Topic A-D Study Guide Answers

Atom

The smallest unit of an element.

Molecule

Two or more atoms bonded together.

Organelle

Functional components within a cell.

Cell

Basic unit of life.

Tissue

Group of similar cells performing a function.

Organ

Structure composed of multiple tissues.

Organ system

Group of organs working together.

Organism

A single, living individual.

Population

Group of organisms of the same species.

Community

Interacting populations in an area.

Ecosystem

Living and non-living components of an area.

Biosphere

All ecosystems on Earth.

Fundamental Unit of Life

The cell.

Population vs. Community

A population consists of individuals of the same species, while a community includes different species interacting.

Energy Source

The Sun.

Homeostasis Example

Sweating to regulate body temperature.

Asexual Reproduction

One parent, identical offspring.

Sexual Reproduction

Two parents, genetically unique offspring.

Importance of Sexual Reproduction

Provides genetic diversity.

Primary Producers

Organisms that produce their own food using sunlight (photosynthesis).

Consumers

Organisms that eat plants or other organisms.

Decomposers

Organisms that break down organic matter.

Evolution

A change in the genetic composition of a population over time.

Biodiversity

Variety of life forms on Earth.

Importance of Biodiversity

Ensures ecosystem stability and resilience.

Three Domains of Life

Bacteria, Archaea, Eukarya.

Four Eukaryotic Kingdoms

Plantae, Animalia, Fungi, Protista.

Taxonomic Hierarchy

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

Scientific Method

Steps: Observation, Hypothesis, Experiment, Data Analysis, Conclusion.

Hypothesis vs. Theory

A hypothesis is a testable prediction, while a theory is a well-supported explanation.

Matter

Anything that has mass and takes up space.

Most Abundant Elements in Living Cells

Carbon, Hydrogen, Nitrogen, Oxygen (CHON).

Trace Elements

Iron (Fe), Zinc (Zn).

Parts of an Atom

Protons, Neutrons, Electrons.

Atomic Number

Number of protons in an atom.

Isotope

Atoms with the same number of protons but different neutrons.

pH Scale

Measures acidity or alkalinity of a solution.

Neutral pH

7 on the pH scale.

Acidic pH

Below 7 on the pH scale.

Basic pH

Above 7 on the pH scale.

Monomer

The basic building block of polymers.

Polymer

A large molecule made up of monomers.

Endergonic Reactions

Require energy; products have more energy.

Exergonic Reactions

Release energy; reactants have more energy.

ATP Structure

Adenine, ribose, and three phosphate groups.

Autotroph

Organisms that produce their own food.

Heterotroph

Organisms that consume organic matter.

Site of Photosynthesis

Chloroplast.

Glucose

The end product of photosynthesis.

Function of Organelles

Components within cells that perform specific functions.

Plant Cells vs. Animal Cells

Two structures found in plant cells but not in animal cells are the cell wall and chloroplasts.

Cell Theory

All organisms are made of one or more cells; all cells come from preexisting cells.

Difference between Cytoplasm and Cytosol

Cytoplasm includes cytosol, organelles, and other cell components; cytosol is the fluid part of the cytoplasm.

Benefits of Bacteria

Aid in digestion, nitrogen fixation, and have applications in biotechnology and medicine.

Common Bacteria

Escherichia coli (E. coli) is a common bacteria.

Eukaryotic Organisms

Organisms belonging to the domain Eukarya.

Bacterial Cell vs Eukaryotic Cell

Bacterial cells are simpler and unicellular, while eukaryotic cells are complex and may be unicellular or multicellular.

Organelles Composition

Organelles are made of proteins, lipids, and nucleic acids.

Photosynthesis

The process by which green plants use sunlight to synthesize foods with the help of chlorophyll.

Cell Respiration

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Enzyme

A protein that acts as a catalyst to speed up chemical reactions in cells.

Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water through a semi-permeable membrane.

Cell Membrane

The protective barrier that regulates what enters and leaves a cell.

Chromosome

A structure made of DNA and proteins that contains genetic information.

Gene

A segment of DNA that codes for a specific trait.

Mutation

A change in the DNA sequence that can lead to variations in traits.

Mitosis

A type of cell division that results in two identical daughter cells.

Meiosis

A type of cell division that reduces the chromosome number by half, producing gametes.

Genetic Variation

Differences in DNA among individuals within a population.

Natural Selection

The process through which organisms better adapted to their environment tend to survive and produce more offspring.

Ecosystem Services

Benefits humans obtain from ecosystems, including provisioning, regulating, cultural, and supporting services.

Biomagnification

The process by which the concentration of toxins increases as it moves up through the food chain.

Symbiosis

A close and often long-term interaction between two different biological species.

Commensalism

A type of symbiosis where one species benefits while the other is neither helped nor harmed.

Mutualism

A symbiotic relationship in which both species benefit.

Parasitism

A symbiotic relationship where one organism benefits at the expense of another.

Trophic Level

Each step in a food chain or food web, representing a level of energy transfer.

Carrying Capacity

The maximum population size that an environment can sustain indefinitely.

Habitat

The natural home or environment of an organism.

Niche

The role or function of an organism or species within an ecosystem.

Biotic Factor

Living components of an ecosystem that affect the environment.

Abiotic Factor

Non-living chemical and physical parts of the environment that affect living organisms.

Carbon Cycle

The series of processes by which carbon compounds are interconverted in the environment.

Nitrogen Cycle

The process by which nitrogen is converted between its various chemical forms.

Water Cycle

The continuous movement of water within the Earth and atmosphere.