Agriculture - Online Test
Q1. Apomixis means
Answer : Option D
Explaination / Solution:
Apomixis is modified form of reproduction in plants in which seeds are formed without fusion of gametes. The diploid cell of nucellus develops into an embryo giving a diploid seeds.
Q2. Phylloclade are
Answer : Option D
Explaination / Solution:
Phylloclade are green succulent stems of indefinite growth that perform thefunction of photosynthesis duet to presence of chlorophyll.
Q3. Which is the function of companion cells?
Answer : Option A
Explaination / Solution:
companion cell: any of a number of specialized parenchymal cells adjacent to a sieve tube in the phloem of flowering plants, believed to regulate the flow of nutrients through the tube.
Q4. S-shaped graph produced on plotting growth against time is called
Answer : Option A
Explaination / Solution:
S- Shaped growth curve (Sigmoid growth curve) A pattern of growth in which, in a new environment, the population density of an organism increases slowly initially, in a positive acceleration phase; then increases rapidly approaching an exponential growth rate; but then declines in a negative acceleration phase until at zero growth rate the population stabilizes.
This slowing of the rate of growth reflects increasing environmental resistance which becomes proportionately more important at higher population densities.
This type of population growth is termed ‘density dependent’.
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Q5. When water moves out of the cell and the cell membrane of a plant cell shrinks away from its cell is called
Answer : Option C
Explaination / Solution:
Plasmolysis is the process of shrinkage or contraction of the protoplasm of a plant cell as a result of loss of water from the cell.
Plasmolysis is one of the results of osmosis and occurs very rarely in nature, but it happens in some extreme conditions.
Q6. Plants with Zinc deficiency show reduced biosynthesis of
Answer : Option A
Explaination / Solution:
Plants with Zinc deficiency show reduced biosynthesis of Auxin. Auxin play most important role in growth and elongation of plants by cell division and cell differentiation.
Q7. An algae with ribbon shaped chloroplast
Answer : Option B
Explaination / Solution:
Spirogyra is an algae that have long thread like structure having ribbon shaped chloroplast. Spirogyra is found in stagnant water forming green layer around the surface called pond scum.
Q8. Name the photosynthetic pigment which can be converted to Vitamin A?
Answer : Option D
Explaination / Solution:
The photosynthetic pigment Beta-carotenes can be converted to Vitamin A. carrot contain large quantity of carotenes that can be converted into vitamin A.
Q9. The alternation of two different phases of the life cycle involving haploid and diploid stage is called
Answer : Option C
Explaination / Solution:
Alternation of generation is the cyclic change in organisms involving haploid and diploid stages. Meiotic division results into haploid stage and fusion of haploid gametes results into diploid stage.
Q10. In Mirabilis jalapa when two F1 pink flowered plants were crossed with each other, the F2 generation produced 40 red, 80 pink and 40 white flowering plants. This a case of
Answer : Option D
Explaination / Solution:
F1pink flowered plants are heterozygous. When selfing is done the genotype and phenotype develops as 1:2:1 as 40 red, 80 pink and 40 white flowering plants.
