W5 5(d) Cloning

Describe the process of micropropagation. (5)

• M1: Use forceps / scalpel / knife (or equivalent) to remove explants / pieces from plant.

• M2: Wash in bleach / hypochlorite / ethanol / alcohol / sterile wipes (or equivalent).

• M3: (Grow on) agar.

• M4: Add nutrients / minerals / carbohydrates / amino acids / named mineral / growth factors / hormones.

• M5: Add acid / alkali / buffer. acid + its salt or vice versa

• M6: Use several / multiple explants / repeat.

• M7: Control temperature / carbon dioxide / light.

• M8: Use sterile agar / sterile tubes.

• M9: Use same age plant / same plant / same size of explants.

• M10: Count number of shoots after same / stated time.

always repeat

State one way to sterilise an explant. (1)

M1: Use bleach / hypochlorite / disinfectant / antiseptic / chlorine OR alcohol / ethanol OR radiation / UV / gamma rays / X-rays.

List the nutrients that should be added to the agar medium. (3)

• M1: Nitrate / ammonium / magnesium / calcium / sulphate / potassium / phosphate / iron.

• M2: Amino acids.

• M3: Sucrose / glucose / fructose / sugar / starch.

micro + macro + sugar

Design an investigation to find out if adding more amino acids to the nutrient media increases the growth of the plants. (6)

• C: Use with and without amino acids / a range of amino acid concentrations / different amino acids.

• O: Use explants of the same age / mass / size / same plant / species / clone.

• R: Repeat the experiment (for each concentration).

• M1: Measure the height / width / mass / number of leaves.

• M2: Measure after a stated time (e.g., 1 day+).

• S1: Control the temperature / light / CO₂ / humidity / oxygen / water.

• S2: Keep conditions sterile / use agar / minerals / glucose / hormones.

explants are a piece of living tissue removed from the body

State two advantages of using micropropagation (tissue culture) to produce plants. (2)

• M1: Lots produced.

• M2: Genetically identical / no variation / all same type / identical / same characteristics / guaranteed plant / they are clones.

• M3: Can grow GM plants (or equivalent).

• M4: Faster / quicker.

• M5: Any time of year.

• M6: Can be used for plants that are hard to germinate / grow from seed.

Describe the stages used to clone a mammal (such as a sheep). (6)

• M1: Use enucleated egg / empty egg / remove nucleus from egg (or equivalent).

• M2: Nucleus from body cell / diploid nucleus (placed into empty egg) / fuse adult cell with empty egg.

• M3: Use of electricity / shock.

• M4: Cell division / mitosis.

• M5: Embryo.

• M6: Uterus / womb.

• M7: Surrogate mother.

Explain why it is better to use a live animal rather than a dead animal for cloning. (2)

• M1: Cells are dead / not alive / inactive / no longer respire.

• M2: Genetic material / chromosomes / gene / allele / DNA (is) destroyed / mutated / damaged / degraded (or equivalent).

NOT denatured

Explain why a clone might behave differently from the cell donor. (2)

• M1: Behaviour not just due to genetic material / chromosomes / gene / allele / DNA.

• M2: Behaviour affected by environment / learning / nurture / training.

in vitro

In vitro means biological processes or experiments carried out outside of a living organism, such as in a test tube, Petri dish, or glass container.