Chapter 1-2 Flashcards
What is biology?
The study of living things
List the four characteristics of living things.
- Ability to capture and use raw energy and materials (metabolism)
- Ability to sense and respond to the environment
- Ability to reproduce
- Ability to evolve
Why are viruses considered non-living?
They can’t replicate without a host
What are the levels of organization in nature starting from subatomic particles?
- Subatomic particles
- Atoms
- Molecules
- Organelles
- Cells
- Tissues
- Organs
- Organ Systems
- Multicellular Organisms
- Population
- Community
- Ecosystem
- Landscape
- Biosphere
What are producers, consumers, and decomposers?
- Producers (Autotrophs) – use sunlight to make their own food
- Consumers (Heterotrophs) – get their food by eating producers or other consumers
- Decomposers (Saprotrophs) – break down the tissues of dead producers and consumers
Who developed the binomial system of classification?
Carolus Linnaeus
What is the scientific name for humans?
Homo sapiens
List the eight categories of biological classification from broadest to most specific.
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is morphological classification?
Classification based on the number of toes/limbs and the structure of limbs
What is genetic classification?
Comparison of DNA and RNA sequences to reflect evolutionary history
What are the two main types of cells?
- Prokaryotic
- Eukaryotic
What is a prokaryotic cell?
A cell without a nucleus or internal organization
What is a eukaryotic cell?
A cell with a nucleus and membrane-bound organelles
How many domains of living things are there?
Three: Bacteria, Archaea, Eukarya
What are the four kingdoms of Eukarya?
- Protista
- Fungi
- Animalia
- Plantae
Define evolution.
Genetic shift in a population through time
What is DNA?
The molecule that carries the blueprints for living things
What is a gene?
A segment of DNA that gives an organism a physical trait
What is inheritance?
Acquisition of traits through the transmission of DNA from parents to offspring
Define mutation.
A heritable change in DNA
What is variation in a population?
The range of traits in a population due to mutations and inheritance
What is an adaptive trait?
A trait that helps an individual survive and reproduce
What is natural selection?
Change in a population over many generations where the environment favors individuals with adaptive traits
What is sexual selection?
Traits favored because they help attract mates, even if they are detrimental to survival
What is artificial selection?
Humans select traits they want in offspring and breed individuals with those traits
Define an element.
A pure substance made up of one kind of atom
What are the four most abundant elements found in living things?
- Hydrogen
- Carbon
- Oxygen
- Nitrogen
What is an atom?
The smallest unit of an element that retains the properties of that element
What are the three subatomic particles?
- Protons (positive charge)
- Neutrons (no charge)
- Electrons (negative charge)
What is atomic mass?
The number of protons plus the number of neutrons
What are isotopes?
Atoms of the same element with different numbers of neutrons than protons
What are ions?
Atoms with different numbers of electrons than protons, causing a charge
What determines an atom’s chemical properties?
The arrangement/configuration of electrons
What is a molecule?
Two or more atoms linked together by chemical bonds
What are ionic bonds?
Weaker bonds formed by the exchange of electrons and attraction between opposite charges
What are covalent bonds?
Strong bonds formed by sharing one or more pairs of electrons
What is a hydrogen bond?
Weak attraction between an electronegative atom in a polar covalent bond and an electropositive H atom
What are the unique properties of water?
- High specific heat
- Less dense as a solid than as a liquid
- Excellent solvent
- Cohesion and adhesion
Define a chemical reaction.
Occurs when chemical bonds are made or broken, changing a substance’s composition
What is pH?
A measure of the ratio of H+ to OH- in a solution
What is a buffer?
A substance that neutralizes acids and bases, helping to maintain a constant pH
