On the following slides, the green sections are the most important – Underlined words = vocabulary! Hyperlinks are shown in purple. Background Image Plant Systems

Image The Texas Bluebonnet (Lupinus texensis) is our state flower and a plant native to Texas. Remember that plants are NOT dead, but very much alive and composed of eukaryotic cells! In this unit we will discuss the systems in plants, specifically transport, reproduction, and response. Introduction

Response Just like animals, plants respond to changes in their environments (called tropism) – Tropism Animation There are four main types of tropisms: Gravitropism/Geotropism Hydrotropism Phototropism Thigmotropism

Response Gravitropism/Geotropism = response in plants that make it grow either with the pull of gravity or against Positive gravitropism/geotropism is when roots grow in the direction of gravity Negative gravitropism/geotropism is when shoots (stems) grow away from gravity Negative geotropism Positive geotropism

Hydrotropism response Hydrotropism = response that bends the plant towards water (usually the roots) Hydrotropism response Normal plant response

Response Phototropism = response that bends the plant towards light

Response Thigmotropism = response that bends it around an object (EX a vine wrapping around an arbor)

Response Cont. http://withfriendship.com/images/h/38808/Tropism-picture.gif

Response Cont. Another type of response, specifically to changes in pressure, is called a nastic response. The most common example is the infamous Venus flytrap which closes its leaf when the plant senses an insect to digest nutrients using enzymes. Nastic Slideshow http://www.justvenusflytraps.com/images/homepageimage.jpg

A hormone is a chemical produced in one part of an organism that is transported to another part where it causes a physiological change - plant hormones regulate the growth and development in plants – Image Some hormones include: Auxins – promote cell elongation and growth Gibberellins – promote cell elongation, bud development and seed germination Cytokinins – stimulate mitosis and cell division Plant Hormones

Plants provide consumers with oxygen to breathe, food, shelter, as well as cleaning the air and water for the planet. Just like animals, plants are active responders within various environments to survive and thrive. Their use and importance is numerous; humans use plants with healing properties in medical treatments. Photograph by Luis del Río Conclusion