6.2.1 cloning and biotechnology

Question 1

what is a clone

Answer 1

genetically identical organism or cell

Question 2

examples of natural cloning in plants

Answer 2

• runners - strawberry
• rhizomes - ginger
• tubers - potato
• bulbs - onions

Question 3

how to take a cutting

Answer 3

• cut plant between nodes - scalpel - 45 degrees
• dip into rooting powder (auxin)
• put in moist soil
• leave in humid conditions (cover with plastic bag)
• wait until roots develop

Question 4

why do you have to keep plants in humid conditions when taking cuttings

Answer 4

reduce transpiration rate

Question 5

process of micropropogation

Answer 5

• sterile scalpel/forceps - cut leaf into small pieces
• transfer explant to sterile nutrient agar
• divides into callus
• using root and shoot stimulating hormones
• develops into plantlets
• transfer to soil for growth

Question 6

pros of micropropogation

Answer 6

• fast prod. of genetically identical plants
• can clone to make rare or endangered species
• make seedless plants

Question 6

cons of microporopagation

Answer 6

• expensive
• no genetic variation - vulnerable to disease
• contamination
• labour intensive

Question 7

example of natural cloning in animals

Answer 7

identical twins
- zygote splits

Question 8

process of SCNT

Answer 8

somatic cell nuclear transfer
- take a somatic cell from sheep (udder)
- remove nucleus from somatic cell
- enucleation of egg donor’s egg
- somatic cell nucleus inserted into enucleated egg
- electric shock - to fuse + stimulate division
- implant to surrogate mother - clone produced

Question 9

pros of SCNT

Answer 9

• high yield livestock
• save endangered species
• for medicine

Question 10

cons of SCNT

Answer 10

• expensive
• health issues in clones
• reduces genetic diversity

Question 11

enucleation definition

Answer 11

removing nucleus from cell

Question 12

what is therapeutic cloning

Answer 12

• cloning of human cells for medical purposes
• growing tissues or organs for transplant

Question 13

why use microorganisms in biotechnology?

Answer 13

• short life cycles - fast reproduction
• less energy and little labour
• food production
• medicine - antibiotics
• treatment of waste

Question 14

examples of biotechnological uses

Answer 14

• penicillium mold - produces penicillin
• yeast - makes bread and beer
• lactic acid + bacteria - make yogurt and cheese
• fungi - mycoprotein - quorn

Question 15

advantages of microorganisms in food production

Answer 15

• high protein content esp in fungi
• less land required - reduces impact to the land
• grow in controlled environments so climate change has no effect

Question 16

disadvantage of microorganism in food

Answer 16

• people might find it unappetising because of taste and texture
• contamination of cultures mean it becomes toxic

Question 17

how to use aseptic techniques

Answer 17

• disinfect surfaces using alcohol based disifectants
• pass inoculating loops through flame to sterilize
• sterile equipment - sterile agar plates/broth
• keep petri dish lids closed

Question 18

describe batch fermentation

Answer 18

• closed system - nutrients added at start
• fermentation stops when nutrients are depleted
• used for penicillin and enzymes

Question 19

describe continuous fermentation

Answer 19

• open system - nutrients continuously added
• allow constant productions
• used for yeast in brewing

Question 20

factors that affect yield

Answer 20

• pH
• temp
• oxygen levels
• nutrient supply

Question 21

describe what happens in the growth curve

Answer 21

• lag phase - cells are adjusting to environment - slow growth
• log phase - exponential - rapid cell division
• stationary phase - growth=death rate
• death phase - nutrients run out, waste accumulates - death

Question 22

microbial growth formula

Answer 22

N = N0 x 2^n
N = final population size
N0 = initial population size
n= number of generations

Question 23

aerobic Vs anaerobic fermentation

Answer 23

aerobic
- more ATP
- higher yield of products
- e.g penicillin

anaerobic
- less ATP
- used in beer - yeast respire anaerobically

Question 24

what are immbolised enzymes

Answer 24

enzymes that is fixed in a material so it does not mix freely with the reaction mixture

Question 25

why use immobolised enzymes

Answer 25

- don't denature easily - reusable - can be separated easier - no contamination with the final product

Question 26

describe and evaluate using adsorption

Answer 26

- enzymes attach to a surface e.g clay with ionic/hydrophobic interactions Pro - cheap, easy Cons - enzymes detach easily

Question 27

describe and evaluate covalent bonding

Answer 27

- enzymes are covalently bonded to a surface e.g clay Pros - strong attachment = no enzyme leakage Cons can reduce enzyme activity if binding site is affected

Question 28

describe and evaluate entrapment

Answer 28

- enzymes trapped in a gel e.g silica Pros - protects enzymes Cons - substrates can diffuse out = slower ROR

Question 29

describe and evaluate membrane encapsulation

Answer 29

- enzymes are enclosed in a semi-permeable membrane Pros - seperates enzyme from mixture Cons - diffusion can limit speed or reaction

Question 30

industrial use of immobolised enzymes

Answer 30

- HFCS - high fructose corn syrup - lactose free dairy - starch breakdown

Question 31

disadvantages of immobolised enzymes

Answer 31

- setting up immobolised enzymes is expensive - slower beacause they are less active than free enzymes