GN 301 Exam Review for Test #1

Course Information

• GN 301: Genetics in Human Affairs
• Exam Review for Test #1

Exam Day Information

• Exams are required at DELTA Testing Services or approved remote proctor
• Appointment at DELTA is required, schedule at least 4 hours in advance
• Exam is online on Moodle
• Calculator may be needed, bring one
• One attempt is allowed
• Exam time limit is 60 minutes, after file is opened

Material Provided on Exam 1

• A coding dictionary is provided at the beginning of the exam.
• The 3-letter abbreviation of amino acids may be used instead of the full name, if the 1 letter abbreviation is requested, provide that
• Exam content covers the information in Modules 1, 2, and 3

Purpose of Review Slides

• The slides are for reviewing major vocabulary and topics from Exam 1 material
• These slides are not part of the guided notes
• Incorporate the slides into the guided notes
• The slides serve as a general study guide

Introduction (Lectures 1–3)

• Key vocabulary to use includes Allele, Phenotype, Genotype, Homozygous, Heterozygous, Dominant, Recessive, Carrier, DNA, Mutation, Karyotype, Gene Therapy, and Genetic Counseling
• Various genetic disorders and their genetic basis are included, for example: Huntington's Disease, Sickle Cell Anemia, Cystic Fibrosis, Osteogenesis Imperfecta
• For dominant disorders, one copy of the disorder allele is needed.
• For recessive disorders, two copies of the disorder allele are needed
• Focus on the intersection of genetics and public health
• Discuss important ethical and public health issues involving gene therapy and genetic testing

Lecture 4: Cell Types and Components

• Covers major cell components and their functions: nucleus, mitochondria, ribosomes, endoplasmic reticulum (smooth and rough), Golgi apparatus, plasma membrane, and lysosomes
• Relate specific disorders to alterations in genes affecting specific cell parts. This includes Leber's disease, Long QT Syndrome, Cystic Fibrosis, and Tay-Sachs disease

Lecture 5: Chromosomes and the Cell Cycle

• Identify chromosomes by centromere location
• Differentiate between chromatids and chromosomes, their relationship to the stages of mitosis and meiosis
• Description of the stages in the cell cycle, relate them to chromosome structure
• Describe Karyotypes: how chromosomes are organized in a karyotype
• What can be learned from Karyotypes?
• Number of chromosomes in a normal human somatic cell
• FISH technique & chromosome preparation procedures

Lecture 6: Mitosis and Meiosis

• Describe the steps of mitosis and meiosis.
• Importance of meiosis in generating variation across generations through crossing over and independent assortment of chromosomes
• Define related vocabulary: mitosis, meiosis, stages of mitosis and meiosis, reductional division, equational division, crossing over (recombination), and synapse

Two Biological Goals of Meiosis

• Produce gametes with a haploid number of chromosomes (23 in humans)
• Maintain a constant number of chromosomes across generations through the alternation of meiosis and fertilization
• Introduce variability through the shuffling of maternal and paternal chromosomes during meiosis (approximately 8.4 million possible combinations in humans)
• Explain that crossing over allows for a combination of maternal and paternal alleles within each chromosome

Lecture 7: Gametogenesis, Nondisjunction, and Fertilization

• Types of cells involved in oogenesis and spermatogenesis, location of the process.
• Compare oogenesis and spermatogenesis
• Relate gametogenesis to meiosis and relate the chromosome numbers to each cell type
• Explain nondisjunction, when it occurs, and its outcomes
• Define related vocabulary: fertilization, syngamy, corona radiate, zona pellucida, acrosome; early developmental stages: zygote, fetus, embryo, etc.
• Describe male and female anatomy
• Describe early embryonic development

Lecture 8: Prenatal Testing and IVF

• Describe various prenatal tests (CVS, amniocentesis, cell-free fetal DNA testing), processes, and available information
• Situations where IVF may be necessary
• Guidelines for the number of embryos used in IVF treatment

Lecture 9: DNA, RNA, and Chromatin Structure

• Explain experiments leading to the structure of DNA & techniques
• Structure and components of DNA and RNA, and their differences
• Vocabulary and relevant diagrams: Complementary base pairing, hydrophobic interactions, antiparallel arrangement, plectonic coiling, and Watson-Crick model of DNA.
• Explain the direction of helical coil (right-handed or left-handed coil)
• Define chromatin, histones and relate to chromosome structure,

Lecture 10: DNA Replication

• Describe the Meselson and Stahl experiment and how it determined DNA replication is semiconservative
• Identify leading and lagging strands and the location of Okazaki fragments.
• Explain the function of Okazaki fragments in replication
• Describe how DNA polymerase forms phosphodiester bonds to create new strands that are antiparallel and complementary to the old strands. DNA replication occurs at multiple origins along the chromosome.
• DNA is produced from 5' to 3'
• Describe RNA primers used in DNA replication
• Describe the necessity and function of telomerase in replication

Lecture 11: Transcription, RNA Types, mRNA Processing

• Compare DNA and RNA
• RNA polymerase uses phosphodiester bonds to create RNA in an antiparallel and complementary fashion to the DNA template strand; this is produced in a 5' to 3' direction
• Coding and template strands (DNA) and their relationship to RNA (thymine vs. uracil)
• Describe types of RNA: mRNA, tRNA, rRNA, and snRNA, and their full names
• Describe the structure of genes including promotor, exon, and intron
• Significance of splicing of the primary transcript to create the mature mRNA

Lecture 12: The Genetic Code and Translation

• Describe the properties of the genetic code (degenerate, unambiguous, start and stop punctuation)
• Use a coding dictionary to translate mRNA
• Translation process with related vocabulary (codon, anticodon, ribosome, peptide bond, release factor)
• Use a given DNA sequence to create mRNA and a given mRNA sequence to create a protein

Example: Translate mRNA

• Example of translating mRNA to protein using a given mRNA sequence and the provided genetic code table.

Lecture 13: Regulation of Gene Expression and Epigenetics

• Diagram and describe the function of parts of a eukaryotic gene (promotor, intron, exon, and others)
• Describe the function of microarrays (gene chips)
• Define epigenetics and its connection to changes in gene expressions without changing DNA sequence
• Identify epigenetic changes (DNA methylation, histone modification, including histone tail acetylation).
• Indicate that modifications are inheritable

Lecture 14: DNA Sequencing, HGP, GINA

• Compare deoxyribose and dideoxyribose, explain Sanger sequencing theory
• Major participants and DNA sequencing approaches in the Human Genome Project (HGP)
• Potential uses of DNA sequencing data (1000 genomes project, 100,000 genomes project)
• Concerns about sequencing an individual's DNA
• Provisions and limitations of GINA (Genetic Information Nondiscrimination Act)

Additional Study Materials

• Each module includes review questions that can be used as study material
• Completed guided notes are also an excellent resource

Final Thoughts

• Best of luck on the exam