Start learning →

Bihar Board Class 12 (Science) Genetics and Evolution — practice questions — page 2

Explore 116 free Genetics and Evolution questions in Bihar Board Class 12 (Science) Biology. Open each question or exercise to read its content, reference answers and available explanation.

Practise Genetics and Evolution with Quill →

Genetics and Evolution questions and exercises with answers

Showing questions 31–60 of 116.

In a DIHYBRID cross of YyRr × YyRr, the F2 phenotypic ratio is:Read the answer and worked solution →In the human ABO blood group system, a person with blood group AB has the genotype:Read the answer and worked solution →Sickle cell anaemia is caused by:Read the answer and worked solution →Down syndrome is most commonly caused by:Read the answer and worked solution →Haemophilia and colour blindness are MORE COMMON in MALES than females because they are:Read the answer and worked solution →In DNA, Adenine (A) pairs with Thymine (T) via:Read the answer and worked solution →The Hershey-Chase experiment (1952) proved that:Read the answer and worked solution →The Central Dogma of molecular biology states that genetic information flows:Read the answer and worked solution →Okazaki fragments are produced during DNA replication on which strand?Read the answer and worked solution →The START codon in eukaryotic mRNA translation is:Read the answer and worked solution →Translation of mRNA into protein occurs on which cellular structure?Read the answer and worked solution →The Lac Operon in E. coli is INDUCED (turned ON) by the presence of:Read the answer and worked solution →The Human Genome Project (HGP) ran from 1990 to:Read the answer and worked solution →The Miller-Urey experiment (1953) demonstrated that:Read the answer and worked solution →Charles Darwin's mechanism of evolution is best described as:Read the answer and worked solution →The Hardy-Weinberg principle's equation for genotype frequencies is:Read the answer and worked solution →The wings of insects and the wings of birds are best described as:Read the answer and worked solution →The human APPENDIX is a classic example of a:Read the answer and worked solution →The shift in peppered moth (Biston betularia) colour during the Industrial Revolution is an example of:Read the answer and worked solution →The 14 species of finches that Darwin observed on the Galapagos Islands are a classic example of:Read the answer and worked solution →Genetic drift is STRONGEST in which type of population?Read the answer and worked solution →Homo sapiens (modern humans) first evolved in:Read the answer and worked solution →During transcription, the enzyme that synthesises mRNA from DNA is:Read the answer and worked solution →DNA or RNA?Read the answer and worked solution →Order the flow of genetic informationRead the answer and worked solution →Naming the processesRead the answer and worked solution →Dominant or recessive?Read the answer and worked solution →Genotype and phenotypeRead the answer and worked solution →A cross between true-breeding red (RR) and true-breeding white (rr) snapdragons gives pink F₁ plants. This pattern is best described asRead the answer and worked solution →Morgan's discovery of linkage in Drosophila showed thatRead the answer and worked solution →

Worked practice questions

In a DIHYBRID cross of YyRr × YyRr, the F2 phenotypic ratio is:

  1. $9:3:3:1$
  2. $3:1$
  3. $1:1:1:1$
  4. $1:2:1$
Show answer and solution

Correct answer: A. $9:3:3:1$

Mendel's Law of Independent Assortment: dihybrid F2 phenotypic ratio = 9:3:3:1. 9 dominant-both : 3 dominant-1 recessive-2 : 3 recessive-1 dominant-2 : 1 recessive-both.

Open this question →

In the human ABO blood group system, a person with blood group AB has the genotype:

  1. IA IA only (homozygous)
  2. ii only (homozygous recessive)
  3. IB IB only (homozygous)
  4. IA IB (codominance)
Show answer and solution

Correct answer: D. IA IB (codominance)

**ABO is CODOMINANT:** IA + IB both express in AB phenotype (both A and B antigens on RBCs). IA IA = A; IB IB = B; ii = O; IA IB = AB.

Open this question →

Sickle cell anaemia is caused by:

  1. A point mutation in the β-globin gene
  2. An extra chromosome 21 (trisomy 21)
  3. An extra X chromosome in males
  4. A deletion of the Y chromosome in males
Show answer and solution

Correct answer: A. A point mutation in the β-globin gene

Sickle cell anaemia = point mutation in the β-globin gene (GAG to GTG, glutamic acid to valine). HbS replaces HbA, causes RBCs to sickle in low oxygen. Autosomal recessive.

Open this question →

How to practise

  1. Choose a Genetics and Evolution question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

Put it into practice

Continue with Genetics and Evolution practice for Bihar Board Class 12 (Science). Read explanations as you go. No signup form needed to start.

Practise Genetics and Evolution →

More Biology topics

Reproduction in Organisms & PlantsBiotechnology and ApplicationsBiology in Human Welfare & HealthSexual Reproduction in Flowering PlantsMolecular Basis of InheritancePrinciples of Inheritance and VariationHuman Health and DiseaseEvolution