Q.1 Who is known as the 'Father of Genetics'?
Charles Darwin
Gregor Mendel
James Watson
Francis Crick
Explanation - Gregor Mendel discovered the fundamental laws of inheritance using pea plants, making him the Father of Genetics.
Correct answer is: Gregor Mendel
Q.2 Which of the following is NOT a type of RNA?
mRNA
tRNA
rRNA
dRNA
Explanation - dRNA does not exist; the major types of RNA are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).
Correct answer is: dRNA
Q.3 In humans, the sex of a child is determined by the:
Mother
Father
Both equally
Mitochondria
Explanation - The father contributes either an X or a Y chromosome, determining female (XX) or male (XY) offspring.
Correct answer is: Father
Q.4 Which process leads to the formation of gametes in sexually reproducing organisms?
Mitosis
Meiosis
Binary fission
Budding
Explanation - Meiosis reduces the chromosome number by half to form haploid gametes, ensuring genetic diversity.
Correct answer is: Meiosis
Q.5 Which type of mutation changes a single nucleotide in a DNA sequence?
Point mutation
Frameshift mutation
Chromosomal mutation
Deletion mutation
Explanation - Point mutations involve substitution of a single nucleotide, potentially altering a codon and the resulting amino acid.
Correct answer is: Point mutation
Q.6 The Hardy-Weinberg principle is used to:
Predict evolutionary trends
Calculate allele frequencies in a population
Explain speciation
Study DNA replication
Explanation - The Hardy-Weinberg equilibrium provides a mathematical model to calculate allele and genotype frequencies in a population under ideal conditions.
Correct answer is: Calculate allele frequencies in a population
Q.7 Which of the following is an example of a vestigial structure?
Human appendix
Human heart
Human lungs
Human brain
Explanation - The appendix is considered vestigial as it has lost most of its original digestive function in humans.
Correct answer is: Human appendix
Q.8 DNA replication is called semiconservative because:
Both strands are new
Both strands are old
Each new DNA has one old and one new strand
DNA is only partially replicated
Explanation - Semiconservative replication means each daughter DNA molecule retains one original strand and synthesizes one new complementary strand.
Correct answer is: Each new DNA has one old and one new strand
Q.9 Who proposed the theory of natural selection?
Gregor Mendel
Jean-Baptiste Lamarck
Charles Darwin
Thomas Huxley
Explanation - Charles Darwin proposed natural selection as the mechanism driving evolution in his book 'On the Origin of Species'.
Correct answer is: Charles Darwin
Q.10 What is the phenotypic ratio in a monohybrid cross of heterozygotes (Aa x Aa)?
3:1
1:2:1
9:3:3:1
2:1
Explanation - A monohybrid cross between two heterozygotes (Aa x Aa) gives a phenotypic ratio of 3 dominant : 1 recessive.
Correct answer is: 3:1
Q.11 Which evolutionary mechanism decreases genetic variation in a population?
Mutation
Gene flow
Genetic drift
Recombination
Explanation - Genetic drift, especially in small populations, randomly alters allele frequencies, often reducing genetic variation.
Correct answer is: Genetic drift
Q.12 Which organelle contains its own DNA and is maternally inherited?
Nucleus
Mitochondria
Ribosome
Golgi apparatus
Explanation - Mitochondria have their own DNA (mtDNA) and are inherited from the mother through the egg cytoplasm.
Correct answer is: Mitochondria
Q.13 Which cross is used to determine the genotype of an individual showing a dominant phenotype?
Dihybrid cross
Test cross
Back cross
Reciprocal cross
Explanation - A test cross involves crossing the individual with a homozygous recessive to determine if it is homozygous dominant or heterozygous.
Correct answer is: Test cross
Q.14 The theory that acquired traits can be inherited was proposed by:
Charles Darwin
Jean-Baptiste Lamarck
Gregor Mendel
Alfred Wallace
Explanation - Lamarck proposed that traits acquired during an organism's lifetime can be passed to offspring, which is largely discredited now.
Correct answer is: Jean-Baptiste Lamarck
Q.15 Which type of selection favors intermediate phenotypes and reduces extremes?
Directional selection
Disruptive selection
Stabilizing selection
Sexual selection
Explanation - Stabilizing selection favors the average phenotype and reduces variation by selecting against extreme forms.
Correct answer is: Stabilizing selection
Q.16 Which term describes different forms of a gene at the same locus?
Alleles
Chromosomes
Genomes
Exons
Explanation - Alleles are alternative versions of a gene found at the same locus on homologous chromosomes.
Correct answer is: Alleles
Q.17 The ABO blood group system in humans is an example of:
Codominance
Incomplete dominance
Polygenic inheritance
Sex-linked inheritance
Explanation - In the ABO system, both A and B alleles are expressed equally in AB blood type, demonstrating codominance.
Correct answer is: Codominance
Q.18 Which term describes a sudden heritable change in the DNA sequence?
Mutation
Crossing over
Recombination
Transcription
Explanation - Mutation is a sudden and heritable change in the DNA sequence that can affect phenotype and evolution.
Correct answer is: Mutation
Q.19 Which scientist is credited with discovering the double-helix structure of DNA?
Gregor Mendel
James Watson & Francis Crick
Rosalind Franklin
Thomas Hunt Morgan
Explanation - Watson and Crick, with critical data from Rosalind Franklin, proposed the double-helix structure of DNA in 1953.
Correct answer is: James Watson & Francis Crick
Q.20 What is the evolutionary significance of homologous structures?
Indicates common ancestry
Indicates adaptation to similar environments
Indicates vestigial function
Indicates random mutation
Explanation - Homologous structures have similar anatomical features due to shared ancestry, even if their functions differ.
Correct answer is: Indicates common ancestry
Q.21 Which process increases genetic variation during meiosis?
Independent assortment
Binary fission
Mitosis
Budding
Explanation - Independent assortment of chromosomes during meiosis results in new combinations of alleles, increasing genetic diversity.
Correct answer is: Independent assortment
Q.22 Which type of selection favors one extreme phenotype over others?
Directional selection
Stabilizing selection
Disruptive selection
Balancing selection
Explanation - Directional selection favors individuals with one extreme of a trait, causing a shift in the population's phenotype over time.
Correct answer is: Directional selection
Q.23 Which scientist is known for experiments with fruit flies that demonstrated sex-linked inheritance?
Gregor Mendel
Thomas Hunt Morgan
James Watson
Charles Darwin
Explanation - Morgan's experiments with Drosophila melanogaster showed that some traits are linked to sex chromosomes.
Correct answer is: Thomas Hunt Morgan
Q.24 What is the role of crossing over during meiosis?
To produce identical gametes
To exchange genetic material between homologous chromosomes
To duplicate DNA
To form zygotes
Explanation - Crossing over allows the exchange of genetic material between homologous chromosomes, increasing genetic variation in gametes.
Correct answer is: To exchange genetic material between homologous chromosomes