Biol 371 Samuel Flashcards

Question

What is a hydroponic culture, how can it be utilized?

Answer 1

Is when you grow plants in solution w out soil, can see what nutrients is important to plant using this as you can remove one nutrient in the water at a time. If plant grows bad you removed an essential element- one that is necessary for growth/reproduction, cannot be subbed, and has metabolic roles.

Answer 2

Is the combo of water and dissolved substances that coats soil particles and fills pore space. Is available for plant uptake after gravity drainage (in which water is drained and concentration of ions and nutrients is increased).

Answer 3

Because humus particles are neg charged so attracted to pos water molecules Because clay is alkaline due to minerals, gives it a high ph (more basic and more neg charged) so it sticks to water molecule smore.

Answer 4

Minerals are dissolved in water and passively enter plant roots in their dissolved form, they are selectively absorbed by roots via ion-specific transport proteins

Answer 5

Because soil is negatively charged so it repulses the anions but binds tight to cations, makes it so anions enter soil solution and are uptook by plants easier. However, they're also washed away because of this easier.

Answer 6

The solution moves in and out of roots, extensive root systems are adaptations to limited mineral nutrients, and they make up 20-50% of the plants mass

Answer 7

As dissolved cationic minerals are bound onto surface of clay particles (adsorbed), it's hard to take them up, plan addresses this by pumping out H+ in order to replace the cations on the soil with H+ so the minerals can then be taken up by the roots. Plants also does cation exchange by respiration, in which it realses co2 that creates carbonic acid which dissociates into H+- displacing the minerals which will be uptook by plant.

Answer 8

Anions (NO3, SO4, AND PO4) are neg so they don't bind to soil and go up plant roots readily, however this is also bad because water can leech them out of the soil and run off into groundwater and (NO3 and PO4) can cause eutrophication.

Answer 9

Become acidic so the negative charges on the soil now become positive and cations are easily leeched out of the soil solution.

Answer 10

solutes move down a concentration or electrochemical gradient. They diffuse over a semi permable membrane or they are released through transport proteins.

Answer 11

Is moving against an electrochemical or concentration gradient (ex transport pumps)

Answer 12

Root hairs, mycorrhizae.

Answer 13

They Greatly increase root surface area, absorb water and minerals

Answer 14

Mychorizzae increases plants supply of phosphate and plant gives the mychorizzae carbon, fungus interacts with root to mobilize phosphate

Answer 15

Because charge particles require a channel or transport- can't just diffuse.

Answer 16

Want to reduce nitrogen fertilization as each molecule of nitrogen is 300x more potent than CO2.

Answer 17

Into and out of cells, cell to cell, and over long distances such as root to shoot.

Answer 18

Passive and active transport

Answer 19

Are able to move buckets of water, moves a hundred gallons of water, 90% of it is used in transpiration and 10% in metabolism

Answer 20

Answer is in the wood of tree, There’s tube sin trunk that extend whole length of trunk, water gets filtered into xylem vessels which move up water, then move into branches and then leaves

Answer 21

Stomata pore adjusts to increase/lack of water in soil that’s being pulled up through xylem in plant. If the soil is dry a hormone is triggered that shuts down the stomata pore. The cells have to consistently adjust themselves to remain turgidity this way.

Answer 22

minerals and water being transported across cell membranes. Mineral and water being pulled into and out xylem and phloem

Answer 23

Moving substances from root to shoot

Answer 24

Passive movement of water across a selectively permeable membrane

Answer 25

A protein that allows quick movement of water through hydrophobic environments

Answer 26

Is the potential energy of water and is a driving force in the directionality of water. Water potential is measured in megapascals and is the sum of its components (pressure potential and solute potential)

Answer 27

Water moves from High water potential to low water potential

Answer 28

1 megapascal

Answer 29

Anytime there’s a solute in the water, the water potential drops

Answer 30

. Pressure potential is the force required to stop water movement.

Answer 31

Positive pressure increases water potential, negative pressure reduces water potential.

Answer 32

Central vacuole's tonoplast membrane

Answer 33

Yes for example water potential of dry soil is low which is why plants get plasmolyzed in dry soil as water moves down to soil.

Answer 34

It goes up because water rushes into the cell as the solute conc is high, this will increase the pressure potential resulting in a turgid cell.

Answer 35

Solute will rush into vacuole in order to avoid being plasmolyzed, this will then decrease the water potential of the vacuole/cell, water will rush in and increase the pressure potential so vacuole maintains turgidity and water will continue to rush in until equilibrium between outside and inside of the cell is the same.

Answer 36

Water always follows solute!

Answer 37

Apoplastic pathway- is outside of the cell, nothing gets into the cell and it's a passive transport Symplastic- Things are being transported into the cell, water flows from the cytoplasms via plasmodesmata. Cell to cell movement.

Answer 38

The openings between cells are called plasmodesmatas- can have 20 to 50 connections within a single cell.

Answer 39

Solute moves from cell wall to cell wall and travels in the apoplast, diffuses across spongy cell wall

Answer 40

Symplast is cytosol and plasmodesmata (are channels in cell walls that connect cells together). So if sugar was in a mesophyll cell, and it went down the symplastic route that means the sugar will travel through symplast only and travels through cells through channels. Don’t ever have to cross plasma membrane or cell wall. Is active transport for sugars but passive transport through osmosis for water.

Answer 41

Solute travels from actual cells, not openings like plasmodesmata

Answer 42

Apoplastic is fastest route as solute doesn’t even enter cell and doesn’t have to through cytosol and organelles which are incredibly dense so take a long time to go through. Cell to cell movement is slowest.

Answer 43

Is layer in root that sits and screens solute to filter only what plant needs into cell, anything absorbed must go through endodermis

Answer 44

The apoplastic pathway, once things enter symplast there's no need for screening by the endodermal layer

Answer 45

They are actively transported as endodermal cells (casparian strip) only let certain ions pass through.

Answer 46

Is in roots is also called the endodermal layer forces apoplastic water pathway to be converted into symplastic pathway before entering xylem by passing it through the plasma membrane

Answer 47

waxy cells

Answer 48

It stops solutes from leaking out back by being hydrophobic.

Answer 49

Xylem- considered apoplastic route cause it's not a cell.

Answer 50

Cohesion and tension, in trees the tallest ones have reached their growth limit because this mechanism has reached its own limit

Answer 51

Evaporation of water out of plants Greater than water used in growth and metabolism

Answer 52

This mechanism is driven by transpiration, water drive sup length of plant in order to transpire from the top of it, after a molecules of water evaporates than another water molecules replaces it immediately through cohesion (as water molecules are attracted to each other).

Answer 53

Lignin in secondary cell wall (xylem) is strong so holds up column, weight of column is heavy, and adhesive forces in xylem-water prevents it from collapsing.

Answer 54

Large volume of air space provides surface area for evaporation Stomata: Thousands to millions of stomata Short cell distances to xylem: each square cm contains thousands of xylem veins

Answer 55

This transpirations also exerts tension on the xylem allowing it to stay up right as thin film of water is connect to xylem

Answer 56

Positive pressure in roots forces xylem sap upwards and moves water up small distances. However you still need the main mechnaism of transpiration.

Answer 57

When root pressure strong enough to force water out of leaf openings Water is pushed up and out of veins

Answer 58

Long-distance transport of substances via phloem, this substance is phloem sap and contains amino acids, organic acids, organic nitrogen compounds, hormones, and other signal molecules, is more than just sugar

Answer 59

Differences in pressure between the source and sink regions drive the flow. So where it’’s lower in pressure in plant is where phloem sap goes.

Answer 60

Any region of the plant where organic substances can be loaded into the phloem ex: Sources- leaves as they put sugar into phloem

Answer 61

:Any region of plant where organic substances are unloaded from phloem Ex. sugars can get unloaded at roots which makes them sinks.

Answer 62

Phloem likes transporting sucrose- as it’s soluble, but not glucose.

Answer 63

sieve tubes, companion cells, and sieve plates

Answer 64

Sieve plates are on either side of sieve tube. Every single sieve tube is connected to a companion cell

Answer 65

Phloem starts from a cell called phloem mother cell can go through a symmetric or asymmetric division. If it’s symmetric division- the cell produced will have the same funcions If assymetric- the cell produced can do two diff functions. So after asymmetric division of phloem mother cell- the cells produced are the companion cell and sieve element The images above show the cells, with all organelles, they cells are connected through plasmodesmata. How do they transport sugar through all this clutter? The sieve tube go through partial cell death, clearing out organelles, take remaining organelles left after partial cell death and anchor them to the far ends of the cell. How can phloem be alive at maturity if it has no nucelous? This is because the companion cell holds the organelles that the sieve element needs, the sieve tube needs to be alive to import apoplastic sugars.

Answer 66

Both apoplastic and symplastic

Answer 67

No, substances have to eventually get into the symplast of the sieve tube to be transported.

Answer 68

active, Because the concentration of sugar is high in the sieve tube, to load more into it it needs to be active transport

Answer 69

Sucrose comes through smaller plasmodesmata into companion cells, processed into larger sugars and through larger plasmodesmata transferred to sieve tube (as sucrose) and then into phloem.

Answer 70

Pressure flow mechanism moves substances by bulk flow under pressure from sources to sinks Based on water potential gradients Load from source  transport in sieve tube  unload into sinks

Answer 71

Water gets loaded into sieve tube source as solute level is high so low water potential, this increases the turgor pressure, water then travels down to sink which has a low turgor pressure and moves backwards into xylem to start the process over again.

Answer 72

gas exchange is done by simple diffusion, to maximize this they put a short distance between cells and the external environment and create surface area through leaves

Answer 73

does all of gas exchnage

Answer 74

Two guard cells that surround a tiny pore called a stoma

Answer 75

Disadvantage is same pore controls water loss and taking in gases

Answer 76

Transpiration photosynthesis compromise- when stomata open you lose water good for transpiration but can cause excess loss of water and plants to wilt but stops photosynthesis, is a compromise do you wanna lose water or photosynthesize. Also cuticles reduce water loss but also limits co2 diffusion- again a compromise.

Answer 77

stomatal opening and closing is actively controlled by potassium, water follows potassium being transported into or out of guard cells- if in the stomatas open- if out it's closed

Answer 78

Abscisic acid, How do plants sense there’s not enough water in the soil, does this through abscisic acid that moves up xylem and signal stomata to close. Mesophylls cells from root take ABA and release it to guard cells which open and close stomata

Answer 79

Opening- Hydrogen ion gets pumped out to set a concentration gradient, Potassium ions flood into guard cells and as water follows solutes it gets pumped in after- this then causes the guard cell to open and pores to open as it becomes turgid Closing- ABA triggers potassium to be released out by entering guard cells and water follows it, this softens the stomatal pores and the stomata closes.

Answer 80

This is because the companion cell holds the organelles that the sieve element needs, the sieve tube needs to be alive to import apoplastic sugars.

Answer 81

nucleus, tonoplasts, rough er, ribosomes, cytoskeleton, and golgi