A Level Biology

Front 1

prokaryote

Back 1

microscopic single-celled organism which has neither a distinct nucleus with a membrane nor other specialised organelles, including bacteria

Front 2

What makes prokaryotes simpler than eukaryotes?

Back 2

prokaryotes have no distinct nucleus and no specialised organelles

Front 3

What is the cell wall of bacteria made of?

Back 3

peptidoglycan

Front 4

How big are the ribosomes of bacteria?

Back 4

small

Front 5

What kind of DNA do bacteria cells have?

Back 5

circular

Front 6

Define eukaryote.

Back 6

organism consisting of a cell or cells in which the genetic material is DNA in the from of chromosomes contained in a distinct nucleus

Front 7

How large are the ribosomes of animal cells?

Back 7

larger than bacteria cells

Front 8

Name 2 membrane-bound organelles involved in the processing of proteins in animal cells.

Back 8

endoplasmic reticulum

golgi

Front 9

What are the 3 extra organelles that plant cells have compared to animal cells?

Back 9

cell wall, large vacuole, chloroplasts

Front 10

length of specimen =

Back 10

length of image / magnification

Front 11

What is the magnification of a light microscope based on?

Back 11

the combination of the magnification of the objective lens and the eye piece

(magnifications multiplied together)

Front 12

1cm =__ mm

Back 12

10 mm

Front 13

1mm =__ µm

Back 13

1000 µm

Front 14

1 µm =__ nm

Back 14

1000nm

Front 15

Define resolution.

Back 15

a measure of how easy it is to distinguish between two points that are close together

Front 16

Define diffusion

Back 16

the passive overall movement of particles from an area of high concentration to an area of low concentration

Front 17

Why is facilitated diffusion necessary for some molecules?

Back 17

molecules too large to diffuse across cell membranes need to be helped

Front 18

How are large molecules diffused across cell membranes?

Back 18

they are helped by carrier proteins which change shape to pass molecules through cell membranes

Front 19

Does facilitated diffusion require energy?

Back 19

no

Front 20

How is facilitated diffusion specific?

Back 20

each molecule has its own carrier proteins that allows it through the cell membrane

Front 21

Define osmosis

Back 21

diffusion of water molecules from high to low concentration across a partially permeable membrane

Front 22

Define active transport

Back 22

using energy to transport substances from low to high concentration