Plant growth and distribution

Grade B – Discuss the factors affecting the growth and distribution of plants, including:nutrients; light; temperature; carbon dioxide; oxygen; plant ‘hormones’.Grade A – Compare natural fruit initiation in plants and how it can be manipulated with artificially using hormones Grade A* – Evaluate data on how environmental factors affect the distribution of plants and synthesize your own ideas about the effects of change in the environment.

Design an experiment to investigate the rate of photosynthesis

• List all the variables that might affect photosynthesis

• Draw a diagram of the equipment you will use in your experiment

• Explain how your experiment tests one variable and controls all other variables.

Sketch the plant shoot and the effect that the plant hormone auxin has.

Plant shoot after hormone

What stimuli do plants respond to?

• Light

• Gravity

• Water

• Touch

• Gibberellin – the plant equivalent to HGH.

How are fruits made?

How are seedless fruits made?

Homework

• What do the following hormones do?– Auxin; Gibberellins; Cytokinin; Absiscic acid

and ethylene

• What part(s) of the plant is/are acted on by the hormone?

• Explain the terms: haptotropism; hydrotropism; geotropism; phototropism.

Design an experiment to investigate the rate of photosynthesis

• List all the variables that might affect photosynthesis

• Draw a diagram of the equipment you will use in your experiment

• Explain how your experiment tests one variable and controls all other variables.

Study the diagram and start to think what environmental factors will affect plants A, B, C and D.

The additional information about the habitats might help you.

Take part in a group discussion to answer the Qs on on the following slide.

In your group, discuss the following points.

• What are the main conditions in each habitat A–D? Consider abiotic and biotic factors.

• How do these conditions determine the type of plant that can live there?

• Can you think of specific plants that live in these conditions?

• What are the adaptations shown by cacti to desert conditions?

• What are the adaptations shown by water lilies to their freshwater habitat?

Where is the light coming from?Why have you suggested that direction?Why does the plant grow in this manner?