Unit #3: Genetic Processes - Lesson #1: The Nature of Heredity

A complete set of vocabulary practice flashcards based on Unit #3, Lesson #1: The Nature of Heredity, covering DNA structure, genetics terminology, mutations, chromosomal organization, genomics, and modes of reproduction.

Genetics

The field of biology that studies how genetic information is passed from one generation of organisms or cells to the next.

Cell Theory

A biological theory from the mid-1800s stating that all living things are made of one or more cells, cells are the smallest units of living organisms, and new cells come from pre-existing cells through cell division.

Deoxyribonucleic Acid (DNA)

The molecule that stores and transmits hereditary genetic information from parent to offspring.

Nucleotide

The repeating structural unit of DNA composed of three main components: a pentose (5-carbon) sugar, a phosphate group, and a nitrogenous base.

Purine Bases

Nitrogenous bases containing $2$ nitrogen rings, specifically Adenine ($\text{A}$) and Guanine ($\text{G}$).

Pyrimidine Bases

Nitrogenous bases containing $1$ nitrogen ring, specifically Cytosine ($\text{C}$) and Thymine ($\text{T}$).

Complementary Base Pairing

The specific pairing of nitrogenous bases across DNA strands where Adenine ($\text{A}$) always binds with Thymine ($\text{T}$) and Guanine ($\text{G}$) always binds with Cytosine ($\text{C}$) via hydrogen bonds.

Rosalind Franklin

The scientist who determined using X-ray crystallography that DNA molecules form a helical shape.

James Watson and Francis Crick

The scientists who utilized Rosalind Franklin's experimental findings to discover that DNA is a double-stranded molecule arranged in a double helix.

DNA Backbone

The structural strand foundation of DNA composed of alternating phosphate groups and pentose sugars.

Point Mutations

Errors or alterations in the nitrogenous base sequence of DNA, which can have negative, positive, or neutral effects on an organism.

Base-Pair Substitution

A type of point mutation where one nucleotide in the DNA sequence is replaced by a different nucleotide.

Insertion

A type of point mutation where an additional nucleotide is inserted into the DNA sequence.

Deletion

A type of point mutation where a nucleotide is eliminated from the DNA sequence.

Sickle Cell Anemia

A genetic disorder resulting from a mutated form of hemoglobin that distorts red blood cells into a crescent shape and reduces their ability to transport oxygen throughout the circulation.

Chromatin

The long, thin, uncondensed form of DNA found in the nucleus during interphase that is not visible under a light microscope.

Chromosome

The condensed, compact, thread-like structure of DNA that becomes clearly visible under a microscope during mitosis.

Gene

A specific segment of DNA on a chromosome that codes for a particular hereditary trait.

Locus

The specific physical position or location of a gene on a chromosome.

Sister Chromatids

Two genetically identical copies of a chromosome produced during DNA duplication and joined together at the centromere.

Diploid Cells

Cells that contain two complete sets or copies of chromosomes ($2n$), such as body (somatic) cells.

Haploid Cells

Cells that contain half the standard number of chromosomes ($n$), such as sex cells (gametes).

Homologous Chromosomes

Pairs of chromosomes similar in length, centromere location, and banding pattern that contain matching genes, though not necessarily identical alleles.

Alleles

Different variations or alternative forms of the same gene located at a specific gene locus.

Genome

The complete sequence of DNA and genetic material found within every cell of an organism.

Human Genome Project

An international scientific research project (1990 to 2003) with the primary goals of identifying all $20\text{,}000\text{--}25\text{,}000$ human genes and sequencing the $3\text{ billion}$ base pairs that compose human DNA.

Coding DNA

The approximately $2\%$ of the human genome that actively codes for functional genes.

Non-Coding DNA

The approximately $98\%$ of the human genome that does not code for any functional genes.

Karyotype

A visual display of the complete set of an individual's chromosomes, arranged and paired by size, centromere location, and banding patterns during metaphase to detect chromosomal abnormalities.

Autosomes

The non-sex chromosomes, consisting of chromosome pairs $1$ through $22$ in human somatic cells.

Sex Chromosomes

The $23\text{rd}$ pair of human chromosomes ($\text{XX}$ for female and $\text{XY}$ for male) that determines the biological sex of an organism.

Asexual Reproduction

A form of reproduction involving a single parent that produces offspring genetically identical to the parent without requiring a mate.

Sexual Reproduction

A form of reproduction involving the fusion of two sex cells from different parents, yielding genetically diverse offspring that inherit half their genetic material from each parent.

Vegetative Propagation

A mode of asexual reproduction where a new, genetically identical plant develops from parts of the parent plant.

Budding

A mode of asexual reproduction in which a new individual grows as an outgrowth or bud from the parent's body and later detaches as an identical organism.

Fragmentation

A mode of asexual reproduction where a body segment breaks off from a parent organism and regenerates into a complete, genetically identical individual.

Binary Fission

A mode of asexual reproduction common in single-celled and prokaryotic organisms where the cell duplicates its genetic material and divides into two equal parts via cytokinesis.

Spore Formation

A mode of asexual reproduction where an organism breaks into multiple specialized reproductive cells (spores), each capable of developing into an organism identical to the parent.