B6

Question 0

Describe bacteria cells?

Answer 0

• May have Flagellum (whip like tail) for movement
• have a cell wall to maintain shape and stop bacterium from absorbing water and bursting
• have bacterial DNA for cell replication and to control cells activities

Question 1

What are BACTERIA?

Answer 1

• ,microscopic single called organisms .

No true nucleus, mitochondria, chloroplasts or a vacuole

Question 2

How do bacteria reproduce?

Answer 2

• BINARY FISSION - by splitting in two

- reproduce rapidly in the right conditions.

Question 3

Bacteria grow and reproduce very fast, what does this mean?

Answer 3

• diseases spread quickly as conditions inside the human body are ideal for bacterial growth ( warm, moist, food supply)
• food can become contaminated by bacteria and toxic waste produced by bacteria as they feed

Question 4

How do viruses invade a living cell?

Answer 4

1- the virus attaches to a host cell and injects it’s genetic material into the cell

2- it used the cell to make components for a new virus

3- the host cell splits open to release the virus

Question 5

What is yeast?

Answer 5

• a single called fungus

- reproduces asexually by budding

Question 6

What do yeast cells need to reproduce quickly?

Answer 6

• lots of sugar
• optimum heat (40) and PH
• the removal of waste products, such as alcohol, which poison it

Question 7

What are ASEPTIC TECHNIQUES?

Answer 7

The process of growing and transferring bacteria without contaminating the sample by touching or breathing on it and without any loss of microbes to the surroundings

Question 8

How can pathogens enter your body?

Answer 8

• airborne microorganisms enter through nose
• ,contaminated food, through mouth
• injected: insect bites, needles or wounds
• reproductive organs during sex

Question 9

What illness does bacteria cause and how is it transmitted?

Answer 9

• cholera
• and food poisoning
• throughout water
• through food

Question 10

What illness do viruses cause and how is it transmitted?

Answer 10

• influenza through airborne droplets

- chickenpox through contact or airborne

Question 11

What illness does fungi cause and how is it transmitted?

Answer 11

• athletes foot through direct contact

Question 12

What is CARBOLIC ACID?

Answer 12

• an antiseptic which kills bacteria

Question 13

How is yogurt made?

Answer 13

1- the equipment is sterilised to kill pathogens

2- raw milk is heated to 80 to kill bacteria and then quickly cooled

3- live bacterial culture is added to the milk

4- the bacteria reproduce and feed on the lactose sugar producing lactic acid, which gives a sharp taste to the yoghurt and thickens and preserves it

5- it is sampled

6- flavours and colours added

Question 14

What is fermentation?

Answer 14

• anaerobic respiration in yeast.
• produces alcohol
• sugars are broken down by yeast in the absence of oxygen to produce alcohol.
• different fruits and seeds are used to provide sugar and flavour
• carbon dioxide is also produced

Question 15

How is beer brewed?

Answer 15

1- extracting sugar: barley seeds are mixed with water and allowed to sprout, turning the starch in the seeds into sugars

2- hops are added for flavour

3- yeast is added to ferment the sugars into alcohol.

4- tank is sealed so that the yeast cabs respire anaerobic ally producing alcohol

5 - chemical added to make the yeast settle leaving a clear liquid

6- the beer is pasteurised to kill harmful microorganisms

7 beer is bottles

Question 16

How is distillation of alcoholic drinks done?

Answer 16

1- the liquid is heated to evaporate the alcohol

2- the concentrated alcohol is trapped and cooled back into a liquid

Question 17

Name the types of biogas?

Answer 17

• methane
• ,carbon dioxide
• traces of hydrogen nitrogen and hydrogen sulfide