Farmers can use plant cloning to produce new plants by taking cuttings from non-reproductive tissue such as the leaves or stems.

This process is known a vegetative propagation.

Suggest three advantages of vegetative propagation for farmers.

Describe the process of cloning a plant by taking a cutting.

Micropropagation is another method for producing plant clones.

Describe two differences between the equipment and techniques required for vegetative propagation and micropropagation.

Animals can be cloned using a technique known as somatic cell nuclear transfer (SCNT).

The most well-known example of cloning using this technique is the cloning of Dolly the sheep in 1996.

Describe how animals, such as Dolly the sheep, can be cloned using SCNT.

Some farmers use cloning to increase milk production by cattle.

An alternative to this is to allow cows with high milk production to breed with other normal cows.

Give two advantages of cloning cows with high milk production.

Give two disadvantages of cloning cows with high milk production.

SCNT can also be used to clone frogs.

Frogs lay their eggs in water. The eggs then develop and hatch into tadpoles.

Suggest a key difference in the method for cloning a frog and cloning a cow.

Microorganisms can be cultured using either batch or continuous fermentation.

Complete the table below to show whether each statement applies to batch or continuous fermentation.

Write the letter B for batch and the letter C for continuous.

Microorganisms are often responsible for the spoiling of food.

Food preservation methods, including freezing and pickling, can be used to prevent spoilage by microorganisms.

Explain how freezing and pickling work to reduce food spoilage.

Mycoprotein is a type of protein that is made using fungi and is considered to be a healthy alternative to meat.

Describe three advantages of using fungi to produce mycoprotein.

Describe three disadvantages of using fungi to produce mycoprotein.

Lactose is found in many dairy products such as cow's milk. Many humans are lactose intolerant, meaning they cannot digest lactose.

Cow's milk can be treated with the enzyme lactase, which is responsible for hydrolysing lactose. This makes the milk lactose-free.

Beads are coated with the enzyme and placed in a column. The milk flows over the beads, and the lactose is hydrolysed, resulting in a lactose-free milk product suitable for consumption by those with lactose intolerance.

Suggest three reasons why attaching lactase to the beads is more efficient than adding lactase directly to milk products.

Sometimes smaller beads are used instead of larger beads.

Suggest a benefit of using small beads in the column.

Lactose-free milk produced in this way tastes sweeter than untreated cow's milk.

Suggest why.

The alginate beads inside the column were all the same size with a diameter of 2.5 mm.

Use the formula below to calculate the volume of one bead.

Microorganisms are used in various biotechnological processes.

State what is meant by biotechnology.

Give three examples of products that involve the use of biotechnology.

Bacteria and fungi can be used to produce food for humans.

Describe and explain three advantages of using bacteria or fungi to produce food for human consumption.

Microorganisms are also responsible for the spoiling of food.

Irradiation can be used to prevent food spoiling.

Explain how irradiation works to reduce food spoilage.

In 1958, scientists were successful in cloning the African clawed frog.

Since then, scientists have developed methods to clone mice from embryos.

These cloned mice can be used to investigate factors affecting the development and treatment of disease.

Give one advantage of using cloned mice to test for potential treatments for a disease.

Give one disadvantage of using cloned mice to test for potential treatments for a disease.

Further scientific developments resulted in the successful cloning of adult mammals.

Adult cell cloning can also be used to investigate the development and treatment of disease.

Suggest two potential applications of adult cell cloning.

The cloning of mammals still has limited success.

The diagram below shows information about the success of cloning using somatic cell nuclear transfer for two different animal species.

Using the information above, calculate the percentage of pregnancies that resulted in live births in mice.

Give three factors that should have been controlled when collecting the data in the table above.

A student wanted to transfer bacterial cells from a broth culture to an agar plate containing a sterile medium.

Describe how the student should use aseptic techniques to transfer the bacteria.

The student wanted to estimate the number of bacterial cells in the 30 cm³ broth culture.

He mixed 1 cm³ of the broth culture with 9 cm³ of water to make a second solution.

He then mixed 1 cm³ of this second solution with 9 cm³ of water to make a third solution.

He transferred 0.1 cm³ of the third solution onto the agar plate on which 16 separate bacterial colonies formed.

Calculate the number of bacterial cells in the original 30 cm³ broth culture.

Give your answer in standard form.

After the student made the agar plate, he placed it in an incubator.

Explain why agar plates should be incubated below 30°C in a school laboratory.

The diagram below shows the number of bacterial cells in a broth culture during a 24-hour period.

The bacterial population follow a standard growth curve.

Name phases A, B, C, and D in the diagram above.

Describe and explain the shape of the curve in section C in the diagram above.

Describe and explain the shape of the curve in section D in the diagram above. 

Calculate the growth rate constant (k) for section B of this broth culture.

Use the formula below:

where

N_t = size of population at time t

N₀ = initial size of population 

t = time