Plant Structure and Growth

Topic 9AHL IB BIOLOGY

STARTER: Label the parts of a flower

Learning Objectives• Draw and label plan diagrams to show the distribution of

tissues in the stem and leaf of a dicotyledonous plant.

• Outline three differences between the structures of dicotyledonous and monocotyledonous plants.

• Compare growth due to apical and lateral meristems in dicotyledonous plants.

• Explain the role of auxin in phototropism as an example of the control of plant growth.

GROUP THOUGHT: Can you list 3 differences between monocots and dicots?

GROUP THOUGHT: Why does mowing the lawn not kill the grass?

BONUS: Spot the grammar mistake!

http://www.uri.edu/cels/bio/plant_anatomy/images.html

http://bcs.whfreeman.com/thelifewire/content/chp35/35020.html

Watch this virtual experiment

What do you see happenning?Why do you think this is happenning?

What’s happenning here?

http://www.kscience.co.uk/animations/auxin.html

Past Paper Question(a) apical and lateral

(b) 2 maxStructure Monocotyledonous Dicotyledonusleaf parallel veins branched (net of) veins;seed one cotyledon two cotyledons;flower floral parts in multiple of 3 floral parts in multiple of 4 or 5;stem scattered vascular bundles ring of vascular bundles around central pith;root adventitious roots branched tap roots;

Award [1] for each correct line

(c) auxin produced at apical meristem / tip;transported to growing area / zone of cell growth;lateral transport to cells on shade side;results in cell expansion;shoot “grows” towards light source;experimental detail; 3 max