1.2 ultrastructure of cells

Question 1

resolution (microscope)

Answer 1

the ability to distinguish two adjacent objects as separate and distinct

Question 2

compartmentalization

Answer 2

dividing the cytoplasm into membrane-bound organelles

Question 3

centriole

Answer 3

a small cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division

Question 4

palisade mesophyll

Answer 4

a layer of the leaf adapted to absorb light efficiently; the cells are packed with many chloroplasts used in photosynthesis

Question 5

capsule

Answer 5

a structure that surrounds the outer cell membrane of certain bacteria and viruses; it serves as a protective tool for the organism

Question 6

cytoplasm

Answer 6

a jellylike fluid inside the cell in which the organelles are suspended, all metabolic and catabolic reactions within the cells occur there

Question 7

vacuole

Answer 7

a large specialized vesicle within the cytoplasm of a plant cell, enclosed by a membrane and typically containing fluid

Question 8

endoplasmic reticulum

Answer 8

a network of membranous tubules within the cytoplasm; it usually has ribosomes attached and is involved in protein and lipid synthesis

Question 9

plasmodesmata

Answer 9

a narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells and allows communication between them

Question 10

intracellular

Answer 10

any materials or structures found inside the cell membrane or wall

Question 11

chitin

Answer 11

a fibrous substance consisting of polysaccharides and forming the major constituent in the exoskeleton of arthropods and the cell walls of fungi

Question 12

nucleoid

Answer 12

region of prokaryotic cells where DNA is located

Question 13

nucleus

Answer 13

an organelle surrounded by a double membrane that contains DNA

Question 14

plasmid

Answer 14

typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan

Question 15

pili

Answer 15

structure on the surface of prokaryotes used to attach to each other and other surfaces

Question 16

light microscope

Answer 16

a microscope that uses a beam of light passing through one or more lenses to magnify an object

Question 17

plasma membrane

Answer 17

a membrane of lipids and proteins which forms the external boundary of the cytoplasm of a cell or encloses a vacuole, and regulates the passage of molecules in and out of the cytoplasm

Question 18

archaea

Answer 18

similar to bacteria in size and structure but radically different in molecular organization; believed to constitute an ancient intermediate group between the bacteria and eukaryotes

Question 19

mitochondria

Answer 19

a membrane-bound organelle in eukaryotic cells; the site of aerobic respiration (cellular)

Question 20

ribosome

Answer 20

a cell organelle; the site of protein synthesis

Question 21

cell membrane

Answer 21

a thin membrane around the cytoplasm of a cell

Question 22

cellulose

Answer 22

an insoluble substance that is the main constituent of plant cell walls

Question 23

protist

Answer 23

a single-celled organism such as a protozoan or simple algae

Question 24

electron microscope

Answer 24

microscope that forms an image by focusing beams of electrons onto a specimen

Question 25

cholesterol

Answer 25

a component of the cell membrane, that depending on temperature, supports or inhibits fluidity

Question 26

fungi

Answer 26

a group of spore-producing organisms feeding on organic matter, including molds, yeast, mushrooms, and toadstools

Question 27

lysosome

Answer 27

a small organelle present in the cytoplasm of many cells, which contains enzymes needed for metabolism, lighter in colour than vesicles

Question 28

cell wall

Answer 28

a rigid layer of non-living material that surrounds the cells of plants and prokaryotes

Question 29

vesicle

Answer 29

sac like organelles that transport materials within and outside of the cells, very dark in colour

Question 30

ultrastructure

Answer 30

the detailed structure of the internal components of cells as revealed by the electron microscope

Question 31

peroxisomes

Answer 31

an organelle in the cytoplasm of eukaryotic cells containing digestive enzymes enclosed in a membrane,, very dark in colour

Question 32

bacteria

Answer 32

unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease

Question 33

extracellular

Answer 33

any materials or structures found outside the cell membrane or wall

Question 34

chloroplast

Answer 34

a membrane-bound organelle containing chlorophyll for photosynthesis

Question 35

flagella

Answer 35

a long, whip-like filament that helps in cell mobility; many prokaryotes have flagella