Genetics Quizzes for Year 12 Biology: Test Your Knowledge

Question 1

Which enzyme is responsible for unwinding the DNA double helix during DNA replication?

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

Primase

Answer

Ligase

Question 2

Which nitrogenous base is NOT found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Thymine

Question 3

What is a characteristic of mutations?

Accepted Answer

They can alter the sequence of nucleotides in DNA.

Answer

They are always harmful.

Answer

They are always inherited.

Answer

They are always caused by radiation.

Question 4

Which component is not present in a DNA nucleotide?

Accepted Answer

Ribose

Answer

Deoxyribose

Answer

Adenine

Answer

Phosphate

Question 5

Which of the following statements about DNA replication is correct?

Accepted Answer

DNA replication occurs in the nucleus of the cell.

Accepted Answer

DNA replication is catalyzed by the enzyme DNA polymerase.

Accepted Answer

DNA replication results in the production of two identical daughter molecules.

Answer

DNA replication is a continuous process.

Question 6

In DNA, which nitrogenous base forms a pair with adenine through two hydrogen bonds?

Accepted Answer

Thymine

Answer

Guanine

Answer

Uracil

Answer

Cytosine

Question 7

Which of the following nitrogenous bases is NOT found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 8

Which nitrogenous base is found exclusively in RNA but not in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 9

Which component is NOT found in a nucleotide?

Accepted Answer

Amino acid

Answer

Ribose or deoxyribose

Answer

Phosphate group

Answer

Nitrogenous base

Question 10

Which nucleotide sequence in DNA determines the specific amino acid sequence of a polypeptide?

Accepted Answer

Codon

Answer

Exon

Answer

Intron

Answer

Anticodon

Question 11

During protein synthesis, which process converts the genetic code in mRNA into a chain of amino acids?

Accepted Answer

Translation

Answer

Replication

Answer

Transcription

Answer

Mutation

Question 12

Which sequence accurately represents the steps involved in protein synthesis?

Accepted Answer

Transcription, Translation, Post-Translational Modification

Answer

Replication, Transcription, Translation

Answer

Translation, Transcription, Post-Translational Modification

Answer

Post-Translational Modification, Replication, Transcription

Question 13

Which nitrogenous base is unique to RNA and not found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Thymine

Answer

Cytosine

Question 14

In DNA replication, what is the primary function of DNA polymerase?

Accepted Answer

Synthesizing new DNA strands

Answer

Unwinding the DNA double helix

Answer

Proofreading the new DNA strands

Answer

Stabilizing the new DNA double helix

Question 15

Which nitrogenous base is NOT found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 16

Which of the following is NOT a component of a nucleotide, the basic unit of DNA?

Accepted Answer

Amino acid

Answer

Deoxyribose or ribose

Answer

Phosphate

Answer

Nitrogenous base

Question 17

Which of the following processes is not directly involved in protein synthesis?

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Modification

Question 18

Which nitrogenous base is found in RNA but not in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Thymine

Answer

Guanine

Question 19

Which nucleotide change occurs during a deletion mutation?

Accepted Answer

Deletion of one or more nucleotides

Answer

Insertion of one or more nucleotides

Answer

Substitution of one or more nucleotides with different nucleotides

Answer

Reversal of the order of nucleotides

Question 20

What is the primary function of genes in living organisms?

Accepted Answer

Provide instructions for creating proteins

Answer

Solely determine an organism's physical traits

Answer

Store genetic information exclusively for cell division

Question 21

In Mendelian genetics, when parents with different traits have offspring with a phenotype that is a blend of both parents' traits, what is this phenomenon called?

Accepted Answer

Incomplete Dominance

Answer

Dominance

Answer

Codominance

Answer

Polygenic Inheritance

Question 22

What is NOT a component of a nucleotide?

Accepted Answer

Amino acid

Answer

Deoxyribose or ribose sugar

Answer

Phosphate group

Answer

Nitrogenous base

Question 23

Which nitrogenous base is exclusive to RNA and not present in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Thymine

Answer

Cytosine

Question 24

How can a missense mutation affect the resulting protein?

Accepted Answer

It can change the protein's function.

Answer

It always makes the protein non-functional.

Answer

It only happens in parts of DNA that don't code for proteins.

Answer

It always makes the protein more stable.

Question 25

During which stage of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Answer

Metaphase I

Answer

Metaphase II

Question 26

Which of the following describes the specific base-pairing rules in DNA?

Accepted Answer

Adenine pairs with thymine, and guanine pairs with cytosine.

Answer

Adenine pairs with cytosine, and guanine pairs with thymine.

Answer

Adenine pairs with guanine, and cytosine pairs with thymine.

Answer

Uracil pairs with thymine, and cytosine pairs with guanine.

Question 27

Which nitrogenous base is found exclusively in RNA, but not in DNA?

Accepted Answer

Uracil

Answer

Adenine

Question 28

How is genetic information used in medicine? Explain its role in diagnosing and treating genetic disorders, as well as its contributions to personalized medicine and gene therapy.

Accepted Answer

Genetic information helps diagnose genetic disorders through techniques like DNA sequencing and genetic testing.

Accepted Answer

Personalized medicine uses genetic information to tailor treatments based on individual genetic profiles, improving effectiveness and reducing side effects.

Accepted Answer

Gene therapy involves modifying genetic material to treat or prevent genetic disorders, offering new therapeutic options.

Answer

Genetic information is not relevant in medical applications.

Question 29

How do introns and exons contribute to gene expression and protein synthesis?

Accepted Answer

Introns are non-coding regions removed during mRNA processing, while exons are coding regions translated into protein.

Answer

Exons are non-coding regions removed during mRNA processing, while introns are coding regions translated into protein.

Answer

Introns and exons are both coding regions translated into protein, but introns are removed during RNA splicing.

Answer

Introns and exons are both non-coding regions not translated into protein.

Question 30

How has the application of genetics significantly impacted forensic science in criminal investigations?

Accepted Answer

Enabled highly accurate identification of individuals through DNA analysis

Answer

Eliminated the necessity for other evidence forms

Answer

Guaranteed definitive proof of guilt or innocence

Answer

Completely eliminated human bias and prejudice

Question 31

What is genetic diversity, and why is it crucial for the survival and adaptability of species?

Accepted Answer

Genetic diversity refers to the variations in genetic traits within a population, making it more resilient and adaptable to different environments.

Answer

Genetic diversity is primarily driven by mutations that accumulate in populations over time.

Answer

Genetic diversity has no significant impact on a species' ability to adapt to environmental changes.

Answer

Genetic diversity is only important in species with large populations, as it allows for a wider range of genetic variation.

Question 32

Which of the following is **NOT** a fundamental principle of inheritance proposed by Gregor Mendel?

Accepted Answer

Law of Incomplete Dominance

Answer

Law of Segregation

Answer

Law of Independent Assortment

Answer

Law of Dominance

Question 33

A homozygous individual carries two identical alleles for a particular gene. What is the probability that they will pass on a dominant allele to their offspring?

Accepted Answer

100%

Answer

0%

Answer

25%

Answer

50%

Question 34

Which of the following is an example of a quantitative trait?

Accepted Answer

Height

Answer

Eye colour

Answer

Blood type

Answer

Sex

Question 35

Which of the following is the fundamental unit of heredity that carries genetic information?

Accepted Answer

Gene

Answer

Chromosome

Answer

Allele

Answer

Nucleotide

Question 36

In a Mendelian monohybrid cross, what is the probability of obtaining a homozygous recessive genotype in the offspring of parents who are both heterozygous?

Accepted Answer

0.25

Answer

0.50

Answer

0.75

Answer

1.00

Question 37

What is the distinction between a genotype and a phenotype?

Accepted Answer

Genotype refers to the genetic makeup, while phenotype refers to the observable characteristics.

Answer

Genotype refers to the observable characteristics, while phenotype refers to the genetic makeup.

Answer

Genotype and phenotype are synonymous terms.

Answer

Genotype refers to the environment, while phenotype refers to the genetic makeup.

Question 38

Which of the following is an example of a trait that is inherited in a sex-linked manner?

Accepted Answer

Haemophilia

Answer

Cystic fibrosis

Answer

Huntington's disease

Answer

Down syndrome

Question 39

What term describes an organism's observable characteristics?

Accepted Answer

Phenotype

Answer

Genotype

Answer

Allele

Answer

Chromosome

Question 40

What term describes a genetic disorder caused by a mutation in a single gene?

Accepted Answer

Monogenic disorder

Answer

Chromosomal disorder

Answer

Polygenic disorder

Answer

Multifactorial disorder

Question 41

Which characteristic is associated with a genetic disorder caused by a dominant allele?

Accepted Answer

Expressed in individuals carrying the allele

Answer

Expressed only if both alleles are dominant

Answer

Less common than recessive disorders

Answer

Typically milder than recessive disorders

Question 42

What type of mutation alters the protein structure?

Accepted Answer

Missense mutation

Answer

Silent mutation

Answer

Frameshift mutation

Answer

Nonsense mutation

Question 43

What is the primary use of a Punnett square?

Accepted Answer

Predicting offspring genotypes

Answer

Determining individual phenotypes

Answer

Identifying individual alleles

Answer

Diagnosing genetic disorders

Question 44

What is the process called that involves the exchange of genetic material between homologous chromosomes during meiosis?

Accepted Answer

Crossing over

Answer

Independent assortment

Answer

Mutation

Answer

Recombination

Question 45

The fundamental unit of heredity is the:

Accepted Answer

Gene

Answer

Chromosome

Answer

Nucleus

Answer

Cell

Question 46

In a cross involving a heterozygous parent, the genotype is represented as:

Accepted Answer

Hh

Answer

HH

Answer

hh

Answer

HhHh

Question 47

Which genetic disorder is caused by a dominant allele?

Accepted Answer

Huntington's disease

Answer

Cystic fibrosis

Answer

Sickle cell anaemia

Answer

Tay-Sachs disease

Question 48

The probability of inheriting a recessive allele from a heterozygous parent is:

Accepted Answer

0.25

Answer

0.5

Answer

0.75

Answer

1

Question 49

The technique used to separate DNA fragments based on size is:

Accepted Answer

Gel electrophoresis

Answer

PCR

Answer

DNA sequencing

Answer

DNA fingerprinting

Question 50

Which of the following is NOT a principle of Mendelian genetics?

Accepted Answer

The principle of gene linkage

Answer

The principle of segregation

Answer

The principle of independent assortment

Answer

The principle of dominance

Question 51

In a population of pea plants, 25% of the offspring exhibit a recessive phenotype. What is the frequency of the recessive allele in this population?

Accepted Answer

0.25

Answer

0.5

Answer

0.75

Answer

1.0

Question 52

Which of the following is a characteristic of codominance?

Accepted Answer

Both alleles are fully expressed in the heterozygous genotype

Answer

One allele is dominant over the other in the heterozygous genotype

Answer

The heterozygous genotype has an intermediate phenotype between the two homozygous genotypes

Answer

The heterozygous genotype has a unique phenotype that is different from both homozygous genotypes

Question 53

What type of inheritance pattern is observed when the heterozygous genotype has an intermediate phenotype between the two homozygous genotypes?

Accepted Answer

Incomplete dominance

Answer

Codominance

Answer

Multiple alleles

Answer

Pleiotropy

Question 54

Natural selection acts on:

Accepted Answer

Individuals with advantageous traits

Answer

Individuals with disadvantageous traits

Answer

All individuals within a population

Answer

Only the strongest individuals within a population

Question 55

What is the primary role of genetic counseling?

Accepted Answer

Providing information and support to individuals and families facing genetic risks

Answer

Identifying and diagnosing genetic disorders

Answer

Promoting eugenics and selective breeding

Question 56

Which of the following is NOT a fundamental principle of Mendelian genetics?

Accepted Answer

Continuous variation

Answer

Segregation of alleles

Answer

Independent assortment

Answer

Incomplete dominance

Question 57

Which of the following is an example of a sex-linked recessive trait?

Accepted Answer

Color blindness

Answer

Huntington's disease

Answer

Cystic fibrosis

Answer

Down syndrome

Question 58

What is the primary role of genetic counselors?

Accepted Answer

Providing information about inheritance patterns and genetic risks

Answer

Offering emotional support and guidance

Answer

Developing treatment plans for genetic disorders

Answer

Conducting laboratory tests to diagnose genetic conditions

Question 59

Which of the following is NOT a driving force behind genetic diversity?

Accepted Answer

Artificial selection

Answer

Mutation

Answer

Gene flow

Answer

Genetic drift

Question 60

Which of the following is the fundamental unit of heredity, carrying the genetic information that is passed on from parents to offspring?

Accepted Answer

Gene

Answer

Allele

Answer

Chromosome

Answer

Nucleotide

Question 61

In the context of genetics, what term refers to the observable characteristics or traits of an organism, resulting from the interaction of its genotype with the environment?

Accepted Answer

Phenotype

Answer

Karyotype

Answer

Genome

Answer

Genotype

Question 62

What term describes a heritable change in the DNA sequence, which can introduce new traits or alter existing ones?

Accepted Answer

Mutation

Answer

Transduction

Answer

Epigenetics

Answer

Recombination

Question 63

Which of the following is an example of a trait that is inherited in a pattern linked to the sex chromosomes?

Accepted Answer

Colorblindness

Answer

Down syndrome

Answer

Cystic fibrosis

Answer

Huntington's disease

Question 64

Which type of genetic disorder is caused by an abnormal number of chromosomes in an individual's cells?

Accepted Answer

Aneuploidy

Answer

Sickle cell anemia

Answer

Hemophilia

Answer

Cystic fibrosis