Understanding Genetics, Chemistry: Key Terms & Concepts
Key Concepts in Genetics and Chemistry
Mendel experimented by extracting traits from garden peas containing plant cells, including germinal elements, and placing them in the female gamete. He selected only 22 varieties of peas.
A gene is a specific sequence of nucleotides on one of the chromosomes, referenced to the scalar.
An allele is one of the alternative forms of a gene.
The genotype is an individual’s genetic content, their DNA.
The phenotype refers to the expression of the genotype in a specific environment. Phenotypic features include both physical and behavioral traits.
Meiosis: is a type of cell division present in sexually reproducing organisms.
Gametes: are the germ cells that lead to fertilization. Female gametes are the ovules, and male gametes are the spermatozoa.
Fertilization: is the union of two reproductive cells or gametes (haploids) in sexual reproduction, resulting in a zygote (diploid).
Homozygous: describes an organism that has identical alleles for a specific gene, meaning it possesses two identical copies of a gene for a given trait on both chromosomes.
Pure Line: A pure line refers to an organism that is purebred and has not been crossed with any other.
The First Law of Uniformity: states that if two purebreds are crossed for a specific trait, the first generation offspring will all be identical.
The Second Law of Segregation: states that during gamete formation, each pair of alleles segregates so that each gamete receives only one allele for each trait.
The Third Law of Independent Assortment: Mendel concluded that different traits are inherited independently of each other, provided they are not linked. The inheritance pattern of one trait does not affect the inheritance pattern of another.
Mutation: A genetic mutation is an alteration or change in genetic information.
Mutagens: are physical, chemical, and biological agents that cause mutations.
Chemistry Terms
Periodic Table
Molecule: The smallest division of a substance.
Chemical Element: Each class of atom.
Chemical Formula: A representation using symbols and numbers of the chemical elements.
Atom: Every particle that constitutes a molecule.
Simple Molecule: Formed by identical atoms. Compound Molecule: Formed by different atoms.
Ions: Atoms with a positive or negative electrical charge.
Chemical Symbol: A letter that represents a chemical element.
Atomic Number: The number of protons in the nucleus of an atom.
Mass Number: Neutrons + protons in the nucleus.
Number of Protons: The atomic number of each atom.
Electrons: Equal to the number of protons and neutrons in the nucleus.
Calculating the Number of Neutrons: Mass Number – Atomic Number.
Electronic Configuration: The location of electrons in the orbitals.
Metals vs. Nonmetals: Notable differences exist between metals and nonmetals.
Generally solid, liquid, or gas.
Without gloss.
Does not conduct electricity.
Atomic Models
Joseph Thomson: Represented the atom as a compact spherical mass with a positive charge.
Ernest Rutherford: Proposed that protons were in a nucleus and electrons in orbits.
Niels Bohr: Proposed that electrons have fixed paths around the nucleus.
James Chadwick: Discovered the presence of uncharged neutrons in atomic nuclei.
Werner Heisenberg: Located protons and neutrons in the nucleus and electrons in energy levels.