Mod 6: Genetic Change - Biology (OLIVIA Z)

Mutation

A change to the nucleotide base sequence of an organism’s DNA

Spontaneous mutation

Random, natural errors during DNA replication or meiosis

Mutagens

Environmental agents that bring about mutations (e.g. radiation)

Mutagenic

Something that causes a mutation

Induced mutation

Mutations that are caused by environmental agents

Electromagnetic radiation

Energy that can affect living organisms and is used in many biological and medical applications

Dimer

Cross-linked nucleotide

Ionising radiation

High energy radiation that frees electrons from atoms or molecules/turns them into ions

Free radical

An atom, molecule, or ion with an unpaired electron in its outermost shell, which makes it highly reactive and unstable

Intercalating agents

Chemicals that insert themselves into bonds between base pairs and alter the shape of DNA

Base analogues

Chemicals that are structural similar to the nitrogenous bases and are incorporated into the DNA sequence during replication in place of a base

Transposons

Jumping genes - sections of DNA that spontaneously fragment and relocate or multiply

Point mutation

Change to a single nucleotide in a gene

Chromosomal mutation

Movement of an entire gene to other parts of the same or different chromosomes

Aneuploidy

Abnormal number of chromosomes

Nonsense mutation

Mutation that causes a premature stop codon to be inserted into the DNA sequence (short polypeptide/synthesis ends too soon)

Frameshift mutation

A point mutation that involves the insertion or deletion of a nucelotide

Missense mutation

Point mutation where a single nucleotide change in a gene's DNA sequence leads to a different amino acid being incorporated into a protein

Silent mutation

A change in the DNA sequence that does not alter the amino acid sequence of a protein

Substitution

A point mutation where one nucleotide base is replaced by another (silent, missense or non-sense)

Deletion chromosomal mutation

A section of DNA is removed so entire genes are delected

Duplication/Insertion chromosomal mutation

A section of the chromosome is duplicated and inserted (sometimes more than once)

Inversion chromosomal mutation

A section of DNA is removed, turned 180, then reinserted

Translocation chromosomal mutation

A whole chromosome or segment of a chromosome becomes attached to or exchanged with a non-homologous segment

Germline mutations

Mutations to gametes; passed down to offspring

Somatic mutations

Mutations to body cells; not passed down to offspring

Exon

Coding DNA (part of gene that is expressed)

Intron

Non-coding DNA that is removed after transcription (i.e. not expressed)

Spliceosome

An enzyme that cuts the introns out of pre-mRNA

Promoter

Non-coding region of DNA before the gene + binding site for RNA polymerase, essential for transcription

Enhancer

Non-coding region of DNA before/after the gene that binds to transcription factors to increase the likelihood that a specific gene's transcription will occur

Activator proteins

Regulatory proteins that bind to specific DNA sequences to increase the rate of gene transcription

Silencer

Non-coding DNA sequence that represses transcription by binding repressor proteins to hinder the action of RNA polymerase

Repressor protein

A regulatory protein that binds to a specific DNA sequence (like an operator or silencer) and prevents transcription by blocking the RNA polymerase from binding to the promoter, effectively turning a gene or set of genes "off"

CRISPR-Cas 9

A gene-editing tool that uses a guide RNA to direct the Cas9 enzyme, which acts like molecular scissors, to cut DNA at a specific location

Biotechnology

the use of biological systems and living organisms, or parts of them, to create or modify products and processes

Evolution

The cumulative change in the heritable characteristics of a population across successive generations

Allele frequency

How often each allele for a gene occurs within a population

Gene pool

The total collection of all genes and their alleles, within a single population or species

Darwin’s Theory of Evolution by Natural Selection

Organisms with heritable traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to their offspring

Selective pressures

Environmental factors that drive evolution by influencing an organism's ability to survive and reproduce

Genetic drift

The change in the composition of a gene pool as a result of change or random events

Bottleneck effect

A sharp reduction in a population's size due to a random event like a natural disaster, causing a significant loss of genetic variation

Founder effect

A type of genetic drift where a new population is established by a small number of individuals from a larger population, leading to a loss of genetic variation

Gene flow

The introduction or removal of alleles due to immigration into a population or emigration out of a population

Speciation

The evolutionary process by which a new species is formed from a pre-existing one

Reproductive technology

Technologies which aid with the reproduction of an organism (e.g. IVF)

Genetic technology

Any technologies that manipulate the genetic material (DNA) to create products for human use (e.g. artificial insemination)

Genetic engineering

The direct manipulation of an organism’s genetic material (e.g. CRSPR)

Selective breeding/Artificial selection

The process where humans choose parents with desirable traits in the hopes that offspring will have a greater chance of inheriting these traits

Artificial insemination

Selective breeding of animals where a chosen female is inseminated with sperm from a chosen male

Artificial pollination

Selective breeding of plants where pollen from a chosen flower is manually transferred to the stigma of another flower

IVF

In vitro fertilisation (in glass) - involves fertilisation outside the female body in a glass petri dish

Whole organism cloning

A reproductive technology producing offspring that are genetically identical to parents

SCNT

Somatic cell nuclear transfer

Gene cloning

The production of identical copies of a gene

In vitro

A method where single genes are cloned in a lab using PCR for research

In vivo

A method where genes are cloned using bacteria

Vector

A virus or altered bacterium - DNA vehicles used to deliver foreign genetic material into a target cell

PCR

Polymerase chain reaction - a process used for cloning single genes

Recombinant DNA technology

The inserting of one or more genes from one species into the genome of another

Transgenic organism

An organism that has one or more genes from a different species

Cross breeding

The mating of animals or plants from different breeds, varieties, or populations within the same species to combine desirable traits

Clone

An organism that has the identical genetic makeup of the parent cell

Tissue culturing/Micropropagation

A cloning technique where cells from a plant are taken into a culture medium to grow and be planted out

Cutting/Vegetative propagation

A cloning technique where cuttings of a plant are used to produce new plants

Grafting

A cloning technique involving a attaching a cutting from one plant onto the trunk of another

Enucleation

The process of removing the nucleus from a cell

Gene

A section of DNA which codes for a specific protein

Locus

The position of a gene on a particular chromosome

Gene clone

An exact copy of a single gene

Restriction enzyme

Enzymes produced by bacteria used to cut/isolate DNA

Plasmid

Circular region of DNA

Transgene

A gene from another species that can be passed down to offspring

Micro-injection

A method of transgenesis using a micropipette and microscope to inject the gene into an egg cell

Biolistics

A method of transgenesis using DNA-coated gold particles that are fired into cells

Electroporation

A method of transgenesis where the cell membrane’s permeability is increased using an electrical current

Gene therapy

A healthy copy of a gene is inserted into the tissue of someone with a genetic disease

Bt cotton

A transgenic crop that incorporates genes from the soil bacterium Bacillus thuringiensis to produce insecticidal proteins

Monoculture

The agricultural practice of growing a single crop species

Scion

A detached living shoot, bud, or twig—typically from a desirable fruit or ornamental tree—that is grafted onto a separate rootstock to propagate a plant asexually

Rootstock

The bottom portion of a grafted plant

GMO

Genetically modified organism (gene added or removed to produce an altered phenotype)