Designer Genes and Biotechnology

Flashcards covering key vocabulary and concepts from lecture notes on genetics, DNA, RNA, and biotechnology.

Genotypic Ratio

The ratio of different genotypes (e.g., AA, Aa, aa) resulting from a cross.

Phenotypic Ratio

The ratio of different physical traits (phenotypes, e.g., dominant, recessive) resulting from a cross.

Punnett Square

A diagram used to predict the genotypes of offspring from a genetic cross. Named after Reginald C. Punnett.

Single-Factor (Monohybrid) Cross

A genetic cross involving only one trait (one pair of alleles).

Two-Factor (Dihybrid) Cross

A genetic cross involving two traits (two pairs of alleles).

Incomplete Dominance

A form of inheritance where the heterozygous phenotype is an intermediate between the two homozygous phenotypes.

Codominance

A form of inheritance where the heterozygous phenotype displays both homozygous phenotypes.

Sex-Linked Traits

Traits associated with genes located on the sex chromosomes (usually the X chromosome).

Multiple Alleles

The presence of more than two alleles for a particular gene in a population. An individual may have two of those alleles in some combination.

Lethal Alleles

Alleles that cause death before an individual can reproduce.

Epistasis

A form of gene interaction where one gene masks or inhibits the expression of another gene.

Pedigree

A graphical representation of the inheritance pattern of a trait through a family tree.

DNA (Deoxyribonucleic Acid)

A molecule consisting of a phosphate group, a deoxyribose sugar, and a nitrogenous base.

Nitrogenous base

A heterocyclic ring containing both nitrogen and carbon atoms. (Adenine, Guanine, Thymine, Cytosine)

Purines

Nitrogenous bases with two rings (Adenine and Guanine).

Pyrimidines

Nitrogenous bases with one ring (Thymine and Cytosine).

Nucleoside

Consists of a deoxyribose sugar and a base (heterocyclic rings).

Nucleotide

Nucleosides with phosphate groups.

Chromatin

A complex of loose DNA, histones, and RNA within the nucleus of a cell.

Euchromatin

The most actively transcribed form of DNA.

Heterochromatin

A more tightly packed form of DNA, typically responsible for structural functions.

Chromatid

A copy of a chromosome attached to the original chromosome at the centromere.

Sister Chromatids

Identical chromatids formed during DNA replication.

Non-Sister Chromatids

Chromatids appearing in meiosis when a paternal and maternal chromosome are paired together.

Base Pairing

The pairing of nitrogenous bases in DNA: Adenine with Thymine and Cytosine with Guanine.

Chargaff's Rule

States that an organism should have equal percentages of adenine and thymine and cytosine and guanine.

DNA Replication

The process by which a cell duplicates its DNA before cell division.

Helicase

The enzyme that splits the two individual strands of DNA by breaking the hydrogen bonds between them.

DNA Polymerase

The enzyme that replicates DNA molecules to build a new strand of DNA.

Primase

The enzyme that makes the primer so that DNA Polymerase can figure out where to go to work.

Primer

A short segment of RNA that marks the starting point for DNA replication.

Ligase

The enzyme that helps glue DNA fragments together.

SSB Proteins

Proteins that keeps the individual strands apart as helicase is splitting them apart by breaking the hydrogen bonds between them.

Topoisomerase

The enzyme that keeps the DNA from supercoiling.

Okazaki Fragments

Short fragments of DNA synthesized on the lagging strand during DNA replication.

Semi-Conservative Replication

Each new DNA molecule contains one old (original) strand and one newly made strand.

RNA (Ribonucleic Acid)

A single-stranded nucleotide chain consisting of a ribose sugar and hydroxyl group.

mRNA (Messenger RNA)

Encodes the sequence of amino acids that becomes a protein.

tRNA (Transfer RNA)

Transports amino acids to ribosomes during translation.

rRNA (Ribosomal RNA)

Along with ribosomal proteins, rRNA makes up the ribosome which is molecular machine the that translates mRNA into proteins.

Non-coding RNAs (ncRNA)

This refers to any RNAs that do not result in a protein product. This includes tRNA and rRNA.

microRNA (miRNA)

Short sections of RNA that can anneal to matching complementary strands of RNA, silencing expression by preventing their translation.

Small nuclear RNA (snRNA)

snRNA is involved in splicing of pre-mRNA.

Pre-messenger RNA (pre-mRNA)

This refers to newly transcribed RNA that has not be processed by post-transcriptional processing.

Transcription

The process of transcribing DNA into pre-mRNA so that it can be later translated into proteins.

Translation

The process of translating the mRNA created during transcription into a protein.

Codon

A sequence of three mRNA bases that corresponds to a specific amino acid or a stop signal during translation.

Anticodon

A sequence of three tRNA bases that is complementary to a codon on mRNA.

Start Codon

AUG; signals the beginning of translation.

Stop Codon

UAA, UAG, or UGA; signals the end of translation.

Polypeptide

A sequence or chain of amino acids.

Mitosis

The process of cell division in somatic cells that results in two identical daughter cells.

Cell Cycle

The general life cycle of a cell, including interphase and mitosis.

Interphase

The part of the cell cycle that does not constitute mitosis; it is the phase in between two cell divisions, when the cell is growing.

Prophase

The first phase of mitosis during which chromatin condenses into chromosomes.

Metaphase

The phase of mitosis during which chromosomes line up at the metaphase plate.

Spindle Checkpoint

Ensures that every chromosome is properly aligned and attached to the microtubules.

Anaphase

The phase of mitosis during which sister chromatids separate and move to opposite poles of the cell.

Telophase

The final phase of mitosis during which new nuclear envelopes form.

Cytokinesis

The division of the cytoplasm to form two separate daughter cells.

Meiosis

The process of cell division that is unique to germ cells, producing haploid eggs and sperm from diploid progenitors.

Crossing Over

Process during prophase I of meiosis where homologous chromosomes exchange genetic material.

DNA Repair

Mechanisms cells use to repair damage to their DNA.

Direct Reversal

DNA repair mechanism that directly reverses damage, such as pyrimidine dimers formed by UV light.

Excision Repair

DNA repair mechanisms that remove damaged nucleotides and replace them with the correct nucleotides.

Base Excision Repair (BER)

A process that repairs damages to a single base using glycosylases.

Nucleotide Excision Repair (NER)

DNA repair mechanism used when a large portion of the DNA helix is distorted.

Post Replication Repair

Also known as translesion synthesis, where replication past DNA lesions occurs.

Transcriptional Gene Expression

Gene expression controlled during or after transcription.

Post-Transcriptional Processing

Modifications to pre-mRNA to turn it into a full-fledged mRNA.

snRNPs (Small Nuclear Ribonucleoproteins)

Recognize splice sites, and join together additional proteins to form an assembly known as the spliceosome.

Alternative Splicing

A process by which different RNA are produced from the same primary transcript by mixing and matching axons.

microRNA (miRNA)

A small sequence of RNA that regulates gene expression.

Operon

A group of genes transcribed together by a single promoter.

Epigenetics

The study of changes in organisms not caused by the alteration of the genetic code.

Phylogenetics

he study of evolutionary relationships.

Hardy-Weinberg Equilibrium

A model that describes the conditions under which allele and genotype frequencies in a population will remain constant from generation to generation.

Sequencing

Determining the specific order that nucleotides are in.

Chain-Termination Method (Sanger Sequencing)

A method of sequencing, typically used on strands of DNA that have 900 base pairs or less.

Next Generation Sequencing (NGS)

Several different ways to sequence DNA. It is faster and cheaper than Sanger sequencing since many sequencing reactions can take place at once, it is very low-cost, and the reactions are much smaller.

RNA Sequencing (RNA-Seq)

Is the use of Next Generation Sequencing to reveal how much RNA is in a sample at a given moment and is replacing microarrays in many labs.

Tn-Seq

Determines genetic interactions and can determine the frequency of mutations. However, it is limited to bacterial studies.

Microarray

Consists of a small solid surface with various known single-stranded segments of DNA attached.

RFLP Analysis

A DNA sample is broken into pieces and digested by restriction enzymes and the resulting restriction fragments are separated according to their lengths by gel electrophoresis.

Molecular Cloning

The process of inserting recombinant DNA into various host organisms - for example, certain types of bacteria - and replicating them.

Polymerase Chain Reaction (PCR)

A method of quickly making billions of copies of a desired section of DNA.

Gel Electrophoresis

A technique in which charged molecules are separated by being pulled through a gel.

Blotting

A method for identifying specific biomolecules in a sample mixture.

Gene Therapy

The process of introducing genes into a patient in order to cure a disease.

CRISPR-Cas Technology

A bacterial defense mechanism that can be used to target and edit DNA in specific locations.

Bioethics

An intersection of ethics and technology, and studies the way that advancements in science and medicine interact with society and the environment.

Genetic Disorders

Inherited medical conditions caused by abnormalities in the DNA.

Polysomy

When an individual is having more than two copies of a particular chromosome.

Monosomy

When an individual has one copy of a chromosome rather than the normal two copies.

Addition (Insertion)

The addition of nucleotides into a DNA sequence.

Deletion

The removal of nucleotides from a DNA sequence.

Translocation

When the parts of a chromosome are rearranged, occasionally resulting in a genetic disorder.

Karyotype

A chart that shows each chromosome.