1.  Desert Plants  Root system Shallow to obtain water  Reduced leaves Cactus needles—reduced surface area  Thick stems To store water  Dormant Seeds Germinate only when enough moisture present

3.  Life in the water:  Have tissues with large air-filled spaces through which oxygen can diffuse down the stem  Seeds that float and delay germination  Specialized air roots that allow O 2 to get to the roots down in the mud  Salty conditions:  Specialized cells in the leaves that pump the salt out of the plant tissue onto the leaf surface where rain washes it off

4. The leaves of water lillies float on the surface, so that oxygen can enter through their stoma and travel down to the roots, which are under water.

5.  Poor soil:  If the soil can’t provide N 2, plants trap and digest insects that release (Nitrogen) N 2  Plants without Roots:  Live on body of another plant  No roots  live in a humid environment to retain/store water from rainfall Spanish Moss Venus Fly Trap

6. Orchids Spanish Moss

7.  Fighting insects:  Make/secrete chemicals that are toxic if eaten  Need for Pollination  Plants will mimic a pollinators mate Milkweed Wasp attempting to mate with the flower Ophrys speculum mimics a female wasp

8.  Auxins – Hormones found in plants that are responsible for growth in stem height.  These hormones are located at the tips of stems (at the apical meristems).  Are important for response to gravitropism and phototropism.

9.  Auxins – Responsible for growth in stem height  Cutting the apical meri- stems (tips) off of branches will cause growth in side branches.

10.  Cytokinins – Hormone that stimulates cell division and growth of lateral buds (side branches).  It also causes dormant seeds to sprout.

11.  Gibberillins- Plant hormone that produces dramatic increases in size mostly in stems and fruits.  Ethylene- Plant hormone that causes fruits to ripen.  Ethylene is released in response to auxin.

12.  The way in which plants grow in response to stimuli in their environment are called tropisms.  Main Types of Tropisms: 1. Geotropism or Gravitropism - Response to gravity 1. Phototropism - Response to light 1. Thigmotropism - Response to touch

13.  Causes the shoot of a germinating seed to grow out of the soil (against gravity).  Also causes the roots of a plant to grow with the force of gravity and into the soil.

14.  Causes a plant to grow towards a light source

15.  This experiment shows the importance of apical meristems to the growth of stems towards a light source.

16.  Apical Meristem - Region of cells capable of division and growth at root and shoot tips

17.  A plant can be affected by touch in many ways –  Plants touched regularly could have stunted growth  Vines and climbing plants form structures that attach themselves to things they touch. Some climbing plants have long, twisting leaf tips, or petioles that wrap tightly around small objects. Other plants have extra growths called tendrils that emerge near the base of the leaf and wrap tightly around any object.