Topic 3: Microscopes & Eukaryotes

Question 1

Light microscope

Answer 1

a tool that uses a beam of light and optical lenses to magnify specimens up to 1500 times life size

Question 2

Magnification

Answer 2

a measure of how much bigger the image you see is than the real object

Question 3

Electron microscope

Answer 3

a tool that uses a beam of electrons and magnetic lenses to magnify specimens up to 500 000 times life size

Question 4

Resolution

Answer 4

a measure of how far apart two objects must be before they are seen as separate entities

Question 5

Transmission electron micrographs (TEMs)

Answer 5

micrographs produced by the electron microscope that give 2D images magnified up to 500 000 times

Question 6

Scanning electron micrographs (SEMs)

Answer 6

micrographs produced by the electron microscope that have a lower magnification than TEMs, but produce a 3D image

Question 7

Cytoplasm

Answer 7

a jelly-like liquid that makes up the bulk of the cell and contains the organelles

Question 8

Nucleus

Answer 8

an organelle containing the genetic material, as well as protein, surrounded by a double nuclear membrane with pores

Question 9

Protoplasm

Answer 9

the cytoplasm and nucleus combined

Question 10

Ultrastructure

Answer 10

the detailed organisation of the cell, only visible using the electron microscope

Question 11

Intracellular

Answer 11

inside the cell

Question 12

Chromatin

Answer 12

the granular combination of DNA bonded to protein found in the nucleus when the cell is not actively dividing

Question 13

Nucleolus

Answer 13

A dense region of DNA and protein found in the nucleus; involved in the production of ribosomes and control of growth and division

Question 14

Mitochondria

Answer 14

rod-like structures with inner and outer membranes that are the site of aerobic respiration

Question 15

Cristae

Answer 15

the infoldings of the inner membrane of the mitochondria which provide a large surface area for the reactions of aerobic respiration

Question 16

Centrioles

Answer 16

bundles of tubules found near the nucleus and involved in cell division by the production of a spindle of microtubules that move the chromosomes to the ends of the cell

Question 17

Spindle

Answer 17

a set of overlapping protein microtubules running the length of the cell, formed as the centrioles pull apart in mitosis and meiosis

Question 18

80S ribosomes

Answer 18

the main type of ribosome found in eukaryotic cells, consisting of ribosomal RNA and protein, made up of a 60S and 40S subunit

Question 19

70S ribosomes

Answer 19

the ribosomes found in the mitochondria and chloroplasts of eukaryotic cells and in prokaryotic organisms

Question 20

Endosymbiotic theory

Answer 20

a theory that suggests mitochondria and chloroplasts originated as independent prokaryotic organisms that began living symbiotically inside other cells as endosymbionts

Question 21

Lysosomes

Answer 21

organelles full of digestive enzymes used to break down worn-out cells or organelles or digest food in simple organisms

Question 22

Apoptosis (programmed cell death)

Answer 22

the breakdown of worn-out, damaged or diseased cells by the lysosomes

Question 23

Endoplasmic reticulum (ER)

Answer 23

A network of membrane-bound cavities in the cytoplasm, connected to the nuclear membrane, involved in cellular transport and the synthesis of substances.

Question 24

Rough endoplasmic reticulum (RER)

Answer 24

endoplasmic reticulum that is covered in 80S ribosomes and which is involved in the production and transport of proteins

Question 25

Exocytosis

Answer 25

the movement of large molecules out of cells by the fusing of a vesicle containing the molecules with the surface cell membrane, requiring ATP

Question 26

Smooth endoplasmic reticulum (SER)

Answer 26

a smooth tubular structure which is involved in the synthesis and transport of steroids and lipids in the cell

Question 27

Golgi apparatus

Answer 27

stacks of membranes that modify proteins made elsewhere in the cell and package them into vesicles for transport