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Plant Growth and Mineral Nutrition — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYPlant Growth and Mineral Nutrition4 Marks
Question
Column AColumn B (Organisms)
1. Symbiotic nitrogen fixationa. Nitrobacter
2. Denitrificationb. Cyanobacteria
3. Free living nitrogen fixersc. Rhizobium
4. Nitrificationd. Paracoccus
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Answer

Column AColumn B (Organisms)
1. Symbiotic nitrogen fixationc. Rhizobium
2. Denitrificationd. Paracoccus
3. Free living nitrogen fixersb. Cyanobacteria
4. Nitrificationa. Nitrobacter

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Column A (Adaptation)Column B (Type of pollination)
(1) Sticky, spiny pollen grains non-fragrant flowers(a) Anemophily
(2) Feathery stigma and versatile anther(b) Chiropterophily
(3) Presence of nectar glands and sweet smell(c) Ornithophily
(4) Dull coloured flowers with strong fragrance(d) Entomophily
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Read the following and answer any four questions from (i) to (v) given below:
While studying inheritance of characters, a teacher gave the example of inheritance of attached earlobe and hypertrichosis of the ear to her students. A man with attached earlobes and extensive hair on pinna married a woman having free earlobes. The couple had four children, one son with attached earlobes and hairy pinna, one son with a free earlobes and hairy pinna and two daughters with attached earlobes. One of the daughters married a man with free earlobes and sparse hair on pinna. Teacher said if this couple would have sons there would be equal chances for both having free or attached earlobes and sparse hair on pinnae.
  1. Attached and free earlobe are respective example of?
  1. Dominant and recessive traits.
  2. Recessive and recessive traits.
  3. Recessive and dominant traits.
  4. Dominant and dominant traits.
  1. Hypertrichosis of the ear is.
  1. X linked trait
  2. Y linked trait
  3. Autosomal dominant trait
  4. Autosomal recessive trait.
  1. If a female with attached earlobe married a male homozygous for free earlobe sparse hair on pinna then what would be the chances of daughter to have attached earlobe?
  1. 0%
  2. 100%
  3. 25%
  4. 75%
  1. If a man with attached earlobe and hairy pinna married a woman with attached earlobe then what would be the chances of son to have hairy pinna?
  1. 50%
  2. 100%
  3. 75%
  4. 0%
  1. A male with attached earlobe, sparse hair on pinna married a female with attached earlobe. Which of the following is correct regarding their progenies?
  1. All sons have a free earlobe with hairy pinna.
  2. All daughters have an attached earlobe.
  3. 50% daughters have an attached earlobe whereas 50% daughters have a free earlobe.
  4. 50% sons have attached earlobe with hairy pinna and 50% sons have a free earlobe
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Read the following and answer any four questions from (i) to (v) given below:DNA replication is a complex multistep process that requires enzymes, protein factors and metal ions. DNA replication in eukaryotes occurs in the nucleus during the S-phase of the cell cycle. It is semidiscontinuous in eukaryotes. in prokaryotes, replication takes place in the cytoplasm. DNA replication in bacteria occurs prior to fission. Nucleoid or viral chromosome is a single molecule of nucleic acid, it may be linear of circular. Nucleic acid in a virus is either DNA or RNA but never both.
  1. In viral DNA, how many origin of replication are present?
  1. Single
  2. Twice
  3. Multiple
  4. None
  1. Select the main enzyme involved in DNA replication.
  1. DNA ligase
  2. DNA dependent DNA polymerase
  3. Topoisomerase
  4. Helicase
  1. Read the given statement and select the option that correctly fill in the blanks. Enzyme (i) acts over the Ori site and unwinds the two strands of DNA by destroying (ii) bonds.
  1. (i)-Helicase (ii) Glycosidic
  2. (i)-Helicase (ii)-Hydrogen
  3. (i)-Unwindase (ii)-Phosphodiester
  4. (i)-Unwindase (ii)-Glycosidic
  1. DNA strand, built up of Okazaki fragments, is called.
  1. Lagging strand.
  2. Leading strand.
  3. Complementary strand.
  4. Parental strand.
  1. Select the incorrect statement about DNA polymerase in eukaryotes.
  1. Polymerase $\alpha$ is required for initiation of replication.
  2. When the RNA primer gets removed the gap is filled by DNA polymerase $\beta$ in eukaryotes.
  3. Polymerase $\in$ helps in elongation of lagging strand.
  4. Polymerase $\delta$ is largest and main enzyme for DNA replication in eukaryotes.
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Geological timeAnimal life
(1) Cambrian(a) Amphibians
(2) Ordovician(b) First terrestrial animals
(3) Silurian(c) Jawless fishes
(4) Devonian(d) Trilobite
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Distinguish between: DNA in prokaryotic and eukaryotic cells.
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Read the following and answer any four questions from (i) to (v) given below:
Study the two cases carefully regarding the pattern of inheritance of disease.
Case
Mother
Father
Children
Case I
With disease
Normal
Sons always with diseases
Case II
With disease
Normal
Sons and daughters could show disease
  1. Which of the following diseases is not an example of case I?
  1. Haemophilia.
  2. Colour blindness.
  3. Aa, AA, Aa, Aa, aa
  4. Night blindness.
  1. Which of the following is impossible for a case I?
  1. Carrier mother to pass the gene to her son.
  2. Diseased father to pass the gene to his daughter.
  3. Diseased father to pass the gene to his son.
  4. Carrier mother to pass the gene to her daughter.
  1. If inheritance pattern of disease is as case II and both parents are carrier of disease what are the chances of pregnancy resulting in an affected child?
  1. 25%
  2. 100%
  3. 0%
  4. 50%
  1. Disease that follows inheritance pattern as case I is linked with?
  1. Autosomes.
  2. X chromosome.
  3. Y chromosome
  4. Chromosome 21.
  1. Study the given pedigree chart showing the inheritance pattern as case II.


Study the given pedigree chart showing the inheritance pattern as case II.
  1. Aa, aa, aa, AA, aa
  2. Aa, aa, Aa, AA, Aa
  3. Aa, Aa, aa, AA, AA
  4. Aa, AA, Aa, Aa, aa
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​​​​Read the following and answer any four questions from (i) to (v) given below: Edward Wilson described diversity at all levels of biological organisation ranging from macromolecules inside the cells to biomes. It is of three inter-related hierarchial levels-genetic diversity, species diversity and conununity ecosystem diversity. Species diversity is the variety in the number and richness of the species of a region. For example, the Western ghats have a greater amphibian species diversity than the Eastern ghats.
  1. The number of species per unit area is called.
  1. Species evenness.
  2. Species richness.
  3. Species equitability.
  4. Both (a) and (c).
  1. The table below gives the population (in thousands) of ten species (A - J) in four areas (I - IV) consisting of the number of habitats given within brackets against each. Study the table and answer the question which follows:
Area and number of habitats
Species and their population (in thousands) in the area
A
B
C
D
E
F
G
H
I
J
I(11)
23
12
0.52
6.0
-
3.1
1.1
9.0
-
10.3
II(11)
10.2
-
0.62
-
1.5
3.0
-
8.2
1.1
11.2
III(13)
11.3
0.9
0.48
2.4
1.4
4.2
0.8
8.4
2.2
4.1
IV(12)
3.2
10.2
1.1
4.8
0.4
3.3
0.8
7.3
1.3
2.1
Which are out of I to IV shows maximum species diversity?
  1. II
  2. III
  3. IV
  4. I
  1. Study the given populations and choose the correct answer in relation to species diversity.
Population
Species
Species
Individuals
Population A
I
Mammals
3
II
Birds
2
III
Amphibians
2
Population B
I
Mammals
2
II
Mammals
2
III
Amphibians
1
Population C
I
Mammals
3
II
Mammals
2
III
Mammals
4
 
Maximum diversity
Minimum diversity
(a)
Population B
Population C
(b)
Population A
Population C
(c)
Population A
Population B
(d)
Population B
Population A
  1. The concept of species diversity has two components : evenness and richness. Evenness is based on the relative abundance of species. Richness is based on the total number of species present. Diversity indices combine a measure of richness and evenness. The Simpson index (D) is calculated from the following equations:
$\text{D}=\displaystyle\sum_{\text{i}=1}(\text{n}_\text{i}/\text{N})^2$
where, n = total number of organisms of particular species
N = total number of organisms of all species
Below are data collected in two terrestrial plant conununities that represent part of a successional chronosequence. ln this case the values were measured as percent cover.
Early Successional Community
Late Successional Community
Species
Percent Cover
Species
Percent Cover
A
83
F
24
B
5
G
20
C
9
H
18
D
2
I
23
E
1
J
15
The data indicate that, relative to the early successional community, the late successional community has which of the following characteristics?
 
Species Richness
Evenness
(a)
Higher
Higher
(b)
Higher
Lower
(c)
Same
Lower
(d)
Same
Higher
  1. Select the incorrect statement regarding species diversity.
  1. It results in polymorph formation and is useful in adaptation to changes in environmental conditions.
  2. Number of individuals of different species represent species evenness.
  3. It influences biotic interactions and stability of the community.
  4. It is a trait of the community.
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Read the following and answer any four questions from (i) to (v) given below:
Cross pollination is the transfer of pollen grains from the anther of a one flower to the stigma of a genetically different flower. It is performed with the help of an external agency which may be abiotic (e.g., wind, water) or biotic (e.g., insects, birds, bats, snails). The diagram shows the carpel of an insect pollinated flower.
  1. What is the most likely reason for non germination of pollen grain Z?
  1. Pollen grains X and Y were brought to the stigma earlier, therefore, their germination inhibited the germination of pollen grain Z.
  2. Pollen grain Z was brought to the flower by wind, while pollen grains X and Y were brought to the flower by insect.
  3. Pollen grain Z lacks protrusions that allow it to adhere properly onto the stigma surface.
  4. Pollen grain Z comes from a flower of an incompatible species.
  1. Which of the following best describes the function of the pollen tube?
  1. It acts as a conduit to transport male gametes from the anther to the ovule.
  2. It acts as a conduit to transport male gametes from the stigma to the ovule.
  3. It contains key nutrients that serve to nourish the newly-formed zygote.
  4. It digests the tissues of the stigma, style, and ovary.
  1. Pollination of a flower in which the pollen is carried by an insect is called:
  1. Anemophily.
  2. Ornithophily.
  3. Entomophily.
  4. Malacophil.
  1. Refer to the given characteristics of some flowers.
  1. The stamens hang out of the flower, exposing the anthers to the wind.
  2. The pollen grains are tiny and light.
  3. The flower has a sweet scent.
  4. The flower petals are brightly colored.
  1. Pollenkitt is generally found in:
  1. Anemophilous flowers.
  2. Entomophilous flowers.
  3. Ornithophilous flowers.
  4. Malacophilous flowers.
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Distinguish between: Euchromatin and Heterochromatin.
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Read the following and answer any four questions from (i) to (v) given below:
Reerna, Jai and Ankit are suffering from autoimmune diseases of adrenal cortex, joints and thyroid gland, respectively. Their immune system failed to recognise self and non-self and started destroying their body's own proteins. They are seeking proper medical help for their conditions but their condition cannot be cured completely.
Based on the above information, answer the following questions.
  1. Select the option that correctly identifies autoimmune diseases of Reema, Jai and Ankit.
S no.
Reema
Jai
Ankit
(a)
Diabetes
Grave's disease
Rheumatic fever
(b)
Pernicious anaemia
Multiple sclerosis
Myasthenia gravis
(c)
Addison's disease
Rheumatoid arthritis
Hashismoto's thyroiditis
(d)
Systemic lupus erythematosus
Severe combined immunodeficiency disease
AIDS
  1. Reema's autoimmune condition is characterised by
  1. Undersecretion of insulin.
  2. Destruction of RB Cs and low RB C count.
  3. Undersecretion of adrenal cortex hormones.
  4. Low production of intrinsic factor required for absorption of $B_12$
  1. What do you think is the major cause of Jai's condition?
  1. Deterioration of myelin sheath around nerve cells, leading to loss of precise muscle control
  2. Destruction of heart cells, leading to weakening of entire heart wall.
  3. Destruction of beta cells, leading to undersecretion of insulin.
  4. Deposition of immune complexes of IgM, IgG and complement in joints thereby inflaming joints, destroying articular cartilage and fusing bones.
  1. How do you think Ankit's condition got diagnosed?
  1. Low level of thyroid hormone and elevated levels of TSH in Ankit's blood.
  2. Presence of antibodies against thyroid pen oxidase (TPO antibodies) in Ankit's blood.
  3. Elevated erythrocyte sedimentation rate (ESR), reduced C-reactive protein (CRP) in Ankit.
  4. Both (a) and (b)
  1. Assertion: Immunosuppressive drugs often reduce the severity of autoimmune disorders.
Reason: Monoclonal antibodies have been successfully used in the treatment of autoimmune disease.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
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