P1 3-4 mark EQs

Scientists were investigating the effect of trehalose on the growth rate of a strain of bacteria by growing different populations on separate agar plates.

Describe how the scientists could use aseptic techniques to transfer the strain of bacteria in liquid culture from a bottle onto an agar plate [3 marks]

Scientists were observing antimicrobial-polypeptides (APs) on prokaryotes using a transmission electron microscope. They stained the APs using a monoclonal antibody with gold attached to it.

Suggest how these techniques allowed observation of APs on prokaryotes [3 marks]

Describe viral replication [3 marks]

Describe what the scientists should place in the control tubes in this investigation [3 marks]

Give three conclusions you can make from Figure 8 [3 marks]

Explain the rate of transpiration between 5am and midday shown in Figure 9 [4 marks]

The higher rate of transpiration at high tide shows that the mangrove tree is absorbing water from the sea water around its roots.

Describe an experiment you could do to investigate whether the mangrove root cells have a lower water potential than the sea water.

You are given: a piece of fresh mangrove root, sea water and access to laboratory equipment [4 marks]

Explain the position of the bands of ribosomes in tubes A and B in Figure 10 [3 marks]

Damage to the gills of a fish caused uncontrolled cell division in the cells around the capillaries in the gill filaments.

Other than surface area:volume ratio, describe one way this uncontrolled cell division changes the gills.

Explain how this difference would affect gas exchange [3 marks]

Describe the processes of facilitated diffusion and active transport [3]

Vitamin A is a fat-soluble substance.

Micelles are involved in the process of vitamin A absorption.

Describe the process of vitamin A absorption into cells lining the ileum [3]

Describe how we breathe in [3]

Molasses contains the sugars sucrose, glucose and fructose. A student used a biochemical test for reducing sugars on a clear sample of molasses.

Describe the biochemical test for a reducing sugar and explain the result expected from the test on the sample of molasses [3]

Molasses contains the sugars sucrose, glucose and fructose.

Give three structural differences between an mRNA molecule and a tRNA molecule [3]

Describe the role of micelles in the absorption of fats int the cells lining the ileum [3]

What are three differences between DNA in the nucleus of a plant cell and the DNA in a prokaryotic cell [3]