Feedback Mechanisms and Mendel's Laws of Inheritance

Vocabulary flashcards covering the components and examples of feedback mechanisms (homeostasis) as well as foundational genetics and Mendel's laws of inheritance.

Stimulus

Anything that causes a change that the body needs to respond to, such as a temperature change, pain, dehydration, or a rise in blood glucose.

Receptor

The detector component in a feedback mechanism that senses internal or external environmental changes.

Thermoreceptors

Receptors located in the skin and hypothalamus that detect changes in temperature.

Photoreceptors

Receptors located in the retina of the eye that detect light.

Mechanoreceptors

Receptors located in the skin and ears that detect pressure, touch, and sound vibrations.

Baroreceptors

Receptors located in the arteries that detect changes in blood pressure.

Chemoreceptors

Receptors located in blood vessels and the brain that detect changes in chemicals, such as $CO_2$, $O_2$, or blood pH.

Control Center

The component in a feedback mechanism (such as the hypothalamus or endocrine system) that determines how the body should respond to maintain balance.

Effector

The part of the body (such as sweat glands, muscles, kidneys, or pancreas) that executes the response to correct a change.

Osmoreceptors

Receptors in the hypothalamus that detect low water levels when the body becomes dehydrated.

Negative Feedback Mechanism

A feedback process that reverses or counteracts a change to return the body to normal; it is the most common type of feedback in the body.

Positive Feedback Mechanism

A feedback process that amplifies or increases a change, pushing it further until a final event occurs (such as oxytocin release during childbirth).

Genetic Inheritance

The passing of traits from parent organisms to their offspring.

Gregor Mendel

An Austrian monk known as the father of Genetics who gardened and grew peas in the mid-1800s, demonstrating that hereditary units are responsible for trait inheritance.

Genes

The hereditary units of organisms responsible for carrying information from parents to offspring, determining characteristics, and sometimes causing disorders.

Genotype

The unique sequence of DNA or the two alleles that an organism inherits for a particular gene (such as homozygous dominant PP, homozygous recessive pp, or heterozygous Pp).

Phenotype

The observable trait of an organism resulting from the expression of one or more genes, such as brown hair, AB blood type, or blue eye colour.

Dominant Allele

An allele that is expressed when either one or both copies are present, overruling a recessive allele.

Recessive Allele

An allele that is only expressed when two copies are present.

Codominance

A pattern of inheritance in which both alleles of a gene are distinctly and fully expressed (e.g., a flower displaying both purple and white spots).

Incomplete Dominance

A pattern of inheritance in which both alleles are partially expressed, resulting in an intermediate phenotype (e.g., a mix of purple and white producing violet).

Law of Dominance

Mendel's law stating that if two alleles are different (heterozygous), only the dominant trait will be visible, while the recessive trait remains hidden.