Leaving Cert Biology – Genetics Practice Test

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• What is the function of a promoter region?
• Which allele is expressed only when present in two copies and can be masked by a dominant allele?
• What is recombinant DNA and give an example?
• In a monohybrid cross between a homozygous tall plant (TT) and a homozygous short plant (tt), what fraction of offspring are tall?
• What is the main purpose of DNA profiling?
• What is the temperature and time used to denature enzymes during the kiwi DNA isolation process?
• In X-linked recessive inheritance, if the father is affected and the mother is unaffected, which offspring are affected?
• Which statement about the Y chromosome is true in humans?
• Genes present on the X chromosome are known as what?
• Migration by seeds or pollen between populations is an example of gene flow.
• What is a plasmid and how is it used in genetic engineering?
• Which statement about mitosis and meiosis is accurate?
• Explain the concept of gene regulation and how cells differentiate despite having the same genome.
• What information can a karyotype reveal?
• What is the function of DNA polymerase during DNA replication?
• Gene flow between populations tends to do which of the following regarding differences between populations?
• How does crossing over during meiosis contribute to genetic variation?
• In a cross between color-blind man (XbY) and carrier woman (XBXb), what is the probability that their son will be color blind?
• Mendel's Law of Independent Assortment states that:
• What is the diploid cell produced by the fusion of two gametes called?
• In DNA profiling, what comes after fragment separation by size via gel electrophoresis?
• What is the DNA base-pairing rule?
• What is testing a fetus for a genetic disorder called?
• What term describes a group of organisms capable of interbreeding to produce fertile offspring?
• A genetic cross involving two traits is called a
• What is the role of mutation in evolution?
• Long-term consequence of ongoing gene flow across a species' range?
• Identical alleles for a trait are called
• The allele expressed in the heterozygous condition that masks the recessive allele is called
• Which statement correctly distinguishes autosomes from sex chromosomes in humans?
• Which genotype corresponds to blood type A?
• What is the function of tRNA anticodons?
• What is the purpose of the selection marker in a plasmid vector?
• Migration into a population most directly results in which outcome?
• Chromosomes that have a role in determining the sex of an individual
• What is true about homologous chromosomes?
• X-linked recessive traits are more common in males. How can a carrier mother affect offspring?
• DNA replication occurs during which phase of the cell cycle?
• What does homozygous mean?
• If two genes are located on the same chromosome and very close together, their inheritance tends to be
• Why are sex-linked traits commonly passed from carrier mothers to their sons?
• The observable characteristics of an organism are called its
• Explain why independent assortment may not occur for genes that are close together on the same chromosome and how recombination frequency is used.
• Which step in DNA profiling involves analysing and comparing the pattern of bands?
• What does heterozygous mean?
• During the kiwi DNA isolation procedure, what is the purpose of placing the mixture in an ice bath after heating?
• How does selective advantage influence allele frequencies?
• Migration reduces genetic differences between populations primarily by:
• Aneuploidy refers to
• In autosomal recessive inheritance, if two unaffected parents have an affected child, what does this indicate about their genotypes?
• Which term describes the passing of traits from parent to offspring?
• What is the function of the plasmid origin of replication?
• Different alleles for a trait are called
• When neither allele masks the expression of the other
• Which base pairs with adenine in DNA?
• What is STR analysis and why is PCR important for DNA profiling?
• Define exon and intron and their roles in gene expression.
• Which term describes a three-base sequence in DNA that codes for an amino acid?
• For the cross Tt x tt, what is the probability that an offspring is tall?
• What is a mutation and how do point mutations differ from chromosomal mutations?
• What is a gene?
• Which chromosome does not determine the sex of an organism?
• What is gene therapy and give a basic example of its concept?
• Non-nuclear DNA (examples) include
• Which term describes the physical carrier of genes located in the nucleus?
• If a population receives a large influx of migrants from genetically diverse sources, which outcome is most likely?
• Which enzyme seals Okazaki fragments on the lagging strand?
• The way in which genetic information in a gene is decided in the cell and used to make a protein is called
• What does PCR stand for?
• Gene flow refers to the movement of which between populations?
• What is a pedigree in genetics?
• In humans, which chromosome constitution corresponds to a female?
• How do mutations in tumour suppressor genes differ from oncogenes in their effect on cancer development?
• What is the difference between transcription in prokaryotes and eukaryotes?
• Where does translation occur?
• The passing of traits from one generation to the next using genes is known as
• How does meiosis contribute to genetic variation?
• Which of the following sequences correctly lists the genetic engineering steps?
• What is a plasmid and how is it used in gene cloning?
• Which term describes alternative forms of the same gene?
• Which is the final step in the described kiwi DNA isolation protocol?
• A diagram showing the genetic history of a group of related individuals is called a
• Which genotype corresponds to blood type AB?
• What is a plasmid vector and how is it used in gene cloning?
• Which of the following is an application of DNA profiling?
• Which of the following sequences lists the steps of genetic engineering in the correct order?
• What is genetic drift and how can it affect allele frequencies in small populations?
• Which of the following is a chromosomal abnormality?
• What is the difference between sticky ends and blunt ends produced by restriction enzymes?
• Which statement best describes gene flow's effect on genetic variation within a population over time?
• In DNA replication, in which direction does DNA polymerase add nucleotides?
• Which genotype represents a typical human female?
• During which phase of the cell cycle does DNA replication take place?
• In codominance, what phenotype is shown by a heterozygote for blood type A and B?
• Cells containing two sets of chromosomes are called
• What is an allele?
• Which statement best describes non-nuclear DNA?
• Distinguish genotype frequency from phenotype frequency with a simple example.
• How many steps are listed in the genetic engineering process described, including isolation and expression?
• What is a locus?
• What is a typical example of a selectable marker used in plasmids?
• What is the difference between exons and introns?
• List some ethical considerations associated with GM foods.
• In ABO system, which concept explains AB phenotype in heterozygotes?
• Gene flow can counteract the effects of genetic drift in small populations by:
• Which processes are involved in the central dogma?
• What is the genotype for blood type O?
• During DNA replication, which enzyme lays down RNA primers?
• Haploid cells describe which statement?
• What is polymerase chain reaction (PCR) and why is it useful in genetics?
• Restriction enzymes are used in genetic engineering to cut DNA at specific sequences, producing ends that can be joined.
• A trait appears in siblings but not in the parents for two generations; which mode of inheritance is most likely?
• Which components make up a DNA nucleotide?
• Which organelles contain genetic material separate from the nucleus?
• A dihybrid cross demonstrates independent assortment by showing
• Where does transcription occur in eukaryotic cells?
• Hardy-Weinberg equilibrium genotype frequencies expression.
• Which term describes the set of instructions in DNA for building a protein?
• In DNA, a group of three bases that specifies an amino acid is known as a
• What is gel electrophoresis and how is it used to separate DNA fragments?
• How long is the blending step in the kiwi DNA isolation protocol?
• Define Hardy-Weinberg principle in simple terms.
• ELSI in genetics refers to
• DNA that does not code for a protein is called
• The sequence of bases in DNA that provide the instructions for a cell to form a protein is the
• Which of the following best defines a sex-linked trait?
• Which genotype produces O phenotype?
• Which statement best distinguishes somatic mutations from germline mutations?
• Which term describes the allele that masks the expression of a recessive allele in a heterozygote?
• Which tool is used to show all possible genotypes of a genetic cross?
• What is crossing over and when does it occur?
• Why are X-linked inheritance patterns more likely to affect males?
• Gene flow interacts with natural selection by:
• What term describes the orientation of the two DNA strands, which run in opposite directions?
• What is the function of restriction enzymes in genetic engineering?
• In a heterozygous genotype, both alleles are expressed equally to produce an intermediate phenotype
• Which statement best describes autosomal recessive inheritance?
• The position of a gene on a chromosome is called?
• Which statement correctly describes incomplete dominance?
• In STR analysis, what is being measured?
• What is the central dogma of molecular biology?
• Which statement summarizes Mendel's Law of Segregation?
• What is the function of the multiple cloning site in a plasmid?
• In the kiwi DNA isolation procedure, what is achieved by adding kiwi pieces to the washing liquid and salt mixture?
• In gene therapy, what is the typical aim?
• A silent mutation is
• Colour blindness and Haemophilia are examples of what type of genetic conditions?
• Why are bacteria used to produce recombinant human insulin?
• What term refers to having two identical alleles for a trait?
• Which of the following is an application of genetic engineering in animals?
• What is the function of a ribosome in translation?
• The manipulation (and alteration) of genes is called?
• What purpose does staining serve in gel electrophoresis?
• In PCR, what is the purpose of the denaturation step?
• Which of the following is an application of genetic engineering in microorganisms?
• Which enzyme synthesizes new DNA on the leading and lagging strands?
• Which enzyme seals the sugar-phosphate backbone during DNA replication?
• A person who is heterozygous for a gene is called a
• In humans, which chromosome constitution corresponds to a male?
• The ABO blood groups illustrate which genetic concept?
• What is the role of haploid cells in sexual reproduction?
• During DNA replication, which enzyme unwinds the double helix?
• What term best describes a trait controlled by genes on the sex chromosomes?
• Which of the following best describes a plasmid vector in gene cloning?
• Which chromosomes are autosomes in humans?
• What is gel electrophoresis used for in molecular biology?
• In a dihybrid cross AaBb x AaBb, what phenotype ratio is expected?
• Haploid and diploid refer to what?
• Telomerase activity is typically found in which cells?
• What is a restriction enzyme and how does it facilitate gene cloning?
• Which of the following is an example of a polygenic trait?
• Which would be a consequence of high levels of gene flow among neighboring populations?
• Which definition best captures gene flow?
• Which term is used to describe the effect where neither allele masks the other, resulting in an intermediate phenotype?
• Two carrier parents for a recessive trait have a child. What is the probability the child will be affected?
• Which statement correctly describes the sex chromosome makeup of a human male?
• What is a plasmid backbone with regard to cloning, and what components are typically required?
• How is recombinant human insulin produced using bacteria?
• Which genotype produces AB phenotype?
• Where does transcription occur and what does it produce?
• Fertilisation is defined as the fusion of the
• Which allele is an example of a dominant allele in humans?
• What is the difference between genotype and phenotype?
• Which ABO blood type demonstrates codominance in inheritance?
• What is phenotype?
• The two types of genetic screening mentioned are?
• Which statement about sex-linked traits is most accurate?
• In autosomal recessive inheritance, if two unaffected parents have an affected child, what is the probability that their other child is a carrier?
• What is PCR amplification cycle and the purpose of each step?
• Which alleles determine ABO blood groups?
• Which term describes a diploid cell produced by the fusion of two gametes?
• What happens to allele frequencies when migrants introduce new alleles into a population?
• During meiosis I, crossing over occurs to
• In the kiwi DNA isolation process, which step comes immediately after mixing washing up liquid and salt in water?
• What is a knockout gene technique and how is it used in research?
• What is PCR and what are its main steps?
• Which statement best describes independent assortment?
• The exact location of a gene on a chromosome is called?
• Which term denotes a haploid cell capable of fusion?
• How is DNA profiling used in forensic science?
• What term describes organisms that always produce offspring identical to themselves and are homozygous for a trait?
• In a cloning plasmid, what is the role of the promoter?
• Which statement describes a gene versus a genome?
• Which statement best describes the inheritance of cystic fibrosis in terms of the CFTR gene?
• Gene flow between populations can have which of the following combined effects on genetic variation?
• What is CRISPR-Cas9 and how is it used in genetics?
• Which statement correctly differentiates codominance from incomplete dominance?
• What is the structure of a DNA molecule?
• Which mutation is commonly cited as enabling adults to digest lactose?
• Germline mutation pass to offspring
• How can natural selection alter allele frequencies in a population?
• What is a gene?
• Explain the concept of transformation in bacteria.
• Which term refers to the structure made of DNA and protein that carries genetic information?
• Gene locus is defined as
• What is genotype?
• What is a selectable marker and why is it used in cloning?
• Which condition is an example of monosomy?
• Genetic screening is a diagnostic test to identify the presence or absence of changed genes.
• Cells with only one set of chromosomes are called
• What is the term for testing an adult to see if they carry a gene for a genetic disorder, and thus assess risk to their offspring?
• What is the role of telomeres in protecting chromosome ends and how are they linked to aging?
• In DNA profiling, after fragment separation, what is done with the patterns?
• Which of the following best describes a pure-breeding organism?
• A haploid cell capable of fusion is a
• Codominance means both alleles are fully expressed in the heterozygote. Which human example demonstrates codominance?
• Which statement best describes the overall effect of gene flow on population differentiation?
• What is a sex-linked trait and why are males more frequently affected?
• RNA polymerase in transcription
• Why is type O negative often called the universal donor for blood transfusions?
• In DNA profiling, what determines the length of fragments produced by restriction enzymes?
• DNA not contained in the nucleus that is passed from one generation to the next is
• A sequence of three DNA bases that codes for an amino acid is called
• Which ethical concern is specifically related to germline modification in gene therapy?
• Which statement about sex-linked inheritance is commonly observed in human families?
• Which of the following is an application of genetic engineering in plants?
• A genetic cross where one trait is being examined is called a
• In codominance, how are the alleles expressed in the phenotype? (Using ABO blood groups as an example.)
• What happens to introns during RNA processing?
• How does selective breeding differ from genetic engineering?
• What term describes the genetic makeup of an individual in terms of specific alleles?
• Which two processes contribute to genetic variation in meiosis?
• In autosomal recessive inheritance, can an affected individual have unaffected parents?
• Which term is defined as a section of DNA that causes the production of a protein?
• What is gene therapy and what are potential ethical concerns?
• In DNA profiling, which step involves separating DNA fragments by size using an electric current through a gel?
• What are homologous chromosomes?
• What term describes genes on the same chromosome that are inherited together?
• What term describes the genetic makeup of an organism?
• During gamete formation, how many alleles from each gene pair are present in a gamete?
• Meiosis yields haploid gametes.
• The physical appearance of an organism produced by genotype and environment is its
• What is a genome?
• In a monohybrid cross between Tt x Tt, what is the phenotype ratio of tall to short?
• Which statement best defines an allele?