HL Paper 2
RNA molecules play numerous roles in gene expression and so contribute to variation.
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
Explain transcription.
Distinguish between continuous and discrete variation, using examples.
Cells go through a repeating cycle of events in growth regions such as plant root tips and animal embryos. Outline this cell cycle.
Draw a labelled diagram of the formation of a chiasma by crossing over.
Explain the control of gene expression in eukaryotes.
DNA forms chromosomes, but much of eukaryote DNA is non-coding.
[Source: Pixabay.]
People can be analysed genetically for risks of specific diseases before they actually develop. One of these is type I diabetes.
Describe the structure of nucleosomes.
Explain how the two strands of the DNA double helix are held together.
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
Explain what happens in a person when they develop type I diabetes.
State how type I diabetes should be treated to avoid harmful health consequences of the condition.
DNA methylation has a critical role in gene regulation by affecting transcription. Samples were taken from two colon cancer tumours (T1 and T2) and two normal colon samples (N1 and N2). A particular gene was implicated as a possible cause of cancer. The promoter of this gene was cloned (A–J). The data show the DNA methylation patterns from these samples. The numbers (32–269) represent different markers in the promoter.
[Source: Philipp Schatz, Dimo Dietrich & Matthias Schuster. Rapid analysis of CpG methylation patterns using RNase T1
cleavage and MALDI-TOF. Nucleic Acids Research (2004) 32 (21): e167, doi:10.1093/nar/gnh165.
Reproduced by permission of Oxford University Press]
Identify the stage of mitosis labelled X in the image, giving a reason.
[Source: Copyright 2002, The Trustees of Indiana University]
Outline what is indicated by the mitotic index of tissue taken from a tumour.
DNA has regions that do not code for proteins. State two functions of these regions.
1.
2.
Outline the difference in methylation pattern between tumorous and normal tissue samples.
Suggest a way methylation may affect tumour cell genes.
Label a peptide bond in the diagram of a polypeptide.
Outline the primary structure of proteins.
Identify two hydrolysis reactions that occur in the small intestine.
Draw molecular diagrams to show the condensation reaction between two amino acids to form a dipeptide.
Outline the roles of the different binding sites for tRNA on ribosomes during translation.
Explain the production of antibodies.
Sickle cell anemia is due to a single base substitution in DNA. Using the diagram, outline how this translates into the production of an abnormal hemoglobin molecule by completing the spaces labelled I, II and III.
DNA codes for the amino acid sequence of polypeptides. List two other functions of DNA.
Distinguish between the purpose of free and bound ribosomes.
Angiospermophyta are vascular flowering plants.
Describe the transport of organic compounds in vascular plants.
The flowers of angiospermophyta are used for sexual reproduction. Outline three processes required for successful reproduction of angiospermophyta.
Growth in living organisms includes replication of DNA. Explain DNA replication.
Proteins are an important group of chemicals found in all living organisms.
Draw a molecular diagram to show the formation of a peptide bond.
Outline how proteins are digested and the products of protein digestion absorbed in humans.
Explain how polypeptides are produced by the process of translation.
Nucleosomes help to regulate transcription in eukaryotes.
State the components of a nucleosome.
Nucleosomes help to regulate transcription in eukaryotes.
State a chemical modification of a nucleosome that could impact gene expression.
Outline the roles of helicase and ligase in DNA replication.
Explain how natural selection can lead to speciation.
Outline the features of ecosystems that make them sustainable.
State one similarity and one difference between the structure of genes and short tandem repeats.
Outline the role of short tandem repeats in DNA profiling.
Draw the structure of a section of DNA showing all possible bases.
Outline the structural and genetic characteristics of eukaryotic chromosomes.
Explain how a polypeptide chain is synthesized in a eukaryotic cell.
The diagram shows alpha amylase.
Explain the secondary structure of this protein molecule.
Amylase is used in human digestion.
State two sites of production of amylase.
Amylase is used in human digestion.
State the function of amylase.
Explain how enzymes catalyse chemical reactions.
Nitrogen is part of many important substances in living organisms.
Draw labelled diagrams to show a condensation reaction between two amino acids.
Nitrogen is part of many important substances in living organisms.
Distinguish between transcription and translation.
Nitrogen is part of many important substances in living organisms.
Explain how insects excrete nitrogenous wastes.
The figure shows a tripeptide.
Label one peptide bond in this molecule.
Describe the secondary structure of proteins.
Outline the action taken by the diaphragm during inhalation.
State one role of nucleosomes in eukaryotic cells.
Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
State one function for a region of DNA that does not code for proteins.
Outline the role of the A-site of ribosomes in translation.
Outline the role of tRNA activating enzymes in translation.