Nutrient Gas Exchange

Question 1

Non vascular

Answer 1

No transport system. Absorption and secretion by diffusion and osmosis thorugh surface of the plant

Question 1

Vascular Plant

Answer 1

Most plants, move substances from one part to another.

Question 2

Xylem

Answer 2

Transport of water and water soluble nutrients and minerals.
Phloem: Tissue composed of thin walled cells that transport sugars in the form of dissolved surcose

Question 3

Root system

Answer 3

Anchors the plant
Absorbs water and inorganic nutrients. Through the epidermis, high surface area, extends through the branches, anchors leading to high absorption. This increases SA by 12x
Water enters via root. The flattened nature of epidermis cells increases exposed surface.

Question 4

Movement of Substances in root hairs

Answer 4

Water uses osmosis, and mineral diffuse. If concentration gradient is not high enough than active transport will be used.

Question 5

Shoot systems: Stems

Answer 5

Structural support and transport pathway. Contains dermal tissue, vascular tissue, ground tissue.

Question 6

Dermal tissue

Answer 6

Outer layer of stem
Waterproofing
Protection
Control of gas

Question 7

Vascular tissue

Answer 7

Xylem and Phloem tissues in stem. Vascular bundle structure. Roots to leaves. Water and minerals are absorbed by the roots then move into Xylem.
Photosynthesis products move from leaves to all plant parts via phloem tissue.

Question 8

Ground tissue

Answer 8

Stems fill in around vascular tissue.

Question 9

Shoot system leaves

Answer 9

Absorb sunlight and carbon dioxide
Sit or transpiration (Water evaporates from leaves)

Question 10

Leaves absorbing sunlight

Answer 10

High surface area allows for increased absorption of light energy by chlorophyll. Thin structure allows there to be no internal cell too far away from the surface to receive light. Cells in mesophyll are responsible for most of the plants photosynthesis. 2 types are palisade and spongy cells.

Question 11

Palisade cells

Answer 11

Elongated cells which are dense with chloroplasts. They are immediately below upper epidermis, thus exposed to high numbers of sunlight and thus more chloroplasts.

Question 12

Spongy cells

Answer 12

End importance cells. Situated between palisade and the lower epidermis. Low chloroplasts and are irregular shape and distribution. This is where cellular respiration takes place. The irregular numbers allows gas flow between photosynthesis and cellular respiration reactions.

Question 13

Leaves mold to their habitat

Answer 13

In hot dry habitats plants have a waxy cuticle to reduce water loss and smaller leaves to reduce sunlight. IN rainforests with little sunlight they are large thin leaves that are dark to absorb as much as possible. The high humidity means the plant experiences water loss.

Question 14

Gaseous exchange

Answer 14

Protective layer, epidermis, covers surface of the leaves top and bottom, simple and flattened. Protects the inner tissues and secretes waterproof cuticles to prevent evaporation.

Question 15

Within the epidermis

Answer 15

Guard cells control the exchange of gases and difference in water. Bean shaped and occur in pairs
Surrounds a pore known as stoma which occurs in the underside of the leaf.

Question 16

Transport

Answer 16

Tissue in the centre of the root, continuous passing up the stoma and into the veins. Main vein is midrip. COntains Xylem and Phloem tissue. Extended vascular tissue also plays role in supporting thin leaf blade.

Question 17

when does cellular respiration occur

Answer 17

During the day and the night.

Question 18

During the day cellular respiration

Answer 18

Comes from oxygen produced as a bi-product of photosynthesis. However photosynthesis is at a higher rate than cellular respiration therefore any oxygen not used is released.
Co2 released by CR is used by photosynthesis when PS is at a higher rate CR, PS absorbs from the environment.

Question 19

Imaging technologies

Answer 19

MRI: Radio Waves and magnets to create 3d image.
PET: Positron emission tomography, uses radioisotopes.
X-Ray X Ray beam rotated includes lots of 3d images.

Question 20

Melvin Calvin

Answer 20

Used Radioactive carbon-14 showed how sunlight acts on chlorophyll
Awarded noble prize in 1961.

Question 21

Radioisotopes in plants

Answer 21

Radioactive, waves can be traced through physical and biological systems. Determines whether oxygen released originated from water or carbon dioxide.
Plants were given radioactive water showing ewater was the source of oxygen not carbon dioxide.

Question 22

Real time radioactive imaging system

Answer 22

Non-destructive
Using carbon 11 and tracing decay.

Question 23

Gas exchange in plants

Answer 23

Leaves are large and flat. to maximise the surface area. Most gaseous exchanges occur at the stomata lenticels.

Question 24

Stomata

Answer 24

Pores, mostly found on the underside of the leaf. Bordered by two bean shaped cells. The stomata opens and closes to reduce the loss of water.

Question 25

Opening and closing of the stomata

Answer 25

When guard cells fill with water they become turgid causing the walls to be pulled apart by the pressure. This allow water to flow through. When stomata looses water the pressure is relieved closing the pour. The stomata opens and closes according to light and concentration gradient of gases.

Question 26

Lenticels

Answer 26

For woody plants so oxygen and carbon dioxide can diffuse.

Question 27

Gas exchange in animals definiton

Answer 27

The movement of gases between the internal and external environment by diffusion across cell membranes. The respiratory systems enables this exchange of gases.

Question 28

Shared gaseous structure characteristics

Answer 28

High surface area, branching, flattening and folding Most thin surface Close proximity to transport system Go along the concentration gradient

Question 29

Gaseous exchange in mammals

Answer 29

Terrestrial animals, reduce the loss of water. Exchange structures are located within the lung in the alveoli. Each component of the air is connected to the external environment and surrounded bu thin walled capillaries.

Question 30

Alveoli as gaseous exchange structures

Answer 30

High surface area due to 300 alveoli and 280 capillaries Each alveoli is one cell think, flattened cells and thin. The surface area remains moist because of the mucus lined epithelium. high capillaries = high diffusion.

Question 31

Exchange in fish

Answer 31

Gases have a low solubility in water. Therefore gas exchange structure extracts as maximum as possible. Requires constant water flow, water enters, flows over the gills. leaves fish via gill slits.

Question 32

Gas exchange features common to all multicellular organisms

Answer 32

Large surface area, small distance for gases to diffuse, Moist at all times Favourable concentration.

Question 33

Respiratory system in insects

Answer 33

Spiracles: Take in and expel air (Breathing pores). Valves open and close spiracles which decreases the effects of drying. Tracheal tubes carry air directly to body cells they are made out of tough thick spiral rings called CHITIN. They branch into smaller tubules called Tracheoles which increases surface area. End are filled with water fluids where gases can dissolve. Muscular movements of thoracic and abdomen help regulate.