Genetics and Molecular Biology

These flashcards cover key terms and concepts from genetics and molecular biology based on the lecture notes.

Genetics

The study of gene structure, heredity, and variation.

Gene

The functional unit made up of DNA.

Heredity

The passing of genetic factors from parents to offspring.

Variation

Any difference between individuals in a species.

Allele

One of two or more versions of a genetic sequence at a specific region on a chromosome.

Trait

A specific characteristic of an individual.

Cross Pollination

Produces a plant that has two different parents.

Autosome

Non-sex chromosomes in humans, there are 22 pairs.

Dominant

An allele that influences a trait even if only one copy is present.

Recessive

An allele that only shows its effect if two copies are inherited.

Carrier

An individual with one copy of a recessive allele.

Genotype

The set of genes in an organism's DNA.

Phenotype

The physical appearance or characteristics of an organism.

Homozygous

Having two identical alleles for a trait.

Heterozygous

Having two different alleles for a trait.

Hybrid

An offspring produced from the cross-breeding of genetically different varieties or species.

Gregor Mendel

The monk known for his experiments with pea plants and the principles of inheritance.

Law of Dominance

In a cross of pure traits, only one trait will appear in the offspring.

Law of Segregation

Each gene segregates during gamete formation, resulting in each gamete carrying only one allele.

Law of Independent Assortment

Different genes independently separate from one another when reproductive cells develop.

Punnett Square

A diagram used to predict the genotypes of offspring from a cross.

Codominance

A condition where both alleles are fully expressed in the phenotype.

Incomplete Dominance

A condition where one allele is not completely dominant over another, resulting in a mixed phenotype.

Multiple Alleles

A gene that exists in more than two forms.

Polygenic Traits

Traits controlled by two or more genes.

Sex-Linked Inheritance

The inheritance of genes located on sex chromosomes.

Pleiotropy

A condition where one gene influences multiple traits.

Autosomal Dominant

A pattern of inheritance where affected individuals have an affected parent.

Autosomal Recessive

A pattern of inheritance where both parents are carriers and the trait may skip generations.

X-Linked Dominant

Genetic disorders where affected females are more common due to paternal transmission.

X-Linked Recessive

Genetic disorders more frequent in males, often affected individuals appear in every generation.

Nucleic Acids

Biomolecules, such as DNA and RNA, that store genetic information.

Nucleotide

The building block of nucleic acids.

Chargaff’s rule

The principle that A=T and G=C in DNA.

Base pairing

The hydrogen bonding between nitrogenous bases in DNA.

Polynucleotide

A chain of nucleotides linked by phosphodiester bonds.

Protein

Large, complex biomolecules made up of amino acids.

Primary Structure

The unique sequence of amino acids in a protein.

Secondary Structure

The local folded structures that form within a protein due to hydrogen bonding.

Tertiary Structure

The three-dimensional arrangement of a protein.

Quaternary Structure

The arrangement of two or more polypeptide chains in a protein.

Hemoglobin

A protein in red blood cells that carries oxygen.

Enzymatic proteins

Function: Selective acceleration of chemical reactions
Example: Digestive enzymes catalyze the hydrolysis bonds in food molecules.

Defensive proteins

Function: Protection against disease
Example: Antibodies inactive and help destroy viruses and bacteria.

Storage proteins

Function: Storage of amino acids
Examples: Casein, the protein of milk, is a major source of amino acids for baby mammals. Plants have storage proteins in their seeds. Ovalbumin is the protein of egg white, used as an amino acid source for the developing embryo.

Transport proteins

Function: Transport of substances
Examples: Hemoglobin, the iron-containing protein of the vertebrae blood, transports oxygen from the lungs to the other parts of the body. Other proteins transport molecules across membranes, as shown here.

Hormonal proteins

Function: Coordination of an organism's activities
Example: Insulin, a hormone secreted by the pancreas, causes other tissues to take up glucose, thus regulating blood sugar concentration.

Contractile and motor proteins

Function: Movement
Examples: Motor proteins are responsible for the undulations of cilia and flagella. Actin and myosin proteins are responsible for the contrac-tion of muscles

Receptor proteins

Function: Response of cell to chemical stimuli
Example: Receptors built into the membrane of a nerve cell detect signaling molecules released by other nerve cells.

Structural proteins

Function: Support
Examples: Keratin is the protein of hair, horns, feathers, and other skin appendages. Insects and spiders use silk fibers to make their cocoons and webs, respectively. Collagen and elastin proteins provide a fibrous framework in animal connective tissues.