B1a - cell structure and microscopy fact test

Question 1

features of a eukaryotic cell

Answer 1

• have a nucleus
• bigger than prokaryotic cells

Question 2

features of a prokaryotic cell

Answer 2

• don’t have a nucleus, instead have DNA loops and plasmids (rings of DNA)
• smaller than eukaryotic cells

Question 3

function of a nucleus

Answer 3

contains genetic material and controls activities of the cell

Question 4

function of cytoplasm

Answer 4

where most of the chemical reactions happen

Question 5

function of cell membrane

Answer 5

controls what enters and leaves the cell

Question 6

function of mitochondria

Answer 6

where most of the reactions of aerobic respiration happen

Question 7

function of ribosomes

Answer 7

where proteins are made in the cell/site of protein synthesis

Question 8

function of cell wall (in plants)

Answer 8

• made of cellulose
• rigid to provide structure and protection
• stops cell from bursting if water pressure increases

Question 9

function of permanent vacuole (in plants)

Answer 9

• contains cell sap
• stores the nutrients of the cell

Question 10

function of chloroplasts (in plants)

Answer 10

• contains chlorophyll
• absorbs light for photosynthesis

Question 11

function of DNA loop (in bacteria cells)

Answer 11

contains genetic material

Question 12

function of plasmids (rings of DNA in bacteria cells)

Answer 12

can move from one bacteria to another

Question 13

function of flagellum (in bacteria cells)

Answer 13

rotate or move in a whip-like motion to help the cell move

Question 14

pros of light microscopes

Answer 14

• easy to use
• relatively cheap
• can use live or dead specimen
• can easily use coloured dyes

Question 15

cons of light microscopes

Answer 15

resolution is limited to 0.2 micrometers meaning you cannot see sub-cellular structures

Question 16

pros of electron microscopes

Answer 16

has a higher resolution meaning you can see sub-cellular structures

Question 17

cons of electron microscopes

Answer 17

• takes a long time to prepare specimen
• specimen must be dead
• image is only in black and white
• very expensive

Question 18

what is an image

Answer 18

the image we see when looking down on the microscope

Question 19

what is an object

Answer 19

the sample you are looking at

Question 20

what is resolution

Answer 20

the ability to distinguish objects from each other (how clear the image)

Question 21

what is magnification

Answer 21

how many times bigger the image is compared to the object

Question 22

what is the magnification equation

Answer 22

magnification = image size / actual size

Question 23

how is a sperm cell adapted to its function

Answer 23

• acrosome to break enzymes on outer layer of egg
• nucleus with 1/2 as much genetic material to join with the egg
• lots of mitochondria to release energy to move
• flagellum to help the cell move

Question 24

how is a nerve cell adapted to its function

Answer 24

• axon carries nerve impulses
• myelin sheath for insulation so impulses can move quicker
• dendrites for connections to other neurons

Question 25

how is a muscle cell adapted to its function

Answer 25

• mitochondria to transfer energy which is needed to contract and relax
• can store glycogen to be used in respiration
• proteins that contract

Question 26

how is a root hair cell adapted to its function

Answer 26

• large permanent vacuole to speed up osmosis
• thin walls to not restrict the movement of water
• increased surface are for water to move
• mitochondria to transfer energy for respiration

Question 27

how is a xylem cell adapted to its function

Answer 27

• cells die and form long hollow tubes to allow water and mineral ions to move easily
• chemical called lignin builds up in spirals, makes the cell very strong to withstand pressure and supports the stem

Question 28

how is a phloem cell adapted to its function

Answer 28

• cell walls between cells break down to form sieve plates to allow water and dissolved food the move
• sieve plates are accompanied by companion cells which transfer energy to move food up and down