Biology: Levels of Organization and Cell Biology

A set of vocabulary flashcards covering levels of biological organization, components of living things, cell theory, cell structure components, microscopy techniques, and prokaryotic versus eukaryotic cell features.

Atom

The smallest unit of a substance and the building blocks of all matter.

Molecule

Two or more atoms bonded together.

Cell

The smallest unit of life, composed of unique molecules.

Tissue

Specialized cells in a multicellular organism organized in patterns that allow them to perform a function.

Organs

Structures consisting of tissues that carry out specific tasks.

Organ System

Interacting tissues and organs that fulfill one or more body functions.

Organism

An individual that consists of one or more cells.

Population

Interbreeding individuals of the same species living in a defined area.

Community

All populations of all species living in a defined area.

Ecosystem

A community interacting with its physical and chemical environment, consisting of biotic and abiotic components.

Biosphere

The largest ecosystem; all regions of Earth where organisms live, including the planet crust, water, and atmosphere.

Cellular Basis

The principle that all living things consist of one or more cells.

Homeostasis

The process of responding to change and keeping the internal environment in good conditions to maintain balance.

Cell Theory

1. Every living organism consists of one or more cells. 2. The cell is the basic structural and functional unit of life, individually alive even as part of a multi-celled organism. 3. All living cells arise by division of preexisting cells.

Plasma Membrane

An outer barrier with a lipid bilayer structure that controls what enters and leaves the cell, enclosing cytosol, water, solutes, and metabolic activity.

Cytoplasm

The region inside a cell containing cytosol and all intracellular components, such as ribosomes and the cytoskeleton.

Organelle

A structure that carries out specific functions inside of a cell.

Robert Hooke

The scientist who first called structures 'cells'.

Antonie van Leeuwenhoek

Observed moving 'beasties' under a microscope in 1665 and referred to them as 'little boxes'.

Magnification

The act of making something look bigger than it is.

Resolution

The ability to see small details; a measure of detail.

Contrast

The difference of an object or structure compared to those in the same field of view.

Light Microscope (LM)

A microscope that utilizes visible light passing through a curved lens to illuminate, focus on, and reflect off a live sample, tissue, or whole cell at up to $1000\times$ magnification with a micrometer (\text{̠m}) scale bar.

Fluorescence Microscopy

A light microscopy technique that highlights parts of the cell in neon colors (with DNA usually appearing blue) for targets sized $200\text{--}600\text{ nm}$.

Electron Microscopy (EM)

A microscopy technique using magnetic fields and metal to view black-and-white images of dead subcellular organelles smaller than $200\text{ nm}$.

Transmission EM

An electron microscopy method that provides a 2D slice of a sample.

Scanning EM

An electron microscopy method that provides a 3D image of the surface of a sample.

Prokaryotic

Meaning 'before the nucleus'; describes single-celled organisms (bacteria and archaea) that lack a nucleus and membrane-bound organelles, representing the smallest and most metabolically diverse forms of life.

Peptidoglycan

The material composing the cell walls of bacteria.

Cell Wall (Prokaryotic)

A structure surrounding the plasma membrane, which can be covered by a sticky capsule.

Flagella

Prokaryotic structures (usually one per cell) used for motion.

Pili

Short, hair-like projections on prokaryotes that assist in movement.

Ribosomes

Cellular components where proteins and polypeptides are assembled.

Nucleoid

The region of cytoplasm in prokaryotes containing circular DNA.

Plasmids

Small DNA fragments carrying a few genes necessary for survival.

Biofilms

Microbial communities (bacteria, algae, fungi) of multiple intertwined species that share a common layer of sugars.

Eukaryotes

Organisms (protists, fungi, plants, animals) meaning 'true nucleus' that start life with a nucleus and membrane-enclosed organelles.

Which key feature of living organisms is best described as the transmission of DNA from parent to offspring

Inheritance

What is the main source of energy for producers?

Sunlight

When energy is transferred from one organism to another, some energy is lost to the environment due primarily to _____

The release of heat

What is the scientific definition of biology?

The scientific study of life

Producers are organisms that

Are able to produce their own food

Which of the following is not a feature shared by all living things?

They are able to produce their own food

At what level of organization does life begin?

Cell

What are the components of organ systems

tissues, cells, organs

includes all populations of all species in a given area

community

a community interacting with its environment

Ecosystem

What are the key features of life

Organisms are composed of one or more cells, Life is sustained by inputs of energy and nutrients, Organisms sense and respond to changes in their environment

What is the process in which organisms keep their internal conditions within tolerable ranges by sensing and responding appropriately to change

Homeostasis

Which phrase would most likely be used in a discussion of homeostasis

Limited range of variation

Mitochondria are an example of

organelles found within eukaryotic cells

Which of the following structures are found only in eukaryotic cells?

Golgi, rough er, nuclei

Which of the following are parts of both prokaryotic and eukaryotic cells

Cytosol, DNA, Plasma membrane

What structure allows only certain molecules to pass into or out of the cell

Cell membrane

What cellular structure contains most of the DNA

Nucleus

Which of the following are the only molecules built by ribosomes and rough endoplasmic reticulum (RER)

Proteins

Which of the following types of biological molecules are synthesized at the endoplasmic reticulum

proteins, lipids

he jellylike mixture of water and solutes enclosed by a cell’s plasma membrane is known as ____

Cytosol

The factory is run by a boss, but he or she rarely comes down to the factory floor. Instead, the boss sits in the office where all the blueprints and designs for the factory products are kept. The boss sends orders to the factory workers on the floor with instructions on what to make next as well as how much to make. The boss's office represents the

Nucleus

Products and components to other products are made on complex conveyor belts that run along the factory floor. There are two types of conveyor belts in this factory. One type of conveyor belt has many complex machines working along it; the machines are very efficient but only make a few types of products. This type of conveyor belt represents the

Rough ER

The other type of conveyor belt does not have any of those machines. Instead, the second type of conveyor belt takes some of the completed products from the first type of conveyor belt and uses them to process a wider variety of products. This type of conveyor belt represents the

Smooth ER

Completed products that have to leave the factory are sent to the shipping department. There they are checked for quality and packed into boxes, which will carry them out of the factory. The shipping department represents the

Golgi Body

When products and materials need to be moved around the factory, they are placed into boxes for more efficient transport. These transport boxes represent

Vesicles

Normal operations of the factory create a certain amount of factory waste. In addition, at times trash accidentally comes in from outside. The factory deals with waste by dumping it all into incinerators, which burn and break down unwanted materials. These trash incinerators represent

Lysosomes

What is a defining feature of a eukaryotic cell

Internal membranes surrounding organelles

A biofilm is often attached to a solid surface and may include all of the following except _______

Pili

Prokaryotes ___

are either bacteria or archaea

Positively charged subatomic particles that occur in the nucleus of atoms are called

Protons

An uncharged subatomic particle that occurs in the nucleus is called a

Neutron

negatively charged subatomic particles that move at high speed around the nucleus

Electron

Which of the following defines the atomic number of a given element

The number of protons in the atomic nucleus

Which of the following is defined as a chemical bond in which electrons are shared unequally between an atom with a slight negative charge and an atom with a slight positive charge

Polar covalent bond

The separation of charge into positive and negative regions

Polarity

An important property of water molecules is their capability to resist separating from one another called

Cohesion

attraction between a covalently bonded hydrogen atom and another atom taking part in a separate covalent bond

Hydrogen bonds

What is the pH of a solution that has a higher concentration of H+ ions than water

<7

Which of the following levels in the shell model of an atom can hold up to two electrons

The first shell

When a sodium atom loses a single electron to become a sodium ion, it becomes

Positively charged

When a chlorine atom gains a single electron to become a chloride ion, it becomes

Negatively charged

Which of the following is a measure of an atom’s ability to pull electrons away from another atom

Electronegativity

dissolves easily in water

Hydrophilic

cannot dissolve in water

Hydrophobic

substances that give up hydrogen ions in water

Acids

substances that accept hydrogen ions in water

Bases