12850.Cortex is the region found between
endodermis and vascular bundle
epidermis and stele
pericycle and endodermis
endodermis and pith
Explanation:
Sequence from outside to inside in T.S. of stem is epidermis, hypodermis, cortex, endodermis, stele (pericycle + vascular tissues + pith) hence cortex is present between epidermis & stele.
Sequence from outside to inside in T.S. of stem is epidermis, hypodermis, cortex, endodermis, stele (pericycle + vascular tissues + pith) hence cortex is present between epidermis & stele.
12851.The balloon-shaped structures called tyloses
are linked to the ascent of sap through xylem vessels
originate in the lumen of vessels
characterize the sapwood
are extensions of xylem parenchyma cells into vessels
Explanation:
Tyloses are ballon like parenchymatous ingrowth in vessels adjacent to xylem vessels and tracheids of the heartwood. They inhibit transportation of water & minerals in xylem.
Tyloses are ballon like parenchymatous ingrowth in vessels adjacent to xylem vessels and tracheids of the heartwood. They inhibit transportation of water & minerals in xylem.
12852.A non-proteinaceous enzyme is
deoxyribonuclease
lysozyme
Ribozyme
ligase
Explanation:
Ribozyme is non-proteinaceous enzyme as it is an RNA that acts as a catalyst during protein synthesis.
Ribozyme is non-proteinaceous enzyme as it is an RNA that acts as a catalyst during protein synthesis.
12853.Select the mismatch.
Methanogens-Prokaryotes
Gas vacuoles-Green bacteria
Large central vacuoles-Animal cells
Protists-Eukaryotes
Explanation:
Animal cells do not contain large central vacuole, their vacuole is poorly developed or absent.
Animal cells do not contain large central vacuole, their vacuole is poorly developed or absent.
12854.Select the wrong statement.
Mycoplasma is a wall-less microorganism.
Bacterial cell wall is made up of peptidoglycan.
Pili and fimbriae are mainly involved in motility of bacterial cells.
Cyanobacteria lack flagellated cells.
Explanation:
Motility is performed by flagella only in bacterial cells while fimbriae provide attachment to base and pili forms conjugation tube during conjugation.
Motility is performed by flagella only in bacterial cells while fimbriae provide attachment to base and pili forms conjugation tube during conjugation.
12855.A cell organelle containing hydrolytic enzymes is
mesosome
lysosome
microsome
ribosome
Explanation:
Hydrolytic enzyme containing vesicle is called lysosome. Lysosomes contain about 40 - 50 hydrolytic enzymes like lipase, protease etc.
Hydrolytic enzyme containing vesicle is called lysosome. Lysosomes contain about 40 - 50 hydrolytic enzymes like lipase, protease etc.
12856.During cell growth, DNA synthesis takes place in
M phase
S Phase
G1 phase
G2 phase
Explanation:
DNA Polymerase enzyme is synthesized in G1 phase but activates in S phase hence DNA replication takes place in S phase in the presence of DNA polymerase.
DNA Polymerase enzyme is synthesized in G1 phase but activates in S phase hence DNA replication takes place in S phase in the presence of DNA polymerase.
12857.Which of the following biomolecules is common to respiration-mediated breakdown of fats, carbohydrates and proteins?
Acetyl CoA
Glucose-6-phosphate
Fructose 1,6-bisphosphate
Pyruvic acid
Explanation:
Acetyl CoA is common intermediate of fats, carbohydrates & proteins during aerobic respiration.
Acetyl CoA is common intermediate of fats, carbohydrates & proteins during aerobic respiration.
12858.A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap?
Absence of sugar
Acidic
Alkaline
Low refractive index
Explanation:
Phloem sap is alkaline due to actively pumping of protons from companion cells to the outer cells.
Phloem sap is alkaline due to actively pumping of protons from companion cells to the outer cells.
12859.You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?
Gibberellin and abscisic acid
IAA and gibberellin
Auxin and cytokinin
Auxin and abscisic acid
Explanation:
Auxin and cytokinin ratio regulates the growth of root & shoot as low concentration of Auxin and cytokinin ratio promotes shoot growth while higher ratio promotes root growth.
Auxin and cytokinin ratio regulates the growth of root & shoot as low concentration of Auxin and cytokinin ratio promotes shoot growth while higher ratio promotes root growth.
12860.Phytochrome is a
chromoprotein
flavoprotein
glycoprotein
lipoprotein
Explanation:
Phytochrome is a blue cytoplasmic chromoprotein in leaves.
Phytochrome is a blue cytoplasmic chromoprotein in leaves.
12861.Which is essential for the growth of root tip?
Mn
Zn
Fe
Ca
Explanation:
Calcium helps in meristematic activity in root tips.
Calcium helps in meristematic activity in root tips.
12862.The process which makes major difference between C3 and C4 plants is
respiration
glycolysis
Calvin cycle
photorespiration
Explanation:
Photorespiration differentiates C3 plants from C4 plants due to having high CO2 concentration around RuBP in bundle sheath cells whereas photorespiration is negligible or absent in C4 plants.
Photorespiration differentiates C3 plants from C4 plants due to having high CO2 concentration around RuBP in bundle sheath cells whereas photorespiration is negligible or absent in C4 plants.
12863.Which one of the following statements is not correct?
Water hyacinth, growing in the standing water, drains oxygen from water that leads to the death of fishes.
Offspring produced by the asexual reproduction are called clone.
Microscopic, motile asexual reproductive structures are called zoospores.
In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem.
Explanation:
Plantlets always arise from nodes of stem or modified stem. Potato, Banana and ginger plants arise from axillary buds present in the nodes.
Plantlets always arise from nodes of stem or modified stem. Potato, Banana and ginger plants arise from axillary buds present in the nodes.
12864.Which one of the following generates new genetic combinations leading to variation?
Nucellar polyembryony
Vegetative reproduction
Parthenogenesis
Sexual reproduction
Explanation:
New genetic combination develops after sexual reproduction due to following reasons
(1) Crossing over during gamete formation
(2) Chance combination of gametic fusion
New genetic combination develops after sexual reproduction due to following reasons
(1) Crossing over during gamete formation
(2) Chance combination of gametic fusion
12865.Match Column-I with Column-II and select the correct option using the codes given below :
Codes:
a b c d
| Column-I | Column-II |
|---|---|
| a. Pistils fused together | (i) Gametogenesis |
| b. Formation of gametes | (ii) Pistillate |
| c. Hyphae of higher Ascomycetes | (iii) Syncarpous |
| d. Unisexual female flower | (iv) Dikaryotic |
Codes:
a b c d
(iii) (i) (iv) (ii)
(iv) (iii) (i) (ii)
(ii) (i) (iv) (iii)
(i) (ii) (iv) (iii)
Explanation:
Correct match will be as follows :
(a) Pistils fused together → (iii) syncarpous.
(b) Formation of gametes → (i) gametogenesis.
(c) Hyphae of higher Ascomycetes → (iv) Dikaryotic
(d) Unisexual female flower → (ii) Pistillate
Correct match will be as follows :
(a) Pistils fused together → (iii) syncarpous.
(b) Formation of gametes → (i) gametogenesis.
(c) Hyphae of higher Ascomycetes → (iv) Dikaryotic
(d) Unisexual female flower → (ii) Pistillate
12866.In majority of angiosperms
a small central cell is present in the embryo sac
egg has a filiform apparatus
there are numerous antipodal cells
reduction division occurs in the megaspore mother cells
Explanation:
Megaspore mother cells divide by meiosis to form megaspores.
Megaspore mother cells divide by meiosis to form megaspores.
12867.Pollination in water hyacinth and water lily is brought about by the agency of
bats
water
insects or wind
birds
Explanation:
Water hyacinth and water lily are hydrophytes but they are pollinated by insects.
Water hyacinth and water lily are hydrophytes but they are pollinated by insects.
12868.The ovule of an angiosperm is technically equivalent to
megaspore
megasporangium
megasporophyll
megaspore mother cell
Explanation:
Ovule is an integumented megasporangium. Carpel is the megasporophyll.
Ovule is an integumented megasporangium. Carpel is the megasporophyll.
12869.Taylor conducted the experiments to prove semiconservative mode of chromosome replication on
E. coli
Vinca rosea
Vida faba
Drosophila melanogaster
Explanation:
Meselson and Stahl performed experiment on E. coli to confirm semiconservative method of DNA replication.
Meselson and Stahl performed experiment on E. coli to confirm semiconservative method of DNA replication.