ORIGIN-AND-EVOLUTION-OF-LIFE-QUIZ-4

BIOLOGY ORIGIN AND EVOLUTION OF LIFE  QUIZ-4

Dear Readers,

NEET is the most famous and important medical entrance examination held in our country. This exam is an objective type, an offline test which includes 4 sections namely– Physics, Chemistry, Botany, and Zoology. The maximum marks that can be scored are 720 marks and have 180 questions. About half of the paper consists of questions from Biology, as the NEET exam essentially focuses on capacitating students to go for seats in medical courses. One of the most significant and crucial sections in the NEET exam is of Biology. It comprises of theories, descriptions, discoveries, diagrams, definitions, explanations of differences, and relations. The majority of the topics covered in the NEET syllabus are from the NCERT syllabus of Class 11 & 12 and other related sources become part of the rest of the syllabus. Clear Exam curates a list of articles selected by professionals who recommend the highly vital topics for NEET exams. The table below takes you directly to the respective topic where the in-depth article and the MCQs are available for an easy and productive learning experience. Prior to solving NEET question papers or practicing mock tests, you must ensure to study the basic concepts in NEET and practice a few sample questions related to this exam. Students will be covered for all their studies as the topics are available from basics to even the most advanced..

Q1. Flippers of seal are

•  Modified forlimbs
•  Modified hindlimbs
•  Modified gill
•  Modified fins

Solution
(a) Flippers of the seal are the modified from of forelimbs. These are the examples of homologous organ

Q2.Half-life of ¹⁴ C is …A… material used in determining the age of fossil is …B… . Here A and B refers to

•  A-5568 years; B-radioactive carbon
•  A-10,000 years; B-carbon
•  A-1000 years; B-sulphur
•  A-2000 years; B-iodine

Solution
(a) ¹⁴ C used as a substrate for determining the age of fossils. The process involved is termed do carbon dating

Q3.  The variation in the natural selection is on, it is due to the random mutations. What does this imply about the natural selection?

•  Natural selection is a random process
•  Natural selection is nevertheless a directed process.
       The likelihood one variant will be favoured
       in a given environment over another is predictable,
       even if the origin is not
•  Natural selection is a hypothetical process
•  None of the above

Solution
(b) The variations of the natural selection are quite common. It is due to the random mutations. Except this, the natural selection is nevertheless is a directed process. The one liklihood one variant will be favoured in a given environment over another is predictable but their origin is uncertain and unpredictable

Q4. Darwin proposed that new species evolve from ancestral forms by the

•  Gradual accumulation of adaptations to changing environment
•  Inheritance of acquried adaptation to the environment
•  Struggle for limited resources
•  Accumulation of mutations

Solution
(a) According to Darwin, speciation is the result of gradual accumulation of adaptations to changing environment.

Q5.Mutation introduces new genes into a species and brings about the changes in

•  Phenotypes
•  Genotypes
•  Both (a) and (b)
•  None of these

Solution
(c) Mutation is the sudden inheritable change in the heredity material. Mutations bring change in the genotype as well as is the phenotype of an organism

Q6. A population exhibiting Hardy-Weinberg equilibrium possesses 25% recessive traits. Find out the frequency of recessive alleles in the gene pool of the same population

•  0.5
•  0.4
•  0.3
•  None of these

Solution
(a) Presence of recessive traits = 25% (q₁² )=25% q_1=0.5 Total allelic frequency (p+q)=1 p+0.5=1 Allelic frequency p=0.5

Q7.Primary source of allelic variation is

• Due to long periods of evolutionary changes
•  Due to abrupt mutations
•  Suddenly on earth
•  By seed dispersal

Solution
(a) Diversification in plants life appeared due to long periods of evolutionary changes. The evolutionary changes sequence is Bryophyte (thalloid, no vascular tissue)→ Pteridophytes (differentiation in vascular tissue begins) →Gymnosperms (no fruit formation) →Angiosperms (fruit present).

Q8.Darwinism explains all the following except

• Within each species, there are variations
•  Organisms tend to produce more number of offspring that can survive.
•  Offspring with better traits that overcome competition are best suited for the environment
•  Variations are inherited from parents to offspring through genes

Solution
(d) Variation was the one of the main postulates of Darwinism. Darwin recognised two types of variations-continuous and discontinuous variations, but he could not explain the inheritance of variations.

Q9.Which of the following statements is correct?

•  Organs which are different in basic structure and origin but have similar functions are called analogous organs
•  Organs which are different in basis structure and origin but have dissimilar functions are called analogous organs
•  Organs which are similar in basis structure and origin but have different functions are called analogous organs
•  None of the above

Solution
(a) Analogous organs are different in origin and basic structure but have similar functions, eg, the human eye and the eye of Octopus.

Q10. What is the difference between genetic drift and changes drift to the natural selection?

•  Genetic drift do not requires the presence of variations
•  Genetic drift rarely involves competition between the members of a species
•  Genetic drift is most effective in very large populations but natural selection operates in a small isolated population
•  There is no difference between genetic drift and natural selection

Solution
(b) Natural selection leads to the competition between the members of same species or different species but in genetic drift there is very little competition between the members of the same species