Grade 11 Biology Review: Evolution, Genetics, and Animal Systems

Vocabulary flashcards covering detailed Grade 11 Biology concepts including evolutionary theories, genetic inheritance, DNA structure, cell division, and animal organ systems.

Radiometric Dating

A technique used by scientists to estimate the Earth as approximately $4.54$ billion years old.

Inheritance of Acquired Characteristics

Jean-Baptiste Lamarck's theory that organisms change during their lifetime and pass traits gained during life to their offspring.

Natural Selection

The process where individuals with favorable traits survive and reproduce more often, leading to population evolution over time.

Uniformitarianism

Charles Lyell's theory that geological processes occur slowly and the same way today as they did in the past, suggesting Earth is very old.

Fitness

In evolutionary terms, the ability of an organism to survive and achieve reproductive success.

Mutation

A change in DNA that creates new alleles and serves as the ultimate source of genetic variation.

Hardy-Weinberg Principle

A mathematical model used to determine allele frequencies, assuming a population is not evolving, expressed by the formula $p^2 + 2pq + q^2 = 1$.

Bottleneck Effect

A genetic drift event occurring when a population suddenly becomes very small due to disasters, resulting in reduced genetic diversity.

Founder Effect

Genetic drift that occurs when a small group starts a new population, carrying only a subset of the original population's alleles.

Prezygotic Barriers

Reproductive isolating mechanisms that prevent fertilization, such as habitat, temporal, behavioral, mechanical, or gametic isolation.

Postzygotic Barriers

Isolating mechanisms that occur after fertilization, including hybrid inviability and hybrid sterility.

Allopatric Speciation

Speciation that occurs due to geographic isolation, such as a mountain range separating populations.

Sympatric Speciation

Speciation that occurs without a geographic barrier, often through polyploidy or behavioral changes.

Stabilizing Selection

A pattern of selection where the average phenotype is favored and extreme variations are removed.

Disruptive Selection

Selection where both extremes of a phenotype are favored and the middle is selected against, which can lead to speciation.

Homologous Structures

Structures with the same ancestry and similar bone structure but different functions, resulting from divergent evolution.

Analogous Structures

Structures with different ancestry but the same function, resulting from convergent evolution.

Macroevolution

Evolution occurring on a large scale over long periods of time, including the formation of new species.

Catastrophism

Georges Cuvier's theory that Earth experienced sudden catastrophes causing mass extinctions, after which new species appeared.

Allele

Different versions of the same gene, such as brown or blue alleles for eye color.

Law of Segregation

Mendel's law stating that allele pairs separate during meiosis so that only one allele enters each gamete.

Incomplete Dominance

An inheritance pattern where neither allele is completely dominant, producing a blended phenotype in heterozygotes.

Codominance

An inheritance pattern where both alleles are expressed equally without blending, such as in AB blood type or roan cows.

Purines

Larger DNA nitrogen bases with a double ring structure; specifically Adenine (A) and Guanine (G).

Tetrad

A pair of homologous chromosomes consisting of four chromatids that forms only during Prophase I of meiosis.

Crossing Over

The exchange of DNA between homologous chromosomes during Prophase I, which increases genetic variation.

Bile

A substance produced by the liver and stored in the gallbladder that emulsifies fats into tiny droplets.

Villi and Microvilli

Structures in the small intestine that increase surface area for the major site of nutrient absorption.

Alveoli

Tiny air sacs in the lungs surrounded by capillaries where gas exchange occurs via diffusion.

Boyle's Law

The principle that pressure and volume are inversely related, explaining the mechanism of inhalation and exhalation.

Tidal Volume

The volume of air inhaled or exhaled during a normal breath, which is approximately $500\,mL$.

Pulmonary Artery

The only artery in the human body that carries deoxygenated blood, moving it from the heart to the lungs.

SA Node

Known as the pacemaker of the heart, it is located in the right atrium and initiates the heartbeat.

QRS Complex

The wave on an ECG that represents ventricular depolarization and contraction.

Vasodilation

The widening of blood vessels to increase blood flow to the skin as a response to heat stress.