Unit 4

Question 1

light microscope

Answer 1

visible light is passed through a specimen and then through a glass lenses

Question 2

magnification

Answer 2

the ratio of an object’s image size to its real size

Question 3

resolution

Answer 3

the measure of the clarity of the image, or the minimum

Question 4

contrast

Answer 4

the difference in brightness between the light and dark areas of the image

Question 5

scanning electron microscope (SEM)

Answer 5

focuses a beam of electrons onto the surface of a specimen, produces 3d images

Question 6

transmission electron microscope (TEM)

Answer 6

focus a beam of electrons through a specimen

Question 7

cell fractionation

Answer 7

breaks ups cells and separates the components using centrifugation

Question 8

plasma membrane

Answer 8

a selective barrier that allows the passage of oxygen nutrients

Question 9

nucleus

Answer 9

contains the cell’s genes

Question 10

nuclear envelope

Answer 10

encloses the nucleus separating it from the cytoplasm

Question 11

nuclear lamina

Answer 11

the shape of the nucleus, composed of protein filaments

Question 12

chromosomes

Answer 12

DNA organized into units

Question 13

chromatin

Answer 13

the DNA and protein of chromosomes together

Question 14

nucleolus

Answer 14

located within the nucleus and is the site of ribosomal RNA synthesis

Question 15

ribosomes

Answer 15

complexes of ribosomal RNA and protein

Question 16

endomembrane system

Answer 16

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, plasma membrane

Question 17

Endoplasmic reticulum

Answer 17

more than half of the total membrane in many eukaryotic cells

Question 18

rough ER

Answer 18

has bound ribosomes that secrete glycoproteins, distribute transport vesicles, the membrane factory for the cell

Question 19

smooth ER

Answer 19

synthesize lipids, metabolizes carbs, detoxifies drugs and poisons, stores calcium ions

Question 20

golgi apparatus

Answer 20

flattened membranous sacs(cisternae), modified products of the ER, manufactures certain macromolecules, sorts and packages into transport vesicles

Question 21

lysosomes

Answer 21

a membranous sac of hydrolytic enzymes that can digest macromolecules

Question 22

phagocytosis

Answer 22

cells that can engulf another cell, which forms a food vacuole

Question 23

autophagy

Answer 23

the process of reusing old and damaged cell parts

Question 24

contractile vacuoles

Answer 24

found in many freshwater protists, pump excess water out of cells

Question 25

central vacuoles

Answer 25

found in many mature plant cells, a repository for inorganic ions(K+ & Cl)

Question 26

mitochondria

Answer 26

the site of cellular respiration, a metabolic process that uses oxygen to generate ATP

Question 27

chloroplasts

Answer 27

found in plants and algae, the sites of photosynthesis

Question 28

peroxisomes

Answer 28

a organelle that generates hydrogen peroxide, destroys the excess

Question 29

endosymbiont theory

Answer 29

the theory that some organelles in eukaryotic cells and once were prokaryotic microbes

Question 30

cytoskeleton

Answer 30

the network of fibers extended throughout the cytoplasm, helps support the cell and maintain the shape

Question 31

microtubules

Answer 31

thickest component of the cytoskeleton, responsible in the movement of organelles and separate chromosomes during cell division

Question 32

microfilaments
(actin filaments)

Answer 32

the thinnest components of cytoskeleton, responsible in changes of the cell shape, muscle contraction, cell division

Question 33

intermediate filaments

Answer 33

middle range component of the cytoskeleton, and anchors of nucleus and certain organelles, forms the nuclear lamina

Question 34

cell wall

Answer 34

extracellular structure that distinguishes plant cells from animal cells

Question 35

extracellular matrix (ECM)

Answer 35

made up of glycoproeteins like collagen, proteoglycans, and fibronectin

Question 36

integrin

Answer 36

ECM proteins that bind to