Biology Test

A _ _ electron microscope involves bringing the charged tip of a probe extremely close to the specimen so the electrons tunnel through the small gap between the specimen and the tip.

Scanning tunneling

what german scientists identified that tissues consist of cells.

Schwann and Scheilden

Which uses magnets to aim a beam of electrons at a thin slice of cells?

TEM

selective permeability

A property of a plasma membrane that allows some substances to cross more easily than others.

Schleiden

Determined that all plants are made of cells

Which cell type contains a nucleus and membrane-bound organelles?

Eukaryotic

Which type of cells contain a nucleus and other organelles that are bound by membranes?

Eukaryotic

Which are used in optical microscopes to magnify objects?

Lenses and visible light

What technology did Robert Hooke and Anton van Leeuwenhoek use to view living organisms and discover cells?

Microscope

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Which is a central organelle that contains the cell's genetic material in the form of DNA?

Nucleus

Which term describes the boundary that helps control what enters and leaves the cell?

Plasma Membrane

All cells have a structure called a _ _, that helps control what eneters and leaves the cell

Plasma membrane

exothermic

Releases heat

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

What distinguishes STMs from SEMs and TEMs?

STM can be used with live specimens.

Golgi apparatus

a flattened stack of tubular membrane that modefies proteins and packages for distribution outside of the cell.

plasma membrane

a flexible boundary that controls the movement of substances into and out of the cell.

cytoskelelton

a framework for the cell within the cytoplasm.

endoplasmic reticulum

a highly folded membrane that is the site of protein synthesis.

mitochondria

a membrane bound organelle that makes energy available to the rest of the cell.

vacuole

a membrane bound vescile for the temporary storage of materials.

phospholipid bilayer

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, head out tail in

lysosome

a vescle that contains digestive enzymes for the breakdown of excess or worn out cellular substances.

Only in plant cell

cell wall, chloroplast, central vacuole

nucleus

control center with directions and production of proteins and cell divisions.

osmosis

diffusion of water across a selectively permeable membrane

Chloroplast

double memembrane organelles with thylakoids conaining chloryphyll, where photosynethisis takes place.

Which theory explains the origin of cell diversity as beginning with symbiotic relationships in which one prokaryotic cell lived inside of another and both cells benefited from the relationship?

endosymbiont theory

endothermic

heated from within the body

cell wall

inflexible barrieir protecing plant cell

only in animal cell

lysosomes and centrioles

Which are characteristics of prokaryotic cells?

no nucleus or membrane bound organelles

A _ is a specialized membrane-bound structure that carries out a specific cell function.

organelle

Which is a specialized membrane-bound structure that carries out a specific cell function?

organelle

ribosome

organelle that is the site of protein synthesis

centrioles

organelles that occur in piars and are important for cell division

homeostasis

process by which organisms maintain a relatively stable internal environment

cilia

projections from cell surfaces that aid i locomotion and feeding, also used to sweep substances along surfaces.

flagella

projections that aid in locomotion and feeding.

_ cells are defined as cells without a nucleus or other membrane-bound organelles.

prokaryotic

Virchow

proposed that all cells come from pre-existing cells

transport protein

protein that moves substances or wastes through the plasma membrane

Schwann

reported that animal are made up of cells

A _ _ _ directs electrons over the surface of a specimen.

scanning electron microscope

Active transport

the movement of materials through a cell membrane using energy and high concentration