Year 10 Comprehensive Genetics Glossary and Terminological Guide

Fundamentals of Genetic Molecules and Structures

• Deoxyribonucleic Acid (DNA)

  • Definition: A complex molecule that serves as the code for genetic information.

  • Etymological Components:

    • Deoxy: Meaning less oxygen.

    • Ribo: Referring to a specific type of sugar.

    • Nucleic: Indicating its location in the nucleus.

    • Acid: Describing a substance with a low $pH$.

  • Related Concepts: Nucleus, gene, and nucleotide.

• Nucleotide

  • Definition: A chemical compound that acts as the building block of DNA. It is composed of a phosphate group, a sugar, and a nitrogenous base.

  • Etymological Components:

    • Nucleo: Meaning the centre.

    • Ide: A suffix denoting a chemical compound.

  • Related Concepts: Nitrogenous base and DNA.

• Nitrogenous Base

  • Definition: A compound responsible for linking nucleotides together.

  • Etymological Components:

    • Nitro: Signifying that it contains nitrogen.

    • Base: Describing a substance with a high $pH$.

  • Related Concepts: DNA and nucleotide.

• Biomolecule

  • Definition: Chemical compounds that occur naturally within living organisms.

  • Etymological Components:

    • Bio: Meaning life.

    • Molecule: Atoms that are chemically bonded together.

  • Examples: DNA, proteins, carbohydrates, and lipids.

Cellular Classification and Organelles

• Eukaryotic

  • Definition: Cells that possess membrane-bound organelles.

  • Etymological Components (Greek):

    • Eu: Meaning true.

    • Karyon: Meaning kernel.

  • Related Concepts: Nucleus, multicellular organisms, and organelles.

• Prokaryotic

  • Definition: A simple type of cell that lacks membrane-bound organelles.

  • Etymological Components (Greek):

    • Pro: Meaning before.

    • Karyon: Meaning kernel.

  • Primary Example: Bacteria.

• Organelle

  • Definition: Structures found within cells that are encased in a membrane and carry out specific biological functions.

  • Etymological Components (Greek):

    • Organ: Meaning to work.

  • Related Concepts: Eukaryotic cells, nucleus, and membrane.

Chromosomal Structure and Packaging

• Chromosome

  • Definition: A threadlike structure composed of protein and nucleic acids located in the nucleus of most living cells. It carries genetic information in the form of genes.

  • Etymological Components:

    • Chromo: Meaning colour.

    • Soma: Meaning body.

  • Related Concepts: Chromatid and nucleus.

• Chromatid

  • Definition: One of the $2$ identical halves that make up a replicated chromosome. These halves are joined together at a centromere during the process of cell division.

  • Etymological Components:

    • Chrome: Meaning colour.

  • Related Concepts: Chromatin and chromosome.

• Chromatin

  • Definition: This term refers to the mixture of proteins and DNA that constitutes the chromosomes.

  • Related Concepts: Chromosome and chromatid.

• Histone

  • Definition: A specific protein that acts as a structural support for a chromosome, often functioning like a spool for DNA.

  • Etymological Components:

    • Histo: Meaning tissue stricture.

  • Related Concepts: Chromatin, protein, and spool.

Gene Expression and Protein Production

• Gene

  • Definition: The fundamental unit of heredity. Genes are composed of specific sequences of DNA and serve as instructional sets for the creation of protein molecules.

  • Etymological Components:

    • Genos: Meaning race or offspring.

  • Related Concepts: Nucleotides, DNA, and allele.

• Enzyme

  • Definition: Biological catalysts, which are almost exclusively proteins. They accelerate chemical reactions in living organisms without being used up by the reaction.

  • Etymological Components (Greek):

    • Enzumos: Meaning leavened.

  • Related Concepts: Catalyst, protein, and chemical reaction.

• Protein Synthesis

  • Definition: The cellular process of building proteins based on instructions provided by DNA.

  • Etymological Components:

    • Synthesis: Meaning to place together.

  • Component Processes: Transcription and translation.

• Transcription

  • Definition: The specific process of creating an RNA copy of a gene's DNA sequence.

  • Etymological Components:

    • Trans: Meaning across.

    • Script: Meaning write.

  • Related Concepts: $mRNA$, DNA, and enzyme.

• Translation

  • Definition: The cellular process where ribosomes build proteins by following the sequence encoded in messenger RNA ($mRNA$).

  • Etymological Components:

    • Translate: Meaning rewritten or the transfer of meaning.

  • Related Concepts: Enzyme, ribosome, protein synthesis, and transcription.

Reproduction and Cell Division

• Mitosis

  • Definition: The process of nuclear division in eukaryotic cells that results in the creation of $2$ daughter cells that are genetically identical to the single parent cell.

  • Etymological Components (Greek):

    • Mitos: Meaning thread.

  • Related Concepts: Replication and cell division.

• Meiosis

  • Definition: The biological process responsible for the production of gametes, such as sperm and ova.

  • Etymological Components (Greek):

    • Meiosis: Meaning to lessen.

  • Related Concepts: Diploid, haploid, and gametes.

• Gamete

  • Definition: A reproductive cell found in plants or animals.

  • Etymological Components (Greek):

    • Gamos: Meaning marriage.

  • Examples: Ovum and sperm.

  • Related Concepts: Meiosis and haploid.

• Asexual Reproduction

  • Definition: A process in which a single parent produces offspring that are genetically identical to itself, effectively creating clones.

  • Etymological Components (Greek):

    • a: A prefix meaning without or not.

  • Related Concepts: Identical and clone.

• Sexual Reproduction

  • Definition: The creation of new organisms facilitated by the combination of genetic information from $2$ individuals of different sexes.

  • Etymological Components (Latin):

    • Sexualis: Meaning copulation.

  • Related Concepts: Gamete, zygote, and the $X$ and $Y$ chromosomes.

Chromosomal Sets and Inheritance Types

• Diploid

  • Definition: Describes a cell containing $2$ complete sets of chromosomes, with one set inherited from each parent.

  • Etymological Components (Greek):

    • Diplous: Meaning double.

  • Related Concepts: Haploid, chromosomes, and sexual reproduction.

• Haploid

  • Definition: Describes a cell that possesses only a single set of chromosomes.

  • Etymological Components (Greek):

    • Haploos: Meaning single.

  • Related Concepts: Meiosis, diploid, and gametes.

• Autosomes

  • Definition: Any chromosome in a cell that is not classified as a sex chromosome.

  • Etymological Components (Greek):

    • Autos: Meaning self.

    • Soma: Meaning body.

  • Related Concepts: Chromosome, diploid, recessive, and dominant.

• Sex-Linked

  • Definition: Genetic traits or characteristics that are specifically determined by genes located on the sex chromosomes, which are identified as $X$ or $Y$.

  • Related Concepts: Autosomal, inheritance, and chromosome.

Principles of Genetics and Traits

• Dominant

  • Definition: The version of a gene that is considered stronger or has a higher likelihood of being expressed.

  • Etymological Components (Greek):

    • Dominari: Meaning governing or ruling.

  • Related Concepts: Genotype, phenotype, and recessive.

• Recessive

  • Definition: A gene variation that can be hidden or masked by the presence of a dominant gene.

  • Etymological Components (Latin):

    • Recess: Meaning tending to recede.

  • Related Concepts: Genotype, phenotype, and dominant.

• Genotype

  • Definition: The specific genetic makeup or unique combination of alleles an organism receives for a specific trait or gene.

  • Etymological Components (Greek):

    • Genos: Meaning race or offspring.

    • Tupos: Meaning type.

  • Related Concepts: Dominant, recessive, and phenotype.

• Phenotype

  • Definition: The set of an organism's observable behaviors, traits, or characteristics.

  • Etymological Components (Greek):

    • Pheno: Meaning to show.

  • Related Concepts: Recessive, dominant, and genotype.

• Homozygous

  • Definition: An organism that possesses $2$ identical alleles (versions) for a specific gene, having inherited the same version from each biological parent.

  • Etymological Components (Greek):

    • Homos: Meaning like or same.

    • Zygous: Meaning yoked; the pairing of genetic material.

  • Related Concepts: Heterozygous, allele, pure line, hybrid, and chromosomes.

• Heterozygous

  • Definition: An organism that possesses $2$ different alleles for a specific gene, having inherited a different version from each parent.

  • Etymological Components (Greek):

    • Hetero: Meaning different.

    • Zygous: Meaning paired or yoked.

  • Related Concepts: Homozygous, allele, pure line, hybrid, and chromosome.

• Allele

  • Definition: A variant or alternative form of a specific gene that occupies a particular site on a chromosome.

  • Etymological Components (German):

    • Allellomorph: Meaning form or one another.

  • Related Concepts: Gene, genotype, and chromosome.

• Co-dominant

  • Definition: A pattern of inheritance where $2$ alleles are expressed equally in the phenotype, rather than one being dominant over a recessive one.

  • Etymological Components:

    • Co: Meaning together.

  • Related Concepts: Incomplete dominance, dominant, and recessive.

• Incomplete Dominance

  • Definition: A situation where alleles are not fully expressed, leading to the emergence of a new, intermediate phenotype.

  • Related Concepts: Dominant and genotype.

• Mutation

  • Definition: A permanent change in an organism's DNA sequence, which serves as a modification to the genetic instructions.

  • Etymological Components (Latin):

    • Mutat: Meaning to alter or change.

  • Related Concepts: DNA, gene, and allele.

Genetic Analysis Tools

• Pedigree

  • Definition: A diagram used to map ancestry, biological relationships, and the patterns of inheritance for health conditions or traits across multiple generations.

  • Etymological Components (Norman/French):

    • Pe de grue: Meaning Crane's foot.

  • Related Concepts: Genotype, phenotype, dominant, and recessive.

• Punnett Square

  • Definition: A square-shaped diagram utilized to predict the expected genotypes resulting from a specific breeding experiment or genetic cross.

  • Origin: Named after Reginald C. Punnett.

  • Related Concepts: Dominant, recessive, and genotype.