DP Biology Questionbank

Evaluate the limitations of using a potometer in the investigation you suggested in (a).

The image is a cross section through an Ammophila leaf, which grows on coastal sand dunes.

[Source: Charles Good: The Ohio State University at Lima]

What feature suggests that Ammophila is a xerophyte?

A. The leaf surface area is increased.

B. The rolled leaf reduces the upper epidermis area.

C. The rolled leaf protects the lower epidermis from the wind.

D. The lower epidermis can transpire more easily.

Label with an R the tissue where the red dye would appear.

Label with a C the tissue where organic compounds are transported.

In the micrograph of a plant stem, which letter indicates the xylem?

[Source: adapted from Kelvinsong/https://creativecommons.org/licenses/by/3.0/deed.en]

The mean stomatal density for the lower epidermis of P. decandrum was around 600 per mm². Predict how the stomatal density for the upper epidermis would compare.

Describe the processes that cause water to move from the roots of plants to their leaves.

The apparatus in the diagram was used to assess the effects of factors on transpiration rates.

[Source: Republished with permission of Springer-Verlag from Experimentelle Pflanzenphysiologie: Band 2, Peter Schopfer, 1st edition, 1st Jan 1989; permission conveyed through Copyright Clearance Center, Inc.]

Which factor would be a controlled variable in an experiment designed to assess the effects of temperature on transpiration rate?

A. The opening and closing of stomata

B. The intensity of light striking the plant

C. The height of the water in the reservoir

D. The evaporation of water from the leaves

Distinguish between the xylem and phloem of plants.

Describe how changes in weather conditions affect the transport and loss of water in plants.

Describe the transport of organic compounds in vascular plants.

Plants have widespread influences, from food chains to climate change.

Explain the process of water uptake and transport by plants.

Which letter identifies phloem?

[Source: E R DEGGINGER/Getty Images]

In a plant, what tissue(s) is/are specially adapted to transport sucrose?

Explain how organic compounds are transported within plants.

The micrograph shows the cross-section of the vascular tissue in a dicotyledonous root. Which letter identifies phloem sieve tubes?

[Source: Wendy Paul]

The image shows part of a section through the stem of a non-woody plant.

The image shows part of a section through the stem of a non-woody plant. Where does transport of sucrose occur?

[Source: Courtesy of Kelly Cude, PhD, Professor Biological Sciences, College of the Canyons.]

Distinguish between the xylem and phloem of plants.

What is/are the effect(s) of auxin in plants?

I.   Increasing the rate of cell elongation in stems
II.  Changing the pattern of gene expression in shoot cells
III. Detecting the direction of light

A. I only
B. I and II only
C. II and III only
D. I, II and III

Compare the pattern of GH3 transcription with the pattern of auxin concentration in the stem base control cuttings. You may use the table provided to help you to record the patterns before you compare them. (Please note: a simple
comparison in the table will not gain marks)

The image shows seedlings that have been exposed to unidirectional light.

[Source: The Micro Gardener (https://themicrogardener.com/prevent-fix-leggy-seedlings/)]

Which statement explains the growth towards the light source?

A. Light causes auxin to inhibit cell division in the shoot meristem.

B. Light causes auxin to promote cell division in the shoot meristem.

C. Auxin is concentrated in the side of the shoot with light and inhibits cell elongation.

D. Auxin is concentrated in the side of the shoot without light and promotes cell elongation.

The photomicrograph shows a section through the top of a plant shoot.

[Source: Charles Good: The Ohio State University at Lima]

What are the structures labelled X and Y?

Outline how the hormone auxin controls phototropism in plant shoots.

On the diagram, label the testa and the radicle.

The diagram shows a plant shoot and the direction of the light which the shoot received.

[Source: USDA-NRCS PLANTS Database. Available at: https://commons.wikimedia.org/wiki/File:Alnus_seedling_drawing.png
[Accessed 30 November 2021].]

What are the direction of movement and the effect of auxin in the tip of a plant shoot when receiving light from one side?

Outline the extension of the stem in plants.

The picture shows lentils sprouts growing towards a light source from the left.

Plants have widespread influences, from food chains to climate change.

Draw a labelled diagram of the internal structure of a seed.

Calculate the difference (in mm²) in the mean leaf area of L6 at the start of stage 4 between the leaves of plants grown in long days and short days.

Suggest reasons for the difference in end of day starch concentrations in stage 2 (S2) for the plants grown in long days and short days.

The image shows a cross-section of a flower.

[Source: © International Baccalaureate Organization 2019]

Where does production of haploid gametes occur?

A. I and II only

B. III and IV only

C. I and III only

D. II and IV only

Draw a half-view of an animal-pollinated flower.

The graph shows how the mass of a bean seed from which all water has been removed (dry mass) changes during germination.

What can be deduced from the graph?

A. The plant loses more water during period X than during period Y.

B. During period Y, photosynthesis occurs but not respiration.

C. During period Y, more CO₂ is fixed in photosynthesis than is released by cell respiration.

D. The seeds were not exposed to the correct temperature for germination during period X.

Explain how some plant species are able to respond to changes in their abiotic environment and flower at a precise time of the year.