Tropisms

All living organisms, including plants, respond to stimuli

stimulus vocabulary word! stimulus - anything that causes a reaction or change in an organism.

response response - an organisms reaction to a stimulus. vocabulary word! response - an organisms reaction to a stimulus.

stimulus/response

internal stimulus vocabulary word! internal stimulus – a stimulus coming from inside an organism chemicals and hormones Quickly draw this in your notes

external stimulus vocabulary word! external stimulus – stimulus coming from outside an organism light, touch, water, gravity, electricity, temperature, darkness etc… Quickly draw this in your notes

tropism vocabulary word! tropism - automatic movement by an organism toward or away from a stimulus positive (toward) negative (away)

phototropism https://www.youtube.com/watch?v=_QBhAwiks1Y

phototropism a response toward or away from light positive – toward light negative – away from light

phototropism Find the square on your cut-out page that shows phototropism. On the line above the picture, write phototropism On the lines under the picture, write the definition - a response toward or away from light Paste it onto your notes If you have time, you can color the picture

gravitropism https://www.youtube.com/watch?v=mYZXax8V_L0 http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/tropisms.html

gravitropism a response toward or away from gravity positive - roots growing down negative - stems growing up

hydrotropism response toward or away from water Usually occurs only in the roots

Thigmotropism https://www.youtube.com/watch?v=9sggQQuBU40 https://www.youtube.com/watch?v=_SIJ4ov_FxA https://www.youtube.com/watch?v=xZ3qR6SkuKo

thigmotropism a response toward or away from touch Vines Venus flytrap

Emergence of Seedlings Unbalanced forces allow seedlings to push their way through the soil and sometimes rock https://www.youtube.com/watch?v=ZK4LjURtaDw

Turgor Pressure https://www.youtube.com/watch?v=fhsurzE_-J0

Turgor Pressure force in the form of water pressure helps some plants stand upright. In animals, it also helps blood move around the body

emergence of seedlings thigmotropism phototropism geotropism organism’s response to light organism’s response to gravity organism’s response to touch hydrotropism turgor pressure emergence of seedlings organism’s response to water pressure inside the plant that allows it to stand up. seedling pushing up through the ground