1st Year Biology 4th Quarter Book Paper

Q1. Multiple choice questions (Attempt all · 12 × 1 = 12)

1. What is the basis for the difference in how leading & lagging strands of DNA molecules are synthesized?
   1. The origins of replication occur only at 5'end.
   2. DNA ligase works only in the 3'----5' direction
   3. Polymerase can only work on one strand at a time
   4. DNA polymerase can join new nucleotides only to the 3' end of a growing strand.
2. Darwin developed his theory in the late
   1. 1700s
   2. 1830s
   3. 1850s
   4. 1900s
3. The process of replacement of one community by another is divided into phases called
   1. Layers
   2. Generations
   3. Levels
   4. Seral stages
4. The enzyme that catalyzes amino acid activation is
   1. Gyrase
   2. Peptidyl transferase
   3. RNA ligase
   4. Aminoacyl-tRNA synthetase
5. Neo-Darwinism is the reappraisal of Darwin's theory in terms of
   1. Modern population genetics
   2. Inheritance of acquired characters
   3. Use and disuse of organs
   4. Environmental changes
6. The synthesis of nitrogen fertilizers is called
   1. Industrial fixation
   2. Biological fixation
   3. Atmospheric fixation
   4. Chemical fixation
7. The genetic cause of Down syndrome is
   1. Trisomy 21
   2. Trisomy 18
   3. Monosomy X
   4. XXY condition
8. Which of the following is not true about Lamarckism?
   1. Somatic changes are heritable
   2. There is experimental proof
   3. Organs can be modified by wish
   4. Both b and c
9. Hydrarch succession occurs in
   1. Desert
   2. Water bodies
   3. Mountains
   4. Rocks
10. In eukaryotic cells, transcription cannot begin until:
    1. The two DNA strands have completely separated and exposed the promater.
    2. Several transcription factors have bound to the promoter
    3. The DNA introns are removed from the template
    4. DNA nucleases have isolated the transcription unit
11. Analogous organs arise due to :
    1. Divergent evolution
    2. Artificial selection
    3. Genetic drift
    4. Convergent evolution.
12. Which region of Pakistan are coniferous forests primarily found in?
    1. Coastal areas
    2. Southern plains
    3. Northern mountainous areas (Himalayas and Karakoram)
    4. Western deserts