General Science, Genetics, Evolution, Ecology, and Body Systems Lecture Review

Comprehensive vocabulary flashcards covering general science methods, genetics, meiosis, evolutionary theories, ecology levels, and human body systems.

Independent Variable

What you change on purpose in an experiment; it goes on the x-axis.

Dependent Variable

What you measure or observe in an experiment; it goes on the y-axis.

Inference

A logical conclusion based on evidence or data patterns.

Line Graph

A chart that shows change over time, such as population growth.

Bar Graph

A chart used to compare different categories, such as favorite foods.

Pie Chart

A chart that shows percentages or parts of a whole.

Dominant Allele

An allele that shows up if only one copy is present, represented by an uppercase letter.

Recessive Allele

An allele that only shows if two copies are present, represented by a lowercase letter.

Homozygous

An organism that has two of the same alleles for a trait (e.g., $BB$ or $bb$).

Heterozygous

An organism that has two different alleles for a trait (e.g., $Bb$).

Genotype

The genetic makeup of an organism, such as $BB$, $Bb$, or $bb$.

Phenotype

The physical appearance of an organism, such as brown eyes or being a tall plant.

Codominance

A form of inheritance where both alleles are fully expressed, such as red and white spots on cow fur or $AB$ blood type.

Incomplete Dominance

A form of inheritance where traits blend together, such as a red flower and white flower producing pink offspring.

Polygenic Traits

Traits controlled by many genes, such as height, skin color, and eye color.

Sex-Linked Traits

Traits carried on the X chromosome, making males more likely to be affected (e.g., color blindness or hemophilia).

Principle of Segregation

Mendel's law stating that alleles separate during gamete formation.

Principle of Independent Assortment

Mendel's law stating that different genes separate independently during Meiosis I (Prophase I crossing over).

Haploid

Cells containing half the number of chromosomes; in humans, this number is $23$.

Crossing Over

An event in Prophase I of Meiosis where homologous chromosomes exchange DNA to create genetic diversity.

Nondisjunction

A failure of chromosomes to separate correctly, leading to disorders like Down syndrome ($\text{trisomy 21}$).

Karyotype

A picture of chromosomes arranged in pairs used to identify chromosomal disorders.

Artificial Selection

The process where humans choose specific traits, such as in dog breeding or crop production.

Natural Selection

The process where nature selects traits that improve an organism's survival and reproduction.

Homologous Structures

Structures with the same physical anatomy but different functions, providing evidence of common ancestry (e.g., human arm and whale fin).

Analogous Structures

Structures with different physical anatomy but the same function, providing evidence of convergent evolution (e.g., butterfly wing and bird wing).

Vestigial Structures

Structures with little or no current function, such as the appendix or wisdom teeth.

Fitness

The ability of an organism to survive and reproduce in its environment.

Stabilizing Selection

A type of selection where middle traits are favored, such as medium birth weight in babies.

Directional Selection

A type of selection where one extreme trait is favored over others.

Disruptive Selection

A type of selection where both extremes are favored, which can lead to speciation.

Geographic Isolation

A physical barrier, like mountains or oceans, that separates populations and can lead to speciation.

Genetic Drift

A change in allele frequency due to random events, such as the Founder Effect or the Bottleneck Effect.

Convergent Evolution

When different species evolve similar traits because they live in similar environments, like sharks and dolphins.

Absolute Dating

A method using radioactive decay to determine the exact age of a fossil.

Cladogram

A diagram used to show evolutionary relationships based on derived characters.

Symbiosis

A close relationship between two different species, categorized as mutualism, parasitism, or commensalism.

Keystone Species

A species critical to ecosystem stability, such as sea otters controlling sea urchin populations.

Competitive Exclusion Principle

The rule that two species cannot occupy the same niche forever.

Carrying Capacity

The largest population size that an environment can support based on available resources.

10\text{% Rule}

The principle that only about 10\text{%} of energy is transferred upward from one trophic level to the next.

Homeostasis

The maintenance of stable internal conditions within the body.

Negative Feedback

A mechanism that returns the body to normal ranges, such as sweating to lower body temperature.

Positive Feedback

A mechanism that amplifies a change until an end point is reached, such as childbirth contractions.

Enzymes

Proteins that speed up chemical reactions, including amylase, lipase, and protease.

Cellular Respiration Equation

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$$

Arteries

Blood vessels that carry blood away from the heart, usually oxygenated except for the pulmonary artery.

Capillaries

Tiny blood vessels that serve as the site of gas exchange between blood and tissues.

Insulin

A hormone used to lower blood sugar levels as part of a negative feedback loop.