Science Exam Review: Evolution, Chemistry, and Homeostasis

Flashcards covering evolution, natural selection, chemical indicators, lab safety, exothermic and endothermic reactions, homeostasis, and the properties and formulas of acids and bases.

How is scientific equilibrium defined in contrast to complete inactivity?

In science, equilibrium does not mean everything stops moving; instead, opposing processes occur at equal rates, resulting in overall stability.

What is natural selection and how does it drive evolution?

Natural selection is the primary mechanism of evolution where organisms with favorable traits are more likely to survive and reproduce, passing those traits to their offspring.

What six components describe how natural selection works within a population?

Variation, Overproduction, Competition, Survival of the Fittest, Inheritance, and Adaptation.

What causes variation among individuals in a population?

Variation is caused by mutations and genetic recombination.

What is heredity in the context of evolutionary concepts?

Heredity is the passing of traits from parents to offspring through genes.

What are two specific types of isolation that can cause groups of the same species to evolve into different species over time?

Geographic isolation (such as mountains or rivers) and reproductive isolation.

How is an adaptation defined in evolution?

An adaptation is an inherited characteristic that improves an organism's survival and reproduction, such as thick fur in polar bears.

How do fossils provide evidence for evolution?

Fossils are preserved remains or traces of ancient organisms that show how species have changed over time, such as ancient horse fossils showing gradual changes in size.

What is biogeography and what is a classic example of biogeographical evidence for evolution?

Biogeography is the study of where organisms live; an example is Darwin's finches on the Galápagos Islands, where similar species in nearby regions suggest common ancestry.

What are homologous structures and what do they indicate?

Homologous structures are similar structures with different functions (such as a human arm, whale flipper, and bat wing) that indicate common ancestry.

What are analogous structures?

Analogous structures are different structures with similar functions due to similar environments, such as bird wings and insect wings.

What are vestigial structures?

Vestigial structures are reduced structures with little or no function, such as the human appendix or whale pelvic bones.

What is the function of chemical indicators and what five types are identified in the notes?

Indicators are substances that change color depending on pH to identify acidic, basic, or neutral solutions. The five types are Litmus Paper, Phenolphthalein, Methyl Orange, Universal Indicator, and Natural Indicators.

How are acids, bases, and salts utilized in medicine and agriculture?

In medicine, antacids neutralize stomach acid and saline solutions are used for IV fluids and wound cleaning; in agriculture, lime reduces soil acidity and fertilizers contain various salts.

What are the specific functions of Gloves, Goggles, Apron / Lab Gown, and Mask in laboratory safety?

Gloves keep hands safe from chemicals, heat, and sharp objects; Goggles protect eyes from splashes, sparks, and flying debris; Apron / Lab Gown shields clothes and body from spills and stains; Mask prevents inhalation of fumes, powders, or harmful particles.

How do bond breaking and bond formation relate to net energy changes in chemical reactions?

Breaking bonds absorbs energy, while forming new bonds releases energy; the net energy change determines if a reaction is exothermic or endothermic.

What are the key characteristics and examples of an exothermic reaction?

Exothermic reactions release energy (heat, light, sound) to the surroundings, cause surroundings to become warmer (temperature increases), and result in products having less energy than reactants. Examples include burning wood, combustion, and cellular respiration.

What are the key characteristics and examples of an endothermic reaction?

Endothermic reactions absorb energy from the surroundings, cause surroundings to become cooler (temperature decreases), and result in products having more energy than reactants. Examples include photosynthesis, instant cold packs, cooking food, and dissolving ammonium nitrate.

What is homeostasis and what are its Greek word origins?

Homeostasis is the body's ability to maintain a stable internal environment despite external changes. It comes from the Greek words 'Homeo' (meaning same) and 'Stasis' (meaning standing still).

What is the normal level maintained for body temperature by homeostasis?

Homeostasis maintains body temperature at about $37\,^\circ\text{C}$.

What is the Arrhenius definition and key properties of an acid?

Arrhenius acids release $\text{H}^+$ ions in aqueous solutions. Properties include tasting sour, turning blue litmus paper red, conducting electricity in solution, reacting with metals to produce hydrogen gas, reacting with carbonates to produce $\text{CO}_2$, having a pH less than $7$, and being corrosive.

What are the chemical formulas and uses for Acetic Acid, Citric Acid, Carbonic Acid, and Hydrochloric Acid?

Acetic Acid ($\text{CH}_3\text{COOH}$) is found in vinegar; Citric Acid ($\text{C}_6\text{H}_8\text{O}_7$) is in citrus fruits; Carbonic Acid ($\text{H}_2\text{CO}_3$) is in soft drinks; Hydrochloric Acid ($\text{HCl}$) serves as stomach acid and in cleaning materials.

What is the Arrhenius definition and key properties of a base?

Arrhenius bases release $\text{OH}^-$ ions in aqueous solutions. Properties include tasting bitter, feeling slippery/soapy, turning red litmus paper blue, conducting electricity in solution, having a pH greater than $7$, and neutralizing acids.

What are the chemical formulas and common uses for Potassium Hydroxide, Calcium Hydroxide, and Sodium Hydroxide?

Potassium Hydroxide ($\text{KOH}$) is used in liquid soap; Calcium Hydroxide ($\text{Ca(OH)}_2$) is used in construction and agriculture; Sodium Hydroxide ($\text{NaOH}$) is used in soap making.