Essentials of Genetics - Chapter 1

Flashcards covering key concepts from the Introduction to Genetics chapter, including CRISPR-Cas, the history of genetics, DNA structure and function, and biotechnology.

What is CRISPR-Cas?

A molecular mechanism found in bacteria with the potential to rewrite DNA sequences of genes; clustered regularly interspersed short palindromic repeats.

What are the advantages of CRISPR-Cas over other gene editing methods?

More accurate, more efficient, more versatile, and easier to use.

How does CRISPR-Cas function in bacteria?

It's a "seek and destroy" mechanism used by bacteria to fight viral infections. The RNA molecule seeks viral DNA and recruits Cas nuclease to cut and destroy it.

What is the role of RNA in CRISPR-Cas?

RNA molecule "seeks" viral DNA by binding to a matching sequence; recruits Cas nuclease.

What is the role of Cas in CRISPR-Cas?

Cas (CRISPR-associated) refers to nuclease or DNA cutting enzyme.

What are some potential uses of CRISPR-Cas in the laboratory?

Repairing mutations related to genetic disorders like Cystic fibrosis, Huntington disease, Sickle-cell disease, and Muscular dystrophy. Also, to prevent mosquitos from carrying malaria.

What is the significance of Darwin's HMS Beagle Voyage?

Darwin's travels provided geological, geographical, and biological observations that led to the theory of evolution by natural selection.

What is the key concept presented in Darwin's 'The Origin of Species'?

Existing species arose from other ancestral species by descent with modification, with natural selection as the mechanism of evolutionary change.

What was Mendel's contribution to genetics?

Mendel's quantitative data on peas showed traits are passed from parents to offspring in predictable ways, laying the foundation of genetics.

What is the Chromosome Theory of Inheritance?

Inherited traits are controlled by genes residing on chromosomes and are faithfully transmitted through gametes.

What happens during Mitosis?

Chromosomes are copied and distributed; each daughter cell receives a diploid set of chromosomes identical to the parental cell.

What is the outcome of Meiosis?

Gamete formation with a reduction in chromosome number; gametes receive only half the number of chromosomes (haploid, n).

Define alleles.

Alternate forms of a gene (e.g., eye color).

Define mutations.

Any heritable change in DNA sequence; the source of genetic variation.

Define genotype.

Set of alleles for a given trait.

Define phenotype.

Expression of the genotype producing observable features.

What did Avery, MacLeod, and McCarty's research in 1944 demonstrate?

DNA (nucleic acid), not protein, is the carrier of genetic information in bacteria.

Describe the structure of DNA as described by Watson and Crick.

A long ladder-like macromolecule that twists to form a double helix, made of four nucleotides - Adenine, Guanine, Thymine, and Cytosine.

What are the key differences between RNA and DNA?

RNA is usually single-stranded, contains ribose instead of deoxyribose, and contains uracil (U) instead of thymine (T).

What is transcription?

DNA strand is used to construct a complementary RNA sequence (mRNA) in the nucleus which then moves to the cytoplasm.

What is translation?

Synthesis of proteins directed by information encoded in mRNA, where codons specify the insertion of specific amino acids into the protein.

What is the role of tRNA in protein assembly?

tRNA recognizes information in mRNA codons and carries the proper amino acid for protein assembly during translation.

How do mutations in genes affect phenotype?

They can modify, alter, or eliminate a protein's usual function, leading to an altered phenotype. (e.g., Sickle-cell anemia)

What is the cause of Sickle-cell anemia?

A mutant form of hemoglobin due to a mutation in the gene encoding β-globin, resulting in an amino acid substitution.

What is the role of Restriction Endonucleases in Recombinant DNA Technology?

REs cut and inactivate invading viral DNA at specific sites. They are key to allowing for recombinant DNA molecules.

What is biotechnology?

The use of recombinant DNA technology and molecular techniques to make a product.

What is a transgenic organism?

An organism with genetically modified crops with genes for herbicide resistance, insects and nutritional enhancement.

What is genomics?

Studies structure, function, and evolution of genes and genomes.

What is proteomics?

Identifies set of proteins present in cells under a given set of conditions and studies their function and interactions.

What is bioinformatics?

Creation of hardware and software for processing nucleotide and protein data.

What is forward genetics?

Relies on naturally occurring mutations or intentionally induced mutations.

What is reverse genetics?

DNA sequence for gene of interest is known, and its role and function are studied using gene knockout method.

What are some characteristics of model organisms?

Easy to grow, short life cycle, produce many offspring, and allow for straightforward genetic analysis.

Name four model organisms

Drosophila melanogaster, Mus musculus, Viruses: T-phages and lambda phages, Microbes: Bacteria Escherichia coli and yeast Saccharomyces cerevisiae