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Flashcards in 9 - Use of Biological Resources Deck (41)
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1

Describe how to artificially create ideal conditions for photosynthesis

- Greenhouses trap in heat to keep plants warm (farmers can also use heaters)
- Farmers can increase the amount of CO2 by using a paraffin heater
- This increases the amount of photosynthesis for the plants so the crop yields will be higher

2

How do farmers give plants enough nutrients?

By using fertilisers

3

Why is pest control useful?

- Stops pests from eating plants
- Pesticides (chemical) can be poisonous to humans too and kill other wildlife too
- Biological control is using another organism to prey on the pests
- Biological control can have longer lasting effects as the new organisms can adapt and become pests themselves or kill too many organisms (e.g. cane toads in Australia)

4

Describe the process of making yoghurt

- Sterilise equipment
- Pasteurise the milk (72*C for 15 seconds) to kill any microorganisms
- Lactobacillus bacteria is added and the mixture is incubated (40*C) in a fermenter
- The bacteria ferment the lactose sugar in the milk to form lactic acid causing the milk to clot and solidify to yoghurt
- Flavours are often added

5

What is fermentation?

When microorganisms break sugars down to release energy - usually by anaerobic respiration

6

How are microorganisms grown?

- In fermenters
- Can be used to make penicillin or insulin

7

How do fermenters work?

- Nutrients needed by the microorganisms for growth are provided in the liquid culture medium
- The pH is monitored and kept at the optimum level for the enzymes
- Temperature is kept at the optimum temperature
- Vessels are sterilised between uses with superheated steam that kills unwanted microbes. having aseptic conditions increases the yield

8

Why is it good to have aseptic conditions?

Having aseptic conditions increases the yield of the product as the organisms aren't competing with other organisms. It also means the product is not contaminated

9

How do fermenters work?

- Nutrients needed by the microorganisms for growth are provided in the liquid culture medium
- The pH is monitored and kept at the optimum level for the enzymes
- Temperature is kept at the optimum temperature
- Vessels are sterilised between uses with superheated steam that kills unwanted microbes
- Oxygen for respiration can be added by pumping sterile air
- Microorganisms are kept in contact with fresh medium by paddles that circulate the medium around the vessels so there is equal access to the nutrients

10

Why is it good to have aseptic conditions?

Having aseptic conditions increases the yield of the product as the organisms aren't competing with other organisms. It also means the product is not contaminated

11

Describe how to make beer

- Made from grain (usually barley)
- Allow to germinate for a few days so the starch in the grains is broken down into sugar by enzymes
- The grains are dried in a kiln (called malting)
- The malted grain is mashed up and water is added to produce a sugary solution with lots of bits and is then sieved
- Hops are added to give a bitter flavour
- Yeast is added

12

Describe how to make beer

- Made from grain (usually barley)
- Allow to germinate for a few days so the starch in the grains is broken down into sugar by enzymes
- The grains are dried in a kiln (called malting)
- The malted grain is mashed up and water is added to produce a sugary solution with lots of bits and is then sieved
- Hops are added to give a bitter flavour
- Yeast is added and the mixture is incubated
- The yeast ferments the sugar into alcohol
- The rising concentration of alcohol in the fermentation mixture due to anaerobic respiration eventually kills the yeast which slows down fermentation
- The beer is drawn off through a tap
- Clarifying agents can be added to remove particles and make it clearer
- The beer is pasteurised to kill any yeast left and so it keeps better
- Beer is sold

13

Describe how to make beer

- Made from grain (usually barley)
- Allow to germinate for a few days so the starch in the grains is broken down into sugar by enzymes
- The grains are dried in a kiln (called malting)
- The malted grain is mashed up and water is added to produce a sugary solution with lots of bits and is then sieved
- Hops are added to give a bitter flavour
- Yeast is added and the mixture is incubated
- The yeast ferments the sugar into alcohol
- The rising concentration of alcohol in the fermentation mixture due to anaerobic respiration eventually kills the yeast which slows down fermentation
- The beer is drawn off through a tap
- Clarifying agents can be added to remove particles and make it clearer
- The beer is pasteurised to kill any yeast left and so it keeps better
- Beer is sold

14

Describe an experiment to show the respiration rate of yeast depending on conditions

- Mix together sugar, yeast and distilled water and add to a test tube
- Attach a bung with a tube leading to a second test tube of water
- Put the yeast tube in a water bath at a certain temperature
- Count how many bubbles are produced in 1 minute
- You could also use a gas syringe
- This can be used to calculate the rate of CO2
- Repeat at different temperatures up until the optimum temperature

15

What is selective breeding?

Mating two organisms with desirable characteristics to increase the chance of the offspring inheriting these characteristics
- Yield
- Health/disease resistance
- Animals = temperament/speed/fertility
- Plants = attractive flowers, nice smells

16

How does selective breeding increase the productivity of cows?

- High meat yield
- Continued over many generations to increase the whole cattle

17

How does selective breeding increase the number of offspring in sheep?

- Female sheep who produce lots of offspring are bred more

18

How does selective breeding increase the crop yield

- e.g. tall wheat plants have good grain yield but are damaged easily by rain and wind
- They are bred with dwarf wheat plants who can resist rain and wind but have a low yield

19

How does selective breeding increase the crop yield

- e.g. tall wheat plants have good grain yield but are damaged easily by rain and wind
- They are bred with dwarf wheat plants who can resist rain and wind but have a low yield

20

Describe how and why fish are farmed in the sea

- The fish are kept in cages in the sea to stop them using as much energy swimming about
- The cage also protects them from preditation
- The fish are fed pellets that are carefully controlled to maximise the amount of energy they get meaning they will grow quicker and bigger
- Young fish are kept in special tanks to make sure as many survive as possible
- Keeping the small fish away from the big fish means they won't be eaten and will have enough food
- Fish kept in gages are more prone to disease and parasites (e.g. sea lice which can be treated with pesticides or biological control of wrasse)
- The fish can be selectively bred to produce less aggressive, faster-growing fish

21

What is intraspecification?

When organisms eat individuals of the same species

22

What are the conditions for farming fish in tanks?

- Water can be monitored for temperature, pH and oxygen level
- Control the amount of food and the right type of food
- Water can be removed and filtered to get rid of waste which keeps it clean for the fish

23

What is the role of a restriction enzyme?

To recognise specific sequences of DNA and cut DNA at these points

24

What is the role of a ligase enzymes?

Used to join two pieces of DNA together

25

What is a recombinant DNA?

Two different bit of DNA stuck together

26

What is genetic engineering?

Moving useful genes from an organism's chromosomes into the cells of another

27

Describe how vectors are used in genetic engineering

-

28

What is a vector?

Something that is used to transfer DNA into a cell
There are two sorts - plasmids and viruses

29

What are plasmids?

Vectors that are small, circular molecules of DNA that can be transferred between bacteria

30

What are viruses?

Vectors that insert DNA into the organism they infect