Cloning and Biotechnology

Question 1

what is vegetative propagation

Answer 1

Vegetative propagation is a type of asexual reproduction that produces progeny by any vegetative propagule (rhizome, tubers, suckers etc.) without gamete formation and fertilization of male and female gametes
»>produces clones/identical
surviving adverse conditions

Question 2

name some examples of vegetative propogation

Answer 2

> > stolons- side runners (peg down)
runners- similar to stolons
rhizomes-underground (ginger) pull stem up from underground but any rhizomes left under soil will grow plant again
underground stems- for food storage and reproduction eg)tubers from potato store starch for energy but also can be replanted, bulbs, rhizomes, corms

look up pics of all

Question 3

what are cuttings and how carried out

Answer 3

take a side shoot (which can eb dipped in rooting powder auxins) and planted into compost and grown. placed plastic bag on top to reduce water loss by excess transpiration

can create open wound for infection in parent

Question 4

What is grafting? how is it done

Answer 4

graft top part (scion) with one chosen characteristic onto a bottom part (root stock) and wrap and wax to prevent infection and plant will have characteristic of both plants

-eg many apples on one tree of different varieties

Question 5

what is layering in plants

Answer 5

using peg and stake

The development of roots on a stem while the stem is still attached to the parent plant is called layering. A layer is the rooted stem following detachment (removal) from the parent plant. Some plants propagate naturally by layering, but sometimes plant propagators assist the process.

Question 6

which tissue of a plant is used in a tissue culture

Answer 6

meristematic tissue- constantly dividing undifferentiated cells that can become any cell

Question 7

what is tissue culture

Answer 7

aka micropropagation
-cells from meristematic tissue placed on agar plate
-any wool placed on top allows air in for respiring but stops infection
-produces multiple embryos all identical
plantlets are placed in soi

Question 8

step by step of how tissue culture is carried out

Answer 8

> meristematic tissue taken shoot tip/bud
sterile conditions + sample sterilised
explant placed in sterile culture medium with plant growth hormones such as auxins+cytokinins
mitosis stimulated
cells proliferated - callus formed (mass of identical cells)
callus divided up with forceps- nurtients+hormones produced- differentiation occurs
plantlets form
plantlets potted into compost-grow in greenhouse and harden off
new plant for selling

Question 9

advantages of tissue culture/plant cloning

Answer 9

-rapid production of large number plants
-known genetic makeup
-disease free/resistant
high yield
-control time of year plants are produced by precisly controlling conditions
-seedless plants/sterile proudced
-overcome problem of growing difficult plants from seeds eg orchid

Question 10

disadvantages of tissue culture/plant cloning

Answer 10

• all plants have same genetic information so are vulnerable to same disease/ pest
• no new beneficial characteristics will arise as they do by chance naturally (natural selection doesn’t occur)
• no variation means gene pool reduced

Question 11

what are natural cloning examples in animals

Answer 11

binary fission-splitting apart similar in concept to the mitosis that happens in multicellular organisms
budding-hydra - regrowing heads buds grow on sides of body that develop into genetically identical clones
fragmentation-starfish arm regenerates into new organism

Question 12

describe difference in reproduction in aphids in seasons

Answer 12

-sexual in autumn and winter
asexual in pathenogenetic female colonies
»>interspecific competition dominates and rapid reprouduction phase is advantageous

Question 13

how are identical twins formed

Monozygotic

Answer 13

cleavage furrow of fertilised ovum to produce two separate embryos
one sperm and one egg fertilised and undergo mitosis if zygote splits in two they are identical
»shared placenta

Question 14

how are dizygotic twins formed

Answer 14

2 dif sperm and 2 dif egg genetically distinct

|&raquo_space;separate placenta

Question 15

how is arteficial embryo splitting carried out

Answer 15

> > high value pedigree animals used as egg and sperm donors eg cattle and sheep
cells from early embryo are separated
each cell can potentially grow into an individual but all will be genetically identical clones

Question 16

how is an identical clone produced in a pig

Answer 16

1>cells from animal are stored in lab to prevent growth/division
2>the nucleus is extracted from donor cell and fused with an empty egg cell with no nucleus
»»>which came from the unfertilised egg that has had nucleus removed from a sow (which will be the surrogate)
3>fused cells begins dividing normally and matures for a few days
4>embryo placed in uterus of surrogate mother
5> animal born has same DNA as donor animal

Question 17

pros of animal cloning

Answer 17

• multiplication of animals
• recovery of endangered species
• production of transgenic animals
• replicate animals for research
• produce animals w/ desirable traits
• solution to infertility

Question 18

cons of animal cloning

Answer 18

• undermines concept of reproduction and family
• playing god
• weakens diversity and ability of adaption
• ethical and moral principles
• concerns about eugenics
• confuses personal identity of clone and psychological development of clone

Question 19

how was dolly the sheep made

Answer 19

> donor cell taken from sheeps udder with nucleus and egg cell taken from an adult female sheep and nucleus removed so it is ennucleated
these are fused through a process such as electrofusion
the fused cell begins dividing normally
embryo is placed in uterus of surrogate mother
embryo develops into a clone of the sheep who gave the donor nucleus

Question 20

name 3 advantages of vegetative propagation in agriculture

Answer 20

• higher crop field in a shorter/quicker amount of time
• plants can be grown any time of year regardless of season
• easier to harvest

Question 21

where is the tissue that is removed coming from for plant clones

what is this tissue sample called

Answer 21

meristematic tissue from axial buds or shoot tips

sample called a explant

Question 22

what is used to sterilise the plant when preparing to clone

hormones stimulate mitosis which forms a mass of cells called:

Answer 22

ethanol

Callus

Question 23

compare the equipment and techniques of cuttings with those used for micropropagation

Answer 23

cutting needs less expensive equipment

micropropagation needs more skilled people to do it

Question 24

what are the advantages of using yeast for biotechnology

Answer 24

no welfare issues involved

• large range of availability and fungi/bacteria
• cheap nutrients
• short life cycle/ but reproduce rapidly
• no rules on genetic engineering
• all they need is food source, low temps and oxygen

Question 25

Name some aseptic techniques

Answer 25

> autoclave to sterilise equipment or oven to heat
antisepic hand hygiene, alcohol
sterile gloves, sterile drapes, sterile masks, protective wrappers
sterile nutrients, can sterilise air with UV
lid or wool stopper
limit entry to aseptic field/ one person
sterilise inoculating loop

Question 26

what is indirect food production

Answer 26

microbe acting on other foods eg) yeast on bread/cheese/yogurt

Question 27

what is direct food production

Answer 27

you eat the microbe itself eg Quorn

Question 28

describe components making up a fermenter

Answer 28

> impellars - keep movement inside reactor so no microbes sink and all get oxygen
harvest line lets out microbes
vent lets out CO2 waste product this stops pessure building
air filter stops microbes getting in
yeast sterilised with steam
controlled temps and pH so enzymes at optimum temp
cold water can be passed through bottom

Question 29

describe what a batch fermenter is

Answer 29

> ‘closed system’ nutrients only added at start and product removed at end
easy to set up and maintain so most used method of fermentation
quality between batches differs but if goes wrong only one batch effected eg) contamination
can create different batches
product of growth is either biomass/metabolites
pressure steam wash to sterilise

Question 30

describe what a continuous fermenter

Answer 30

> exponential growth of microbes is maintained in fermented for prolonged periods
addition of fresh nutrients and continues until vessel full and product continuously removed
consistent quality
contamination effects all
high productivity
maintain optimum growth environment

Question 31

what is one advantage and disadvantage of using clones to test a treatment for a disease

Answer 31

+ genetically identical so all react the same

-clone could have unknown health problem

Question 32

what are potential applications of adult cell cloning

Answer 32

> recovery of endangered species
produce high value pedigree animals with desireable characteristics
investigate treatment of disease

Question 33

what is SCNT

Answer 33

somatic cell nuclear fusion

this is like dolly the sheep uses electrofusion

Question 34

what 3 factors should be taken into acount when comparing SCNT among different animal

Answer 34

> same stage of development of surrogate mother
general health of all surrogates and mothers
conditions surrogates kept in
number of eggs inseminated in each surrogate mother

Question 35

which reasons could mean that dolly didnt die due to the age of donor nucleus

Answer 35

> dolly was individual so health problems could be unrelated to cloning
might be different between animals

Question 36

what are the phases of the growth of microbes according to the numbers of bacteria against/ time graph
4 stages

Answer 36

lag phase
log/exponential growth phase
stationary phase
death/ logarithmic decline phase

Question 37

what happens during the lag phase

Answer 37

slow growth
no. deaths = no. births
beginning to synthesise enzymes to break down nutrient (settling in)

Question 38

what happens during the log/ exponential growth phase

Answer 38

> faster growth rate than any other time
population increases exponentially
birth> death

continuous fermentation held here

Question 39

what happens during the stationary phase

why might this be happening?

Answer 39

birth= death rate
>nutrients such as oxygen may be running out so less growth
>intraspecific competition (can’t distiguish between bacteria and each other)
>toxic build up of waste products
>temp going up

Question 40

what happens during the death/ logarithmic decline phase

Answer 40

death> birth rate
> population goes down
> limitting factors could have increased to point where death rate exceeds birth

Question 41

what are the two types of cell counting and examples of each

Answer 41

DIRECT CELL COUNT

• counting chambers
• electronic counters
• on membrane filters