Chapter 38- Transport in plants Flashcards Preview

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Flashcards in Chapter 38- Transport in plants Deck (18):

How does water enter/exit a plant

enters roots from soil
-moves to xylem
-leaves through stomata


how does water move through a plant? (3 things)

1. root pressure-pushing of water entering roots
2. capillary action (xylem)-push/pull due to cohesion/adhesion
3. transpiration(leaves)-a sort of pull


how do substances other than water enter a plant?

active transport through protein transporters
-facilitated diffusion or active transport


what enhances osmosis in plants?

aquaporins speed up osmosis but do not change the direction of water movement


what are the 3 transport routes of water

1. apoplast route-movement through cell walls and space btwn the cells
2.symplast route-cytoplasm contiuum between cells connected by plasmodesmata
3. transmembrane route-membrane transport between cells and across the membranes of vacuoles within cells


How do ions accumulate in root cells

active transport because mineral ion concentration in the soil is much lower than the plant


What are essential minerals to plants

phosphorus, potassium, nitrogen, and calcium


what regulates transpiration in plants

guard cells


how do guard cells open

they are hypertonic to surrounding cells, so water flows into them and turgor pressure opens them up


explain how water and co2 entry can be controlled

stomates are usually open during the day (take in co2) and closed at night (prevent water loss)
-can open at night for low co2 levels
-can close during day to prevent water loss


how does the transpiration rate increase?

increases with temperature and wind velocity


how does transpiration rate decrease?

decreases with increasing atmospheric humidity due to more water vapor in atmosphere


How do plants limit water loss in drought conditions

-loss of leaves
-reducing number of stomata


what are the negative effects of flooding on a plant

abnormal growth
-oxygen deprivation


How do plants deal with salty environments (3 ways)

-supply oxygen to submerged roots and control salt balance
-secrete salt
-leaves with large amounts of water to dilute salts
pneumatophores-long air filled roots that emerge above mud to give oxygen to submerged roots


What does the Phloem do

transports mono and disaccharides to rest of plant for energy needs and storage
-transports hormones, mRNA, and other molecules


what is translocation

in the phloem, it provides building blocks for actively growing regions of the plant


What is the pressure flow theory

model describing the movement of carbohydrates in phloem
-dissolved carbohydrates flow from a source (tissues) and are released at a sink (developing fruit, growing root and stem tips)