTER NO-20 CHROMOSONE & DNA Jhang

CHAPTER NO-20
CHROMOSONE & DNA
Topics:introduction, types of chromosome, composition of chromosome, theory of inheritance, DNA as hereditary material,
Total Marks: 25                                                                                                                                                 Time: 35 Mins

Q.1:    Each question has four possible answers. Select the correct answer:                                                         7
1)
Structure composed of eight histone proteins and coiled DNA duplex is called:
(a)nucleotide
(b)nucleoside
(c)nucleosome
(d)all of these
2)
Role of choromosome in heredity was first determined by :
(a)Karl Correns
(b)Morgan
(c)Chargaff
(d)Franklin
3)
A typical human chromosome contains nucleotudes:
(a)140 million
(b)1.4 x 108
(c)46 million
(d)both a and b
4)
Number of chromosomes in honeybee is:
(a)32
(b)40
(c)12
(d)46
5)
Positive charge of histone proteins are due to amino acids named:
(a)arginine
(b)lysine
(c)valine
(d)both a and b
6)
The chromatin material which remains condensed throught is called:
(a)heterochromatin
(b)euchromatin
(c)chromatid
(d)centromere
7)
Particular array of chromosomes that an individual possosses is called:
(a)karyokinesis
(b)cytokinesis
(c)karyotype
(d)homologue

Q.2:    Write short answers of the following questions?                                                                                                7x2 = 14


  1. Explain the telocentric and sub metacentric  shapes of chromosomes.
  2. Explain the structure of nucleosome.
  3. Define heterochromatin and euchromatin.
  4. Define transformation.
  5. Write down the chemical composition of chromosome.
  6. Describe the first evidence regarding DNA as hereditary material.
  7. Give the list of five living organisms with their chromosome.



Long Question
Q.3:        Define transformation and give Chase Martha’s evidence regarding transformation.                       (4)
               








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