Ch 36

Question 1

Plant structure

Answer 1

Roots: anchor, absorb minerals/water, stores carbohydrates

Stem: support, transportation btwn leaves and roots

Leaves: photosynthesis (make sugars), gas exchange

Question 2

Plant chemistry

Answer 2

Water cohesion through hydrogen bonds. Water moves like beads on a string, pull one and they pull on the next.

Question 3

Plant physics

Answer 3

Water potential moves from high potential to low potential.

Question 4

Solute (isotonic, hypotonic, hypertonic)

Answer 4

Isotonic: normal, no net gain or loss of water

Hypotonic: water moves into cell (animal cell will burst)

Hypertonic: water moves out of cell (cell will shrivel)

Question 5

Transpiration

Answer 5

Moving water through evaporation and cohesion. Loss of water from the leaves mostly through stomata creates a force within leaves that pulls xylem sap upward

Question 6

Apoplastic route

Answer 6

Water moves through cell in between cell wall and cytosol

Question 7

Symplastic route

Answer 7

Water molecules move between cells through the shared cytosol

Question 8

Transmembrane route

Answer 8

Water molecules that can be transported through both the cell wall and the cytosol through the use of channel proteins and transport proteins

Question 9

Xylem

Answer 9

Transports water and minerals from roots to shoots

Only the youngest, outermost secondary xylem layer transport water. Although the secondary older xylem no longer transfer water, it does provide support for the tree

Question 10

Phloem

Answer 10

Transports products of photosynthesis from where they are made or stored to where they are needed

Question 11

Phyllotaxy

Answer 11

The arrangement of leaves understand. This is an architectural feature important in light capture. It is determined by the shoot apical meristem.

Question 12

Water potential definition and its measured in what?

Answer 12

The physical property that predicts the direction in which water will flow. This is affected by the solute concentration and the physical pressure.

Water potential refers to waters capacity to perform work when it moves from a region of higher water potential to a region of lower water potential

Measured in megapascals.

Question 13

What is the water potential of pure water in an open container under standard conditions?

Answer 13

0 MPa

Question 14

Water potential equation

Answer 14

Yw = Ys + Yp

Question 15

Solute potential

Answer 15

By definition the solute potential of pure water is zero. When solutes are added, they bind water molecules. As a result there are fewer free water molecules reducing the capacity of water to move and do work.

In this way an increase in solute concentration has a negative affect on water potential which is why the solute potential of solution is always expressed as a negative number.

Question 16

Pressure potential

Answer 16

Can be negative or positive. This is the physical pressure on a solution.

For example when a solution is being withdrawn by a syringe it is under negative pressure. However when it is being expelled from a syringe it is under positive pressure.

Question 17

Turbot pressure

Answer 17

When the protoplast (the living part of the cell, which also includes the plasma membrane) he presses against the cell wall creating what is known as the turgor pressure. This helps maintain the stiffness of plant tissues and also serves as a driving force for cell elongation.

Question 18

Casparian strip

Answer 18

A belt made of suberin, a waxy material impervious to water and dissolved minerals

Question 19

Xylem sap and its ascent

Answer 19

Water and dissolved minerals in the xylem

The ascent of xylem, like the process of photosynthesis, is ultimately solar powered. The absorption of sunlight drives most of the transpiration by causing water to evaporate from the moist walls of the mesophyll cells and lowers the water potential in the air space within a leave.

Question 20

Guttation

Answer 20

The exudate on of water droplets that can be seen in the morning on the tips or edges of some plants. Not the same as dew.

This is an example of pushing xylem sap.

Question 21

Sugar source

Answer 21

The plant organ that is a net producer of sugar, by photosynthesis or by breakdown of starch

Question 22

Sugar sink

Answer 22

The plant organ that is a net consumer or depository of sugar.

Question 23

Monocotyledonae traits

Answer 23

One seed leaf in embryo
Leaf veins are parallel
Flower parts arrange multiples of three
Root systems fibrous without traproots, all roots about the same size
Stand with vascular bundles complex the arranged in the pith tissue
Stem and route without cambium; does not form annual cylindrical layers of wood

Question 24

Dicotyledonae traits

Answer 24

Two seed leaves in embryo
Principal veins of leaf branch out from midrib forming a distinct network
Flower parts are usually arranged in multiples of four or five
Root system characterized by one woody traproot with branch roots growing from it
Stem with vascular bundles in a single cylinder
The cambium adds a new ring of wood each year or growing season

Question 25

Cortex (root)

Answer 25

Ground tissue, parenchyma cells, generally site of metabolic activity and contain starch storing bodies called plastids.

Question 26

Endodermis

Answer 26

Delineates the innermost boundary of the cortex, ground tissue The endodermis acts as a selective barrier that regulates the passage of minerals from the cortex into the vascular tissue

Question 27

Stele

Answer 27

A bundle of vascular tissue collectively known as the stele contains the xylem and phloem

Question 28

Pith

Answer 28

In monocots, the xylem are not centrally located in the steel, they form a ring around the central mass of parenchyma cells called the path

Question 29

Root cap

Answer 29

Zone of loosely packed cells at the extreme tip of the root

Question 30

Apical meristem

Answer 30

A region of tightly packed cells within the zone of cell division

Question 31

Zone of the elongation

Answer 31

A region behind the apical meristem containing cells whose length increases, forcing the root tip forward

Question 32

Root hairs

Answer 32

Epidermal cells that extend out into the soil greatly increasing the surface area of the root thus facilitating absorption