Tropisms

Today… Complete and turn in stomata lab Roots, stems and leaves review sheet Tropisms notes Tomorrow we will be setting up 2 labs… Grades go in today… all makeup work must be turned in. Did you know – there is more fecal matter on a shopping cart at the grocery store than there is on the toilet at the grocery store!

It costs an average of $5,000 to raise a dog to ten years old. Dalmatian puppies do not have any spots on them when they are born. They actually develop them as they get older. There is a doggy disco held in Italy every year where owners can dance with their dogs.

Plant hormones produced by the plant affect growth and development.  Plants are sensitive to light, gravity and moisture.

Phototropism—response to light Geotropism—response to gravity Hydrotropism—response to water Thigmotropism—response to touch

A tropism is a growth movement whose direction is determined by the direction from which the stimulus strikes the plant. Positive = the plant, or a part of it, grows in the direction from which the stimulus originates. Negative = growth away from the stimulus.

Gravity = gravitropism Plants respond to: Light = phototropism Stems are positively phototropic. Roots are negatively phototropic. Gravity = gravitropism Stems are negatively gravitropic while roots are positively gravitropic.

The adaptive value of these tropisms is clear. Roots growing down and/or away from light are more likely to find the soil, water, and minerals they need. Stems growing up and toward the light will be able to expose their leaves so that photosynthesis can occur.

Complete the help wanted brain teaser… We will begin our lab shortly Three strategically placed trees around a home can save that household 50% on air conditioning bills.