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DP IB Biology: HL

Topic Questions

Home / IB / Biology: HL / DP / Topic Questions / 9. Plant Biology (HL Only) / 9.3 Growth in Plants / Multiple Choice: Paper 1


9.3 Growth in Plants

Question 1

Marks: 1

Meristem cells at the tip of a growing shoot differentiate into specialised cells as the shoot grows, forming stems and other differentiated plant tissues e.g. ground tissues.

Which of A - D best explains why there is always a number of meristem cells in a shoot apex even as the shoot grows?

  • The coleoptile (early shoot) contains enough meristem cells to provide for a juvenile plant to grow into a fully-grown plant.

  • Mitosis in the shoot tip results in 2 daughter cells, one of which remains meristematic while the other cell differentiates.

  • Mitosis in the shoot tip results in 4 daughter cells, two of which remain meristematic while the other two differentiate.

  • The action of plant hormones reverses the effects of differentiation on certain cells, turning them back into meristem cells.

Choose your answer
  

Question 2

Marks: 1

The image below shows two tree species native to North America.

The Jeffrey pine (Pinus jeffreyi) typically grows to 45m height at maturity, whereas the silver maple (Acer saccharinum) would only grow to 25m. 9-3_q2h

Which table would be the best choice for predicting the levels of indole-3-acetic acid (IAA) at two parts of a typical growing shoot of these two trees?

  •  

    Jeffrey pine

    Silver maple

    At shoot apex High High
    At first axillary bud Low High
  •  

    Jeffrey pine

    Silver maple

    At shoot apex High Low
    At first axillary bud High Low
  •  

    Jeffrey pine

    Silver maple

    At shoot apex Low High
    At first axillary bud High Low
  •  

    Jeffrey pine

    Silver maple

    At shoot apex High Low
    At first axillary bud High High
Choose your answer
  

Question 3

Marks: 1

Which of A - D gives the most accurate description of how efflux pumps contribute to plant tropisms?

  • Efflux pumps pump low-density particles to the top of a horizontal root in order to initiate a positive gravitropism. 

  • Light denatures PIN3 proteins which leads to fewer efflux pumps, and hence less cell elongation, on the sunny side of a plant shoot. 

  • Efflux pumps are coded for by PIN3 genes and carry auxins from one cell to another in order to maintain an uneven distribution of auxins.

  • Efflux pumps carry auxins away from growing tissues on the removal of a stimulus, in order to maintain an even distribution of auxins.

Choose your answer
  

Question 4

Marks: 1

Which of the following statements apply to the use of microarrays in the study of plant growth?

  1. A microarray is used to ascertain whether a gene is being expressed or not.
  2. RNA in the tissue sample binds to short DNA probes by covalent bonding.
  3. The DNA probes carry a radioactive marker and can be visualised when they bind to a piece of transcribed RNA.
  4. Microarrays can reveal phenotypic traits that are not necessarily easily observable in an experiment.
  5. Microarrays will only display if a gene is being transcribed at the exact time of analysis.

  • I, IV and V

  • III, IV and V

  • All of them

  • I, III, IV and V

Choose your answer
  

Question 5

Marks: 1

The plant tissue cambium gets its name from the word cambio, which in Spanish means 'change'.

Which of A - D gives the best explanation for cambium tissue having this name?

  • Cambium can change its function from day to day depending on the requirements of the plant. 

  • The direction of flow in cambium vessels can change according to the needs of the plant at a particular time of day, or with weather fluctuations. 

  • Cambium can change, by differentiation, into xylem or phloem tissues as the plant grows.

  • Cambium has the ability to change the tropism responses of a plant's shoots and roots in response to external stimuli. 

Choose your answer
  
Key Concepts
Plant Growth