Tropisms and Photosynthesis

Tropisms Tropism is the growth of a plant towards or away from a stimulus A Stimulus is something that causes change like light, gravity, water, or contact. There are positive and negative tropisms: Positive Tropisms are towards the stimulus Negative Tropisms are away from the stimulus

Phototropism/Gravitropism

Phototropism Types of Tropisms ‘Photo-’ means ‘light’ Phototropism is the bending of a plant towards light (remember that ‘towards’ is a positive tropism) This is caused by a plant hormone called Auxin Auxin promotes plant growth and cell elongation.

Gravitropism AKA Geotropism Types of Tropisms Gravitropism AKA Geotropism ‘Gravi-’ refers to ‘Gravity’ Gravitropism is the bending of a plant towards or away from gravity -Roots are a positive gravitropism and grow towards gravity -Shoots are a negative gravitropism and grow away from gravity

Thigmotropism

Thigmotropism Types of Tropisms ‘Thigmo-’ refers to ‘Touch’ Thigmotropism is the bending of a plant in response to touch You see this with vines that twist around trees or buildings This is what venus fly traps are able to do

Venus Fly Traps

Types of Tropisms Hydrotropism Hydro – means “water” Hydrotropism is the bending of a plant towards water. This is what happens with tree roots when they get into the pipes in your house.

Photosynthesis Reactants → Products Plants utilize tropisms to increase the amount of sunlight that they can acquire to maximize photosynthesis Reactants → Products

Photosynthesis Here is the equation with everything on the correct side. Check your work, but remember that it doesn’t matter which order you have them in so long as they are on the correct side. __CO2 + __H2O + Energy  __C6H12O6 + __O2 Now Balance the Equation

Photosynthesis Your final equation should look like this: Now write the equation for Respiration!

Name that Tropism! Negative Gravitropism What type of tropism is this? Positive or Negative? Negative Gravitropism

Name that Tropism! Positive Thigmotropism What type of tropism is this? Positive or Negative? Positive Thigmotropism

Name that Tropism! Positive Gravitropism What type of tropism is this? Positive or Negative? Positive Gravitropism

Name that Tropism! Positive Phototropism What type of tropism is this? Positive or Negative? Positive Phototropism

Positive Hydrotropism Name that Tropism! What type of tropism is this? Positive or Negative? Positive Hydrotropism

Name that Tropism! Positive Thigmotropism What type of tropism is this? Positive or Negative? Positive Thigmotropism

Name that Tropism! Negative Phototropism What type of tropism is this? Positive or Negative? Negative Phototropism