IB BIOLOGY Topic 3: Genetics

Genetics

The study of heredity and the transmission of characteristics (genes) to future generations.

Heredity

The transmission of genetic information from one generation to the next, leading to the diversity and variability observed in traits among individuals within a species.

DNA

The molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms.

Genes

Segments of DNA that contain the instructions for the production of specific proteins or functional RNA molecules, which determine the traits and characteristics of an organism.

Chromosomes

Structures made of DNA and proteins that carry genetic information in the form of genes.

Genetic Mutations

Changes or alterations in the DNA sequence that can lead to variations in traits and characteristics.

Adaptations

Genetic changes that enable organisms to better survive and reproduce in their environment.

Natural Selection

The process by which certain traits become more or less common in a population over time, based on their impact on survival and reproduction.

Genetic Testing

The analysis of an individual's DNA to identify genetic predispositions to diseases, determine ancestry, or assess the risk of passing on genetic disorders to offspring.

Gene Editing

The process of modifying or replacing specific genes in an organism's DNA to correct genetic disorders or enhance desired traits.

Karyotype

An organized array of a cell's chromosomes, used to assess an individual's genetic makeup, diagnose genetic disorders, and determine gender.

Allele

Different forms or variations of a gene that can occupy the same position (locus) on a chromosome.

Phenotype

The observable physical or biochemical characteristics of an individual resulting from the interaction between genes and the environment.

Genotype

The combination of alleles that an individual has for a given gene.

Homozygous

Having two identical alleles for a given trait.

Heterozygous

Having two different alleles for a given trait.

Dominant

An allele that is physically seen in a heterozygous individual.

Recessive

An allele that is not physically seen in a heterozygous individual.

Osteogenesis Imperfecta

A genetic disorder characterized by multiple bone fractures, decreased mobility, and other abnormalities related to the condition.

Marfan Syndrome

A genetic disorder characterized by long limbs, weakened aorta, and other associated symptoms.

Sickle Cell Anemia

A genetic disorder where an individual's blood cells are sickled instead of smooth and round, leading to health complications.

Cystic Fibrosis

A genetic disorder that causes the accumulation of thick mucus in the lungs, leading to respiratory infections and breathing difficulties.

Xeroderma Pigmentosum (XP)

A genetic disorder characterized by excessive sensitivity to UV light and an increased risk of skin cancer.

Prophase

The first stage of mitosis, where chromatin condenses into visible chromosomes, the mitotic spindle forms, and the nuclear envelope begins to disintegrate.

Prometaphase

The second stage of mitosis, where the nuclear envelope completely disassembles, chromatids become distinct, and the mitotic spindle fully forms.

Metaphase

The third stage of mitosis, where chromosomes align along the cell's equatorial plane, and spindle fibers attach to the centromeres.

Anaphase

The fourth stage of mitosis, where sister chromatids are pulled apart and move towards opposite ends of the cell, and the centromere divides.

Mitosis

The process of nuclear division in eukaryotic cells, resulting in two genetically identical daughter cells.

Genetic Diversity

The variety of different genetic traits and combinations within a population or species, promoting adaptability and survival.

Telophase

The stage of mitosis where chromatids begin to separate and move to opposite poles of the cell.

Cytokinesis

The cytoplasmic division of a cell at the end of mitosis or meiosis, resulting in the formation of two daughter cells.

Chromosome Preparation

The process of preparing chromosomes for analysis, such as using colchicine to destroy spindle fibers or a hypotonic salt solution to increase cell volume.

Homologous Chromosomes

Chromosomes that have the same length, centromere position, banding pattern, and genetic loci.

Karyotype

An organized array of a cell's chromosomes, used to identify genetic disorders.

FISH Technique

Fluorescent in situ Hybridization, a technique that uses fluorescent DNA probes to target specific chromosomal locations within the nucleus.

Meiosis

Cell division in a diploid cell that leads to gamete formation, consisting of two divisions:reductional division and equational division.

Phenotype

The appearance of an individual for a trait.

Genotype

The alleles (forms of genes) that an individual has for a particular trait.

GMO

Genetically modified organism, an organism whose genetic material has been altered through genetic engineering.

Mutation

An incorrect copy of DNA or a change in the DNA sequence.

Evolution

The process by which organisms develop and diversify over time from their earlier forms.

GMOs

Genetically modified organisms, organisms whose genetic material has been altered through genetic engineering.

Genetic Engineering

The process of inserting DNA directly into an organism to modify its genetic material.

Golden Rice

Genetically modified rice that contains a gene from corn to produce beta-carotene, which our bodies can use to produce vitamin A.

Golden rice

A genetically modified rice variety that has been fortified with beta-carotene to address vitamin A deficiency in developing countries.

GMOs

Genetically modified organisms that have been altered through genetic engineering techniques.

Genetic diversity

The variety of genes within a population or species, which is important for the adaptation and survival of organisms.

Gene drive

A genetic element that is passed from parent to progeny at a higher frequency than expected, causing the rapid increase of specific genes in a population.

Gene editing

The modification of an organism's DNA using techniques like CRISPR-Cas9 to make targeted changes to specific genes.

RNA interference (RNAi)

A biological process that regulates gene expression by inhibiting the translation or degrading mRNA molecules.

PCR

Polymerase Chain Reaction, a laboratory technique used to amplify a specific segment of DNA.

Electrophoresis

A technique used to separate DNA fragments based on their size using an electrical current.

Short Tandem Repeats (STRs)

Repeating sequences of DNA that vary in length between individuals and are used for DNA profiling in forensic analysis.

CODIS

Combined DNA Index System, a DNA database used for forensic identification purposes.

DNA Profiles

Genetic information obtained from individuals convicted of crimes, crime scenes, missing persons, relatives of missing persons, and unidentified human remains.

Partial Match

A situation where a complete match is not obtained, but a very close match is observed in the DNA database.

Familial DNA Searching

A method where family members are asked to submit their DNA for testing in order to find a perfect match.

Conflict between Solving Crimes and Protecting Privacy

The potential conflict that arises when using DNA evidence to solve crimes while also ensuring the protection of individuals' privacy rights.

The Innocence Project

A non-profit organization dedicated to exonerating wrongfully convicted individuals, advocating for criminal justice system reforms, and raising awareness and education about wrongful convictions and flaws in the justice system.

Exonerating Wrongfully Convicted Individuals

The Innocence Project's efforts to identify and secure the release of individuals who have been wrongly convicted of crimes they did not commit using DNA evidence, new forensic techniques, and legal advocacy.

Reforming the Criminal Justice System

The Innocence Project's advocacy for policy changes and legal reforms to prevent future wrongful convictions, addressing issues such as flawed forensic practices, eyewitness misidentification, and misconduct by law enforcement and prosecutors.

Raising Awareness and Education

The Innocence Project's role in raising public awareness about the prevalence of wrongful convictions and flaws in the justice system, providing educational resources, and engaging in public outreach to promote fair and just legal practices.