Genetics
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
DNA Structure and Function
SubtopicDNA Structure and Function under Genetics for Grade 9 IB.
Preview questions (no answers)
- 1.
What is the name of the process where the information in mRNA is used to build a chain of amino acids (a protein)?
A.Transcription
B.Translation
C.Replication
D.Respiration
- 2.
In DNA profiling, fragments of DNA are separated by size using an electric field in a process called:
A.Centrifugation
B.Gel electrophoresis
C.Distillation
D.Titration
- 3.
What is the term for an organism that contains DNA from another species introduced through genetic engineering?
A.Hybrid
B.Transgenic
C.Mutant
D.Homozygous
- 4.
Which molecule carries the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm?
A.mRNA
B.tRNA
C.ATP
D.DNA polymerase
- 5.
What is the main goal of the Human Genome Project?
A.To clone a human being
B.To determine the sequence of all the base pairs in human DNA
C.To eliminate all genetic diseases in one generation
D.To create new species of humans using genetic engineering
- 6.
Which base is found in RNA but NOT in DNA?
A.Adenine
B.Guanine
C.Uracil
D.Thymine
- 7.
What occurs during the process of 'translation'?
A.DNA is copied into a new DNA molecule
B.DNA is used as a template to make mRNA
C.mRNA is used as a template to build a polypeptide
D.RNA is used to synthesize a new DNA strand
- 8.
A segment of double-stranded DNA has a total length of . Given that the distance between adjacent base pairs is exactly and that Adenine () constitutes of the total nitrogenous bases, calculate the total number of hydrogen bonds holding the two strands together in this segment.
A.B.C.D. - 9.
What is the role of 'chiasmata' in increasing genetic variation?
A.They are the sites where sister chromatids are held together during mitosis.
B.They are the physical locations where non-sister chromatids exchange genetic material.
C.They are the proteins that pull chromosomes toward the poles during anaphase.
D.They represent the mutations caused by UV radiation during S-phase.
- 10.
Which of the following statements about DNA methylation is true?
A.It typically increases the rate of transcription for the affected gene.
B.It involves the addition of a methyl group to the ribose sugar.
C.It is often associated with gene silencing and reduced expression.
D.It is a permanent change to the DNA sequence that cannot be reversed.
Download the worksheet for Genetics - DNA Structure and Function to practice offline. It includes additional chapter-level practice questions.
Chromosomes and Genes
SubtopicChromosomes and Genes under Genetics for Grade 9 IB.
Preview questions (no answers)
- 1.
Which part of the cell acts as the control center and contains the chromosomes?
A.Mitochondria
B.Ribosome
C.Nucleus
D.Vacuole
- 2.
What is the primary reason why offspring look similar to, but not exactly like, their parents?
A.They inherit all genes from only one parent
B.They inherit a unique combination of genes from both parents
C.DNA changes completely every generation
D.Genes are not involved in physical appearance
- 3.
Which of the following would result in a male offspring in humans?
A.An X egg fertilized by an X sperm
B.A Y egg fertilized by an X sperm
C.An X egg fertilized by a Y sperm
D.A Y egg fertilized by a Y sperm
- 4.
What links the sugar of one nucleotide to the phosphate of the next nucleotide in a DNA strand?
A.Hydrogen bonds
B.Covalent bonds
C.Ionic bonds
D.Peptide bonds
- 5.
A human cell contains 46 chromosomes, yet it carries the instructions for approximately 20,000 different genes. Based on the diagram of a single chromosome, which statement best explains how these genes are organized?
A.Each chromosome consists of a long DNA molecule that contains many different genes at specific locations.
B.Every gene is stored on its own separate chromosome to prevent genetic interference.
C.A chromosome is composed of a single gene that repeats itself thousands of times to ensure survival.
D.Genes are found only on the sex chromosomes, while the other 44 chromosomes are empty structural units.
- 6.
What does the 'm' in mRNA stand for?
A.Modified
B.Molecular
C.Messenger
D.Mitochondrial
- 7.
Which of these traits is likely controlled by multiple genes (polygenic inheritance)?
A.Human height
B.Attached earlobes
C.Cystic fibrosis
D.Pea plant flower color
- 8.
Which of the following best describes 'polygenic inheritance'?
A.A single gene controlling multiple traits.
B.Multiple genes controlling a single trait, often resulting in continuous variation.
C.A trait that is only expressed in individuals with multiple nuclei.
D.The inheritance of genes only from the maternal side.
- 9.
In a DNA double helix, if the percentage of Adenine is 15%, what is the percentage of Guanine?
A.15%
B.35%
C.70%
D.85%
- 10.
How many autosomes are found in a normal human sperm cell?
A.22
B.23
C.44
D.46
Download the worksheet for Genetics - Chromosomes and Genes to practice offline. It includes additional chapter-level practice questions.
Mendelian Inheritance and Punnett Squares
SubtopicMendelian Inheritance and Punnett Squares under Genetics for Grade 9 IB.
Preview questions (no answers)
- 1.
Which of these genotypes is homozygous dominant?
A.B.C.D. - 2.
If a characteristic like 'inflated pod' is dominant and 'constricted pod' is recessive, what happens when a plant has one allele for each?
A.The pods will be constricted
B.The pods will be inflated
C.The pods will be half-inflated
D.The plant will not produce pods
- 3.
In a cross between and , what percentage of offspring will have the genotype ?
A.0%
B.50%
C.75%
D.100%
- 4.
What is the phenotype of an organism?
A.The genetic code it carries
B.Its physical appearance or observable traits
C.The number of chromosomes it has
D.Its ability to survive in the wild
- 5.
Which of the following best defines an allele?
A.A structure made of DNA and proteins.
B.A specific version or alternative form of a gene.
C.The physical appearance of an organism.
D.The set of all genes in a population.
- 6.
Which of the following ratios describes the genotype distribution of a cross between two heterozygous individuals ()?
A.3:1
B.1:1
C.1:2:1
D.9:3:3:1
- 7.
If a cross results in 100% heterozygous offspring, what were the genotypes of the parents?
A.B.C.D. - 8.
If an organism has the genotype , which of the following diagrams correctly represents the principle of segregation for the 'A' gene?
A.A cell dividing to produce two 'A' gametes.
B.A cell dividing to produce one 'A' and one 'a' gamete.
C.A cell dividing to produce four 'Aa' gametes.
D.A cell dividing to produce two 'A' and two 'B' gametes.
- 9.
In a cross , what is the probability of producing an offspring that is heterozygous for all three genes?
A.B.C.D. - 10.
What is the primary reason that males are more frequently affected by X-linked recessive disorders than females?
A.Males have two X chromosomes.
B.Males are hemizygous for the X chromosome.
C.The Y chromosome carries a suppressor for most X genes.
D.X-linked traits are only passed from father to son.
Download the worksheet for Genetics - Mendelian Inheritance and Punnett Squares to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
A chromosomal mutation involves changes in:
A.A single nitrogen base
B.The sugar group
C.Large segments of DNA or whole chromosomes
D.The cell's cytoplasm
- 2.
Which of these is a consequence of a mutation in the hemoglobin gene?
A.Type 1 Diabetes
B.Sickle cell anemia
C.Color blindness
D.Lactose intolerance
- 3.
If a mutation causes a change in a bird's beak shape that allows it to eat more types of seeds, this mutation is:
A.Harmful
B.Neutral
C.Advantageous
D.Silent
- 4.
How can cells sometimes prevent mutations from being permanent?
A.By drinking more water
B.Using DNA repair enzymes
C.By stopping all cell division
D.By changing their temperature
- 5.
Why is 'Down Syndrome' classified as a chromosomal mutation rather than a gene mutation?
A.It involves an extra copy of an entire chromosome (Trisomy 21)
B.It is caused by a single nucleotide substitution on chromosome 21
C.It only occurs in somatic cells, not germline cells
D.It is caused by a deletion of a single gene on the X chromosome
- 6.
If a protein usually contains a hydrophobic amino acid and a mutation replaces it with a hydrophilic one, what is the likely result?
A.The protein's primary structure will change, but the 3D shape will be identical
B.The protein's tertiary structure (folding) will likely be disrupted
C.The protein will immediately turn into an mRNA strand
D.There will be no change because amino acids all have the same properties
- 7.
Which biological process relies on controlled mutations and genetic recombination to generate antibody diversity in the immune system?
A.Somatic hypermutation
B.Apoptosis
C.Binary fission
D.DNA denaturation
- 8.
Which of the following would be the most likely result of a mutation that inactivates the protein?
A.The cell will stop dividing immediately.
B.The cell will be unable to repair DNA damage but will continue to divide.
C.The cell will start producing extra insulin.
D.The cell will convert from a eukaryotic to a prokaryotic state.
- 9.
A mutation that changes a codon from (Glycine) to (Arginine) is a missense mutation. Glycine is non-polar and very small, while Arginine is large and positively charged. This change is likely to:
A.Have no effect on the protein structure.
B.Significantly alter the protein's folding and function.
C.Increase the stability of the protein at high temperatures.
D.Prevent the ribosome from binding to the mRNA.
- 10.
During DNA replication, an extra base is accidentally added into the new strand. If the mismatch repair system fails, what will be the state of the DNA after the next round of replication?
A.One daughter DNA molecule will have an insertion mutation; the other will be normal.
B.Both daughter DNA molecules will have the insertion mutation.
C.The DNA will be destroyed by the cell.
D.The extra base will be converted into a different base.
Download the worksheet for Genetics - Genetic Mutations to practice offline. It includes additional chapter-level practice questions.
Molecular Biology and Biotechnologies
SubtopicMolecular Biology and Biotechnologies under Genetics for Grade 9 IB.
Preview questions (no answers)
- 1.
In genetic terms, what is the 'genotype'?
A.The physical appearance of an organism
B.The genetic makeup or set of alleles
C.The environment the organism lives in
D.The list of proteins in a cell
- 2.
Which cells in the human body do NOT contain a nucleus (and therefore no nuclear DNA)?
A.Skin cells
B.Nerve cells
C.Mature red blood cells
D.Muscle cells
- 3.
Why is DNA called the 'blueprint' of life?
A.Because it is blue in color
B.Because it contains the instructions for building an organism
C.Because it is found in every liquid in the body
D.Because it can be folded like paper
- 4.
Which of the following is NOT a nitrogenous base found in DNA?
A.Adenine
B.Thymine
C.Uracil
D.Guanine
- 5.
Which of the following describes the correct base-pairing in DNA?
A.A pairs with C, G pairs with T
B.A pairs with G, C pairs with T
C.A pairs with T, C pairs with G
D.A pairs with U, C pairs with G
- 6.
The structure of the DNA molecule was primarily discovered by Watson and Crick, but they relied heavily on X-ray diffraction data produced by:
A.Charles Darwin
B.Gregor Mendel
C.Rosalind Franklin
D.Louis Pasteur
- 7.
In biotechnology, 'DNA ligase' is often used after which other tool?
A.PCR machine
B.Restriction enzymes
C.Centrifuge
D.DNA sequencer
- 8.
If a researcher wanted to determine the exact order of nucleotides in a specific gene, which biotechnology technique would they use?
A.Polymerase Chain Reaction (PCR)
B.Gel Electrophoresis
C.DNA Sequencing
D.Bacterial Transformation
- 9.
Which of the following correctly describes the function of 'Exonucleases' in DNA repair?
A.They add new bases to the end of the DNA strand
B.They remove mismatched or damaged nucleotides from the end of a DNA strand
C.They link together the Okazaki fragments on the lagging strand
D.They unwind the DNA double helix at the start of a gene
- 10.
What is the biological significance of the 'anti-parallel' arrangement of DNA strands?
A.It allows for the formation of hydrogen bonds between the bases
B.It ensures that the two strands are identical to each other
C.It allows enzymes like DNA polymerase to work in opposite directions on the two strands
D.It prevents the DNA from ever being unzipped
Download the worksheet for Genetics - Molecular Biology and Biotechnologies to practice offline. It includes additional chapter-level practice questions.