biology topic 1

Question 1

what is a microscope used for

Answer 1

to magnify small objects that would otherwise not be visible with the eye

Question 2

What organelles are in animal cells

Answer 2

mitochondria, cytoplasm, nucleus, cell membrane

Question 3

What organelles are in plant cells

Answer 3

chloroplasts, vacuole, cell membrane, cytoplasm, nucleus, cell wall, mitochondria

Question 4

what does the nucleus do

Answer 4

controls the cell activities and contains genetic material (DNA)

Question 5

What are eukaryotic cells

Answer 5

-contain genetic material within their nucleus
-the organelles are contained within membranes
- usually contain mitochondria
-contain ribosomes
-example- plant and animal cells

Question 6

what are prokaryotic cells

Answer 6

-don’t contain membrane bound organelles
-much smaller than eukaryotic cells
-contain genetic material in small rings called plasmids in the cytoplasm
-contain ribosomes which make proteins for the cell
-example-bacteria

Question 7

what does culture mean in science

Answer 7

to grow microorganisms (such as bacteria) for scientific study

Question 8

What is commonly used to produce cultures of bacteria and other microorganisms

Answer 8

Petri dishes which contain a nutrient jelly called agar

Question 9

How do you do aseptic technique

Answer 9

clean hands and workspace, light Bunsen burner and open it up to a blue flame which will sterilise the air around your workspace, pass an inoculating loop through the Bunsen flame to sterilise it, open the vial of sterilised water and pass the rim through the Bunsen flame, dip the inoculating loop into the sterilised water then reseal the vial, draw a Z shape on the agar plate with the inoculating loop then replace the lid, pass the loop through the flame again, use tape to secure lid (not completely around as it will make it airtight and oxygen won’t reach it) and incubate the plate for 48 hours at 25C (room temp)

Question 10

What is the aseptic technique used for

Answer 10

to avoid contamination of equipment and allow an organism to be investigated at a time

Question 11

What is a pathogen

Answer 11

bacteria that cause disease. Bacteria are able to divide and multiply rapidly which is why they can cause diseases

Question 12

how do you calculate the final no. of bacteria

Answer 12

final no. of bacteria= initial no. of bacteria (always one)*2^number of divisions

Question 13

how do you calculate magnification

Answer 13

magnification= size of image/ actual size of object

Question 14

how many micrometres (μm) are in a millimetre?

Answer 14

1000

Question 15

what does a ribosome do?

Answer 15

creates proteins for the cell

Question 16

What does the nucleus do

Answer 16

controls cell activities and contains genetic material (DNA)

Question 17

What is the cytoplasm

Answer 17

jelly like substance where chemical reactions occur

Question 18

What does the cell membrane do

Answer 18

controls substances that enter and leave the cell

Question 19

What do the chloroplasts do

Answer 19

contain chlorophyll which absorb sunlight for photosynthesis

Question 20

What does the mitochondria do

Answer 20

site of aerobic respiration, contains lots of energy

Question 21

What does the vacuole do

Answer 21

contains liquid that stores substances for the cell and keeps it rigid

Question 22

what does the cell wall do

Answer 22

surrounds plants cells and provides strength and support

Question 23

describe steps to view a cell sample under a light microscope

Answer 23

-select lowest power on objective lens
-turn coarse focus wheel until you can see the cells
-turn fine focus wheel until cells are in focus and you can see them clearly

Question 24

why is it important to sterilise the culture medium and all the apparatus before use

Answer 24

to kill microorganisms/ prevent contamination

Question 25

why shouldn’t the petri dish be incubated at a higher temperature than 25 degrees celscius

Answer 25

to prevent the growth of pathogens

Question 26

sperm cell function and adaptations

Answer 26

function- fertilize egg during reproduction
adaptations- tail, mitochondria for energy

Question 27

neuron (nerve cell) function and adaptations

Answer 27

function- transmit signals or impulses throughout the body
adaptations- long fibre (axon) to carry messages and dendrites to receive messages from other cells

Question 28

leaf cell function and adaptations

Answer 28

function- responsible for photosynthesis
adaptations- chloroplasts

Question 29

root hair cell function and adaptations-

Answer 29

function- absorb water, minerals and nutrients to be sent throughout the plant
adaptations- large surface area to increase rate of absorption