1st Year Biology Second half Book Paper

Q1. Multiple choice questions (Attempt all · 80 × 0.5 = 40)

1. The process of replacement of one community by another is divided into phases called
   1. Layers
   2. Generations
   3. Levels
   4. Seral stages
2. Long-day plants require ______ to flower.
   1. Short nights
   2. Long nights
   3. No light
   4. Continuous dark
3. Triploblastic animals have ______ germ layers.
   1. One
   2. Two
   3. Three
   4. Four
4. Darwin developed his theory in the late
   1. 1700s
   2. 1830s
   3. 1850s
   4. 1900s
5. 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.
6. The ABO blood group system was discovered by
   1. Watson
   2. Mendel
   3. Karl Landsteiner
   4. Morgan
7. The human ovary produces
   1. Sperm
   2. Ova
   3. Milk
   4. Hormones only
8. The synthesis of nitrogen fertilizers is called
   1. Industrial fixation
   2. Biological fixation
   3. Atmospheric fixation
   4. Chemical fixation
9. The most accepted theory of translocation is ______.
   1. Diffusion theory
   2. Capillary theory
   3. Osmotic theory
   4. Pressure flow theory
10. The water vascular system is characteristic of __________.
    1. Arthropods
    2. Echinoderms
    3. Annelids
    4. Molluscs
11. 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
12. The enzyme that catalyzes amino acid activation is
    1. Gyrase
    2. Peptidyl transferase
    3. RNA ligase
    4. Aminoacyl-tRNA synthetase
13. The basic unit of heredity is
    1. Chromosome
    2. DNA
    3. Gene
    4. Nucleotide
14. Which of the following hormones provides hormonal trigger to cause ovulation & release of eggs from ovary.
    1. Estrogen
    2. Testosterone
    3. Luteinizing hormon (LH)
    4. All of these
15. Hydrarch succession occurs in
    1. Desert
    2. Water bodies
    3. Mountains
    4. Rocks
16. Water potential of pure water is ______.
    1. Positive
    2. Zero
    3. Negative
    4. Variable
17. The main identifying feature of chordates is the presence of __________.
    1. Brain
    2. Notochord
    3. Gills
    4. Segmentation
18. 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
19. The genetic cause of Down syndrome is
    1. Trisomy 21
    2. Trisomy 18
    3. Monosomy X
    4. XXY condition
20. Genes located on autosomes show
    1. Sex linkage
    2. Dominant linkage
    3. Recessive linkage
    4. Autosomal linkage
21. Fertilization of the ovum normally occurs:
    1. In distal part of oviduct
    2. Along the uterine wall
    3. In proximal part of oviduct
    4. Successfully in vagina
22. 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
23. Vascular cambium produces ______.
    1. Secondary xylem and secondary phloem
    2. Cork and secondary cortex
    3. Root hairs
    4. Pith
24. True coelom is completely lined by ______.
    1. Endoderm
    2. Ectoderm
    3. Mesoderm
    4. Epidermis
25. Analogous organs arise due to :
    1. Divergent evolution
    2. Artificial selection
    3. Genetic drift
    4. Convergent evolution.
26. 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
27. The offspring of a black and white parent in polygenic inheritance is called
    1. Mulatto
    2. Albino
    3. Hybrid
    4. Epistatic
28. Which of the following is a primary organ of the female reproductive system?
    1. Vagina
    2. Ovary.
    3. Uterus
    4. Testes
29. Tropical grasslands in Pakistan typically experience which climate?
    1. Arid
    2. Monsoon
    3. Tundra
    4. Mediterranean
30. Pressure potential increases when ______.
    1. Water leaves the cell
    2. Solute decreases
    3. Cell becomes flaccid
    4. Cell becomes turgid
31. What is a radula?
    1. A spiny ribbon of tissues used for feeding in snails.
    2. A gas exchange structure in insects
    3. A stinging cell used by sea anemones to capture prey
    4. A supportive rod on the dorsal surface of chordates
32. Lamarck presented his theory in the book
    1. Origin of Species
    2. Philosophie Zoologique
    3. Evolution of Life
    4. Theory of Evolution
33. Mustard gas and nitrous gas are examples of
    1. Chemical mutagens
    2. Physical mutagens
    3. Biological mutagens
    4. Natural mutagens
34. Rh blood group system is encoded by three genes C, D and E which occupy tightly linked loci:
    1. Five
    2. Four
    3. Three
    4. Two
35. The female reproductive system includes
    1. Ureters, kidneys, vagina
    2. Urethra, cervix, rectum
    3. Seminal vesicle, uterus, vagina
    4. Ovaries, oviducts, uterus, vagina
36. What common name is often given to coral reefs because of their great biodiversity?
    1. Deserts of the sea
    2. Gardens of the sea
    3. Rainforests of the sea
    4. Mountains of the sea
37. The meristem responsible for increase in thickness of stems and roots is ______.
    1. Lateral meristem
    2. Apical meristem
    3. Intercalary meristem
    4. Primary meristem
38. The exoskeleton of arthropods is made up of __________.
    1. Calcium
    2. Cellulose
    3. Keratin
    4. Chitin
39. Comparative anatomy deals with
    1. Behaviour of organisms
    2. Similarities and differences in structure
    3. Food habits of animals
    4. Fossil study
40. The substitution of one base by another is known as
    1. Insertion
    2. Deletion
    3. Base substitution
    4. Duplication
41. In Foxglove flower, dominant epistasis is shown by
    1. D gene
    2. H gene
    3. W gene
    4. A gene
42. The process of formation of sperms is known as
    1. Oogenesis
    2. Fertilization
    3. Spermatogenesis
    4. Ovulation
43. What is the annual precipitation range for temperate grasslands in Pakistan?
    1. 200-400 mm
    2. 150-500 mm
    3. 600-900 mm
    4. 50-100 mm
44. Guard cells are the only cells of epidermis, which have:
    1. Vacuole
    2. Chloroplasts.
    3. Cytoplasm
    4. Leucoplasts
45. A land snail, a clam, and an octopus all share:
    1. Gills
    2. Embryonic torsion
    3. Mantle
    4. Radula
46. Fitness according to Darwin refers to:
    1. Number of species in a community
    2. Strength of an individual
    3. Useful variation in population
    4. Reproductive fitness of an organism.
47. Errors during meiosis or DNA replication cause
    1. Induced mutations
    2. Frame mutations
    3. Beneficial mutations
    4. Natural mutations
48. The genes located on the Y chromosome are called
    1. X-linked genes
    2. Holandric genes
    3. Dominant genes
    4. Mutant genes
49. Spermatogenesis is controlled by hormones from
    1. Liver
    2. Hypothalamus and anterior pituitary
    3. Thyroid and pancreas
    4. Adrenal glands
50. The nitrogen cycle is essential for the synthesis of
    1. Lipids and starch
    2. Amino acids and proteins
    3. Sugars and cellulose
    4. Water and salts
51. The main function of support in plants is to ______.
    1. Store food
    2. Absorb water
    3. Perform photosynthesis
    4. Keep the body erect and in shape
52. Body temperature of birds remains __________.
    1. Constant
    2. Variable
    3. Low
    4. High
53. The overproduction of offspring leads to
    1. Genetic mutation
    2. Struggle for existence
    3. Inheritance of acquired traits
    4. Adaptation failure
54. The enzyme used for RNA splicing is
    1. RNA ligase
    2. RNA polymerase
    3. DNA ligase
    4. Helicase
55. In the XY-XX type of sex determination, males are
    1. Heterogametic
    2. Homogametic
    3. Diploid
    4. Haploid
56. Which one of the following events is correctly matched with the time period in a normal menstrual cycle:
    1. Release of egg: 5th day
    2. Endometrium regenerates: 5-10 days
    3. Endometrium secrets nutrients for implantation: 11-18 days.
    4. Rise in progesterone level: 1-15 days
57. Organisms that play a crucial role in the desert ecosystem by helping recycle nutrients by feeding on dead organisms are called:
    1. Producers
    2. Herbivores
    3. Burrowers
    4. Scavengers
58. Meristematic cells have ______.
    1. Small vacuoles and thin walls
    2. Large vacuoles and thick walls
    3. Thick lignified walls
    4. No nucleus
59. Reptiles lay eggs with __________.
    1. Hard calcareous shell
    2. Soft gelatinous shell
    3. Without shell
    4. None of these
60. The main drawback of Lamarck's theory is that
    1. It ignored heredity
    2. It was supported by fossil evidence
    3. It was proved by experiments
    4. It explained genetic variations
61. The strand synthesized discontinuously away from the replication fork is called
    1. Template strand
    2. Daughter strand
    3. Lagging strand
    4. Leading strand
62. Traits controlled by more than one gene are called
    1. Monogenic traits
    2. Polygenic traits
    3. Co-dominant traits
    4. Multiple alleles
63. The phase of menstruation during which bleeding occurs is
    1. Proliferative phase
    2. Secretory phase
    3. Menstrual phase
    4. Follicular phase
64. Desert plants that have modified leaves or stems to reduce water loss through transpiration are called:
    1. Hydrophytes
    2. Mesophytes
    3. Deciduous
    4. Xerophytes
65. Solute potential is always ______.
    1. Positive
    2. Zero
    3. Negative
    4. Neutral
66. The largest phylum in Animalia is __________.
    1. Chordata
    2. Arthropoda
    3. Mollusca
    4. Annelida
67. Which one of the following phenomena supports Darwin's concept of natural selection in organic evolution?
    1. Development of transgenic animals
    2. Prevalence of pesticide resistant insects.
    3. Production of "Dolly, the sheep by cloning
    4. Development of organs from 'stem cells' for organ transplantation
68. The idea that DNA makes protein through RNA is called
    1. Central dogma
    2. Genetic theory
    3. Protein hypothesis
    4. Transcription rule
69. Phenomena of an allele of one gene suppressing the activity of allele of another gene is called:
    1. Dominance
    2. Epistasis
    3. Suppression
    4. Inactivation
70. How does a zygote differ from an ovum?
    1. A zygote is smaller
    2. A zygote consists of more than one cell
    3. A zygote has diploid number chromosomes
    4. A zygote is much larger
71. Water stored underground in porous rocks is called
    1. Reservoir
    2. Aquifer
    3. Basin
    4. Pond
72. Chemicals that regulate plant growth are called ______.
    1. Enzymes
    2. Vitamins
    3. Plant growth regulators
    4. Hormones only
73. Animals lacking tissue organization belong to ______.
    1. Eumetazoa
    2. Parazoa
    3. Bilateria
    4. Radiata
74. The process of natural selection results in
    1. No change in alleles
    2. Decrease of favourable alleles
    3. Random variation only
    4. Increase of favourable alleles
75. A permanent change in the DNA sequence is called
    1. Evolution
    2. Replication
    3. Translation
    4. Mutation
76. Multiple alleles occupy
    1. Different loci
    2. The same locus
    3. Two loci only
    4. Opposite chromosomes
77. If ruptured Matured/Graffian follicle is degenerated without forming corpus luteum, which of the following is expected?
    1. Menstruation will not occur
    2. Ovulation will not occur
    3. Pregnancy is established
    4. None of them.
78. Density is defined as
    1. Number of individuals per unit area or volume
    2. Growth rate
    3. Reproductive success
    4. Number of species in a community
79. The sugar moves through phloem is mostly in the form of :
    1. Glucose
    2. Sucrose.
    3. Maltose
    4. Lactose
80. The respiratory organs of insects are __________.
    1. Gills
    2. Lungs
    3. Tracheae
    4. Skin