1 / 14

Gas Exchange in Plants

Gas Exchange in Plants. Plants do not have special respiratory or circulatory systems, and therefore must rely on the direct exchange of gases with their environment The and of plants depend on gas exchange with the air and the soil The surface of the root is covered with

skylar
Download Presentation

Gas Exchange in Plants

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Gas Exchange in Plants

  2. Plants do not have special respiratory or circulatory systems, and therefore must rely on the direct exchange of gases with their environment • The and of plants depend on gas exchange with the air and the soil • The surface of the root is covered with • Root hairs increase the and also provide a moist surface area for roots rhizomes root hairs surface area gas exchange

  3. As long as the soil is and contains, the oxygen will diffuse from the air into the air spaces of the soil and then into the moisture film surrounding the soil particles and root hairs • The dissolved enters the by diffusion and is then passed on to other cells of the root • At the same time diffuses out of the root hairs and into the soil aerated water oxygen root hairs CO2

  4. Gas Exchange in Leaves photosynthesis The main job of leaves in plants is During photosynthesis, plants absorb and give off During respiration plants absorb and give off During the day both process occur in the CO2 O2 O2 CO2 leaves

  5. Because gas exchange is constantly occurring, the leaf has to protect itself against too much water loss, therefore it is covered with a waxy waterproof coating called the • The leaf also has tiny pores in it called that allow for the passage of gases in and out of the leaf • These stomata (singular ) are bordered by a pair of • The guard cells allow the pore to be opened to permit for or close to prevent cuticle stomata stoma guard cells gas exchange water loss

  6. Cross section of a leaf:

  7. Gases are held in the and can be used for either respiration ( ) or photosynthesis ( ) • Every cell is close to air spaces so that the gases can readily into the cells and be used for either process intercellular air spaces O2 CO2 diffuse

  8. STOMATES & GUARD CELLS Scattered about the lower epidermis are small openings called stomata.  It is through these holes that carbon dioxide enters the leaf, & oxygen & water vapor exit. Each stoma is surrounded by a pair of guard cells.  When guard cells swell, the stomates open when the guard cells shrink, the stomates are closed.  Plants respond to changes in temperature & humidity by opening or closing their stomata (an example of maintaining ... homeostasis).

  9. Gas Exchange in Stems • Every stem contains • The green flexible stems of grasses and other nonwoody stems photosynthesize and thus contain • Woody stems contain small white markings called pores stomata lenticels

  10. Lenticels are normally found where stoma were once situated when the stem was young and capable of photosynthesis • Diffuses into the stoma or lenticels and enter the here every cell in the stem is able to obtain gases they need for photosynthesis or respiration O2 intercellular air spaces

  11. Quest Review on Monday Review Questions Page 277 # 1-3, 5-7, 9, 10, 17, 20, 22, 29

More Related