Sect 5 Quiz Hard

Molecular Genetic Techniques

• Molecular Genetic Techniques enable understanding of DNA mutations, recombinant DNA technology, and various molecular biological techniques.
• Different types of DNA mutations affect proteins, impacting their structure and function.
• Recombinant DNA technology is used to identify, clone, express, and study genes.
• Techniques like Northern, Southern, Western blotting, microarray, PCR, and DNA sequencing are used in biological, clinical, and forensic science.

Genesis Chapter 1 and 2

• Genesis 1 and 2 describe God's creation of life.
• Natural biological laws govern human reproduction and ensure the continuation of life.
• Cloning involves the transfer of genetic material to create life by artificial means.
• Some Christian denominations (like the Seventh-day Adventist Church) condemn human cloning but find animal research with cloning acceptable.

Genetic Analysis of Mutations to Identify and Study Genes

• Strategies exist to link genes to function, structure, and genomic location.
• Classical genetics isolates mutant organisms for gene cloning and studying the protein-encoded biochemical activity
• Observing biochemical activity in a gene product isolates the gene, and sequence analysis of protein-coding sequences can lead to protein-coding sequences.
• Mutations alter the DNA sequence, potentially changing gene function and phenotype.
• Mutations can be substitutions (synonymous, missense, nonsense), frameshifts or indels.
• Chromosomal mutations (inversions, deletions, insertions, translocations) affect the structure of multiple genes.

Haploids and Diploids

• Haploid organisms have one copy of each chromosome and their phenotype is determined by that one copy.
• Diploid organisms have two copies of each chromosome and two copies of each gene and phenotypes.
• Alleles are different forms of a gene.
• Homozygous diploids have the same alleles.
• Heterozygous diploids have different alleles.
• Phenotypic expression depends on whether alleles are recessive or dominant.

Segregation of Mutations

• Dominant and recessive mutations exhibit specific patterns in genetic crosses.
• Random segregation of paternal and maternal chromosomes occurs during meiosis, resulting in various combinations in daughter cells.
• Mitosis is somatic cell division, and meiosis is involved in gamete formation.
• In diploid organisms, recessive mutations are masked by normal alleles.
• Manifestation of a mutant phenotype in diploids necessitates mutations in both alleles.

Conditional Mutations

• Phenotypes can be modified depending on environmental conditions (permissive or restrictive)
• Temperature-sensitive mutants are examples of conditional mutations.

Complementation Analysis

• Complementation analysis is used when multiple recessive mutations show similar phenotypes to determine if they affect the same gene.
• Heterozygosity for mutations in separate genes leads to a wild-type phenotype.

Synthetic Lethal Mutations

• Synthetic lethal mutations exhibit a more severe phenotype than single mutations in the same or related genes.
• This observation suggests an interaction or dependency among proteins.
• Useful in evaluating protein interactions and determining redundant proteins.

DNA Cloning and Characterization

• DNA cloning produces identical DNA molecules.
• Recombinant DNA involves sequences from different sources.
• Restriction endonucleases cut DNA at specific sites, DNA ligase joins fragments.
• Cloning involves incorporating DNA fragments into a vector, introducing it into host cells that replicate it, and isolating the recombinant DNA.
• Restriction enzymes recognize specific short DNA sequences (restriction sites).
• Cleavage can result in sticky ends (overhangs) or blunt ends.
• DNA ligase joins complementary sticky or blunt ends.

Plasmid Vectors

• Plasmids are circular extra-chromosomal DNA molecules that replicate independently of the host chromosome.
• They can carry a variety of genes or sequences and often include a selectable marker (drug resistance gene).
• Polylinker (MCS) contains multiple restriction sites for cloning.

Phage Vectors

• Bacteriophages are useful vectors for cloning large DNA fragments.
• They infect host cells and replicate.
• The genes for the lytic cycle are removed for cloning.

Cosmids

• Cosmids are hybrid vectors that combine features of bacteriophages and plasmids.
• They are suitable for cloning much larger DNA fragments.

BACs, YACs, and HACS

• BACs (bacterial artificial chromosomes), YACs (yeast artificial chromosomes) and HACS (human artificial chromosomes) are specialized vectors for cloning extremely large DNA fragments.
• Crucial for studying larger genomic regions and whole chromosomes.

DNA Libraries

• Genomic libraries contain representatives of all DNA segments from a given organism.
• cDNA libraries contain mRNA-derived DNA; useful in analyzing gene expression.
• Libraries are created using various vectors.

Screening DNA Libraries

• Screening is used to isolate specific DNA sequences from a large population of clones based on their function or sequence.
• Techniques like polymerase chain reaction (PCR) and hybridization-based methods identify desired sequences in a library.
• Useful for isolating specific expressed genes and regulatory genes.

Blotting Techniques

• Southern blotting detects specific DNA fragments within a complex mixture.
• Northern blotting detects specific mRNA within a mix.
• In situ hybridization allows researchers to study mRNA expression directly within a sample (like tissues).

DNA Microarrays

• DNA microarrays simultaneously assess the expression levels or relative abundance of thousands of genes in different conditions or cell types.

PCR

• PCR amplifies a specific DNA region exponentially.
• Primers, heat stable polymerase, DNA template are needed
• The cycles of heating and cooling facilitate the amplification. -PCR has applications in diagnostics, cloning, and genetic analysis.

Fusion Proteins

• Fusion proteins combine different proteins, providing a means for studying protein function, detection, and purification.

Identifying and Locating Human Disease Genes

• Autosomal and X-linked inheritance patterns are used in analysis.
• Variations in DNA sequences (like SNPs, RFLPs, and STRs) can be used as genetic markers.
• Methods such as sequencing and hybridization used to map genes linked to disease traits.

Inactivating the Function of Specific Genes in Eukaryotes

• Strategies for inactivating specific genes.
• One approach uses homologous recombination to target mutations or disruptions in genes in embryonic stem (ES) cells.
• Insertion of selectable markers improves gene knockout.
• Generating knockout mice (inserting genes into the germ line of mice), studies of gene function using CRISPR-Cas9 system.

RNA interference (RNAi)

• RNAi interferes with gene expression by destroying mRNA molecules with complementary sequences, offering means for functional inactivation of genes without sequence change.

Genome Editing

• CRISPR-Cas9 is a powerful tool to edit DNA at specific locations, replacing or modifying targeted gene sequences

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