NEET-XII-Biology
Percentage Booster year:2024 Set:20
- #1Describe one example of adaptive radiation.
Ans : Adaptive radiation is an evolutionary process that produces new species from a single, rapidly diversifying lineage. This process occurs due to natural selection. An example of adaptive radiation is Darwin finches, found in Galapagos Island. A large variety of finches is present in Galapagos Island that arose from a single species, which reached this land accidentally. As a result, many new species have evolved, diverged, and adapted to occupy new habitats. These finches have developed different eating habits and different types of beaks to suit their feeding habits. The insectivorous, blood sucking, and other species of finches with varied dietary habits have evolved from a single seed eating finch ancestor.
- #2Can we call human evolution as adaptive radiation?
Ans : No, human evolution cannot be called adaptive radiation. This is because adaptive radiation is an evolutionary process that produces new species from a single, rapidly diversifying lineage, which is not the case with human evolution. Human evolution is a gradual process that took place slowly in time. It represents an example of anagenesis.
- #3Select the correct statement :-
(1) Gymnosperms are both homosporous and
heterosporous
(2) Salvinia, Ginkgo and Pinus all are gymnosperms
(3) Sequoia is one of the tallest trees
(4) The leaves of gymnosperms are not well adapted
to extremes of climatedigAnsr: 3Ans : (3)
- #4Which of the following is not required for any of the
techniques of DNA fingerprinting available at
present ?
(1) Polymerase chain reaction
(2) Zinc finger analysis
(3) Restriction enzymes
(4) DNA-DNA hybridizationdigAnsr: 2Ans : (2)
- #5The vascular cambium normally gives rise to :
(1) Periderm
(2) Phelloderm
(3) Primary phloem
(4) Secondary xylemdigAnsr: 4Ans : (4)
Sol.
The vascular cambium normally gives rise to secondary xylem
- #6The association of histone H1 with a nucleosome indicates :
(1) The DNA double helix is exposed
(2) Transcription is occurring
(3) DNA replication is occurring
(4) The DNA is condensed into a Chromatin FibredigAnsr: 4Ans : (4)
Sol.
During DNA condensation into a chromatin fibre the DNA wraps around histone octamer and H1 Histone
works as clip to prevent unwraping of DNA
- #8The x and y coordinates of the particle at any
time are x = 5t - ``2t^2`` and y = 10 t respectively,
where x and y are in meters and t in seconds. The
acceleration of the particle at t = 2s is :
(1) - 8 ``m/s^2`` (2) 0 (3) 5 ``m/s^2`` (4) - 4 ``m/s^2``digAnsr: 4Ans : (4)
Sol. given x = 5t - 2t2 and y = 10 t
vx = dt
dx = 5 - 4t vy = dt
dy = 0
ax = dt
dvx = - 4 ay = dt
dvy = 0
a = ax = - 4m/s2
- #9Select the correct route for the passage of sperms in male frogs :
(1) Testes → Vasa efferentia → Kidney → Bidder's canal → Urinogenital duct → Cloaca
(2) Testes → Bidder's canal → Kidney → Vasa efferentia → Urinogenital duct → Cloaca
(3) Testes → Vasa efferentia → Kidney → Seminal vesicle → Urinogenital duct → Cloaca
(4) Testes → Vasa efferentia → Bidder's canal → Ureter → CloacadigAnsr: 1Ans : (1)
Sol. From testes of frog 10-12 Vasa efferentia comes out enters into kidney and open into Bidder's canal which
leads into ureter (Urinogenital duct).& then into Cloaca.
Ureter = Urinogenital duct in male frog
- #10Life cycle of Ectocarpus and Fucus respectively are :
(1) Haplodiplontic, Haplontic
(2) Haplontic, Diplontic
(3) Diplontic, Haplodiplontic
(4) Haplodiplontic, DiplonticdigAnsr: 4Ans : (4)
Sol. Ectocarpus - Haplodiplontic (Iso morphic type)
Fucus - Diplontic life cycle.
- #11Select the mismatch :
(1) Rhizobium - Alfalfa
(2) Frania - Alnus
(3) Rhodospirillum - Mycorrhiza
(4) Anabaena - Nitrogen fixerdigAnsr: 3Ans : (3)
Sol. Rhodospirillum is a free living N2 fixing microbe.