#separator:tab #html:true "What is<span style=""background-color: rgb(0, 0, 127);""> water </span>in a plant absorbed by in the<span style=""background-color: rgb(0, 0, 127);""> roots</span> ?""In plants water is absorbed by the roots through extensions called <span style=""background-color: rgb(0, 0, 127);"">root hairs&nbsp;</span>" "Through which <span style=""background-color: rgb(0, 0, 127);"">vessel</span> is water <span style=""background-color: rgb(0, 0, 127);"">transported</span> by in <span style=""background-color: rgb(0, 0, 127);"">flowering plants</span> ?"xylem vessel - hollow, thick-walled tubes&nbsp; "What is the <span style=""background-color: rgb(0, 0, 127);"">name </span>of the process which is the <span style=""background-color: rgb(0, 0, 127);"">main force</span> that <span style=""background-color: rgb(0, 0, 127);"">pulls water </span>through <span style=""background-color: rgb(0, 0, 127);"">xylem vessels</span> in the <span style=""background-color: rgb(0, 0, 127);"">stem</span> of a plant ?""A process called <span style=""background-color: rgb(0, 0, 127);"">transpiration</span> - <span style=""background-color: rgb(0, 0, 127);"">evaporation</span> of water from the leaves&nbsp;" "Where is the <span style=""background-color: rgb(0, 0, 127);"">energy</span> for transpiration supplied from ?""The <span style=""background-color: rgb(0, 0, 127);"">sun&nbsp;</span>" "What<span style=""background-color: rgb(0, 0, 127);""> type</span> of process is tranpiration (active or passive) ?""<span style=""background-color: rgb(0, 0, 127);"">passive&nbsp;</span>" "Where does water <span style=""background-color: rgb(0, 0, 127);"">start</span> and <span style=""background-color: rgb(0, 0, 127);"">end</span> up for transpiration ?""- start from the point where water <span style=""background-color: rgb(0, 0, 127);"">evaporates</span> from the <span style=""background-color: rgb(0, 0, 127);"">surfaces of cells</span> surrounding the <span style=""background-color: rgb(0, 0, 127);"">stomatal air space</span>&nbsp;<br>- end where water vapour <span style=""background-color: rgb(0, 0, 127);"">diffuses</span> out of the <span style=""background-color: rgb(0, 0, 127);"">stomatal pore&nbsp;</span>" "How does <span style=""background-color: rgb(0, 0, 127);"">humidity</span> allow <span style=""background-color: rgb(0, 0, 127);"">water vapour molecules</span> to diffuse out of the <span style=""background-color: rgb(0, 0, 127);"">air spaces</span> into the <span style=""background-color: rgb(0, 0, 127);"">surrounding air&nbsp;</span> (in steps) ?""1) The <span style=""background-color: rgb(0, 0, 127);"">humidity</span> of the atmosphere is usually <span style=""background-color: rgb(0, 0, 127);"">less</span> than that of the <span style=""background-color: rgb(0, 0, 127);"">air spaces next to the stomata&nbsp;</span><br>2) As a result there is a <span style=""background-color: rgb(0, 0, 127);"">water potential gradient</span> from the <span style=""background-color: rgb(0, 0, 127);"">air spaces</span> through the <span style=""background-color: rgb(0, 0, 127);"">stomata to the air&nbsp;</span><br>3) provided <span style=""background-color: rgb(0, 0, 127);"">stomata are open</span> , water molecules <span style=""background-color: rgb(0, 0, 127);"">diffuse</span> out of the<span style=""background-color: rgb(0, 0, 127);""> air spaces</span> into the <span style=""background-color: rgb(0, 0, 127);"">surrounding air&nbsp;</span>" "Where is the <span style=""background-color: rgb(0, 0, 127);"">water lost</span> from the <span style=""background-color: rgb(0, 0, 127);"">air space</span>s replaced from in the cell?""<span style=""background-color: rgb(0, 0, 127);"">cell walls</span> of surrounding <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells&nbsp;</span>" "How do plants <span style=""background-color: rgb(0, 0, 127);"">control</span> the <span style=""background-color: rgb(0, 0, 127);"">rate</span> of <span style=""background-color: rgb(0, 0, 127);"">transpiration</span> ?""By <span style=""background-color: rgb(0, 0, 127);"">changing</span> the size of the <span style=""background-color: rgb(0, 0, 127);"">stomatal pores</span> , plants can control the rate of tranpiration." "How is <span style=""background-color: rgb(0, 0, 127);"">water lost</span> from <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells</span> ?""Water is <span style=""background-color: rgb(0, 0, 127);"">lost</span> from <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells</span> by evaporation from their <span style=""background-color: rgb(0, 0, 127);"">cell walls</span> to the <span style=""background-color: rgb(0, 0, 127);"">air spaces</span> of the leaf&nbsp;" "How is water <span style=""background-color: rgb(0, 0, 127);"">replaced</span> <span style=""background-color: rgb(0, 0, 127);"">to</span> the <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells</span> ?""This is replaced by water reaching the mesophyll cells <span style=""background-color: rgb(0, 0, 127);"">from</span> the <span style=""background-color: rgb(0, 0, 127);"">xylem</span> either via <span style=""background-color: rgb(0, 0, 127);"">cells walls</span> or via the <span style=""background-color: rgb(0, 0, 127);"">cytoplasm&nbsp;</span>" "Why does the <span style=""background-color: rgb(0, 0, 127);"">cytoplasmic route</span> occurs (water moving <span style=""background-color: rgb(0, 0, 127);"">from cytoplasm</span> to <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells</span> to <span style=""background-color: rgb(0, 0, 127);"">replace water</span> that has been <span style=""background-color: rgb(0, 0, 127);"">lost</span>) ?""- mesophyll cells lose water to the air spaces by evaporation due to <span style=""background-color: rgb(0, 0, 127);"">heat</span> supplied by the <span style=""background-color: rgb(0, 0, 127);"">sun&nbsp;</span>" "Outline/explain the process of how <span style=""background-color: rgb(0, 0, 127);"">water moves</span> throughout the <span style=""background-color: rgb(0, 0, 127);"">leaf</span> (<span style=""background-color: rgb(0, 0, 127);"">cytoplasmic route</span>) ?""1) mesophyll cells lose water to the <span style=""background-color: rgb(0, 0, 127);"">air spaces</span> by evaporation due to <span style=""background-color: rgb(0, 0, 127);"">heat </span>supplied by the <span style=""background-color: rgb(0, 0, 127);"">sun&nbsp;</span><br>2) these cells now have a<span style=""background-color: rgb(0, 0, 127);""> lower potential potential</span> and so water<span style=""background-color: rgb(0, 0, 127);""> enters</span> by <span style=""background-color: rgb(0, 0, 127);"">osmosis </span>from <span style=""background-color: rgb(0, 0, 127);"">neighbouring cells&nbsp;</span><br>3) the loss of water from these neighbouring cells<span style=""background-color: rgb(0, 0, 127);""> lowers</span> their <span style=""background-color: rgb(0, 0, 127);"">water potential</span><br>4) they, in turn , take in water from their <span style=""background-color: rgb(0, 0, 127);"">neighbours by osmosis&nbsp;</span>" "Summarise how water <span style=""background-color: rgb(0, 0, 127);"">leaves</span> the <span style=""background-color: rgb(0, 0, 127);"">cell to the atomosphere&nbsp;</span>&nbsp;?""- a <span style=""background-color: rgb(0, 0, 127);"">water potential</span> is established by <span style=""background-color: rgb(0, 0, 127);"">transport</span> of <span style=""background-color: rgb(0, 0, 127);"">water</span> around the cells of a leaf and this <span style=""background-color: rgb(0, 0, 127);"">pulls water</span> from the <span style=""background-color: rgb(0, 0, 127);"">xylem&nbsp;</span><br>- <span style=""background-color: rgb(0, 0, 127);"">across</span> the <span style=""background-color: rgb(0, 0, 127);"">leaf mesophyll</span>&nbsp;<br>- finally <span style=""background-color: rgb(0, 0, 127);"">out </span>of the <span style=""background-color: rgb(0, 0, 127);"">atmosphere&nbsp;</span>" "What is the <span style=""background-color: rgb(0, 0, 127);"">main factor</span> that is responsible for the movement of water up the <span style=""background-color: rgb(0, 0, 127);"">xylem roots</span> to the<span style=""background-color: rgb(0, 0, 127);""> leaves </span>?""This main factor is <span style=""background-color: rgb(0, 0, 127);"">cohesion-tension&nbsp;</span>" "What is the <span style=""background-color: rgb(0, 0, 127);"">process</span> of <span style=""background-color: rgb(0, 0, 127);"">movement of water</span> up the stem into the <span style=""background-color: rgb(0, 0, 127);"">xylem</span> ?""1) Water evaporates from <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells</span> due to the <span style=""background-color: rgb(0, 0, 127);"">heat</span> from the <span style=""background-color: rgb(0, 0, 127);"">sun</span> leading to <span style=""background-color: rgb(0, 0, 127);"">transpiration&nbsp;</span><br>2) water molecules form <span style=""background-color: rgb(0, 0, 127);"">hydrogen bonds</span> between <span style=""background-color: rgb(0, 0, 127);"">one another</span> and hence tends to <span style=""background-color: rgb(0, 0, 127);"">stick together</span> - known as <span style=""background-color: rgb(0, 0, 127);"">cohesion&nbsp;</span><br>3)<span style=""background-color: rgb(0, 0, 127);""> water</span> forms a<span style=""background-color: rgb(0, 0, 127);""> continuous , unbroken column</span> of <span style=""background-color: rgb(0, 0, 127);"">across</span> the <span style=""background-color: rgb(0, 0, 127);"">mesophyll cells</span> and down the <span style=""background-color: rgb(0, 0, 127);"">xylem&nbsp;</span><br>4) As water evaporates from the mesophyll cells in the leaf into the air spaces beneath the stomata , <span style=""background-color: rgb(0, 0, 127);"">more molecules</span> of water are drawn up behind it as a result of this <span style=""background-color: rgb(0, 0, 127);"">cohesion&nbsp;</span><br>5) A <span style=""background-color: rgb(0, 0, 127);"">column of water</span> is therefore <span style=""background-color: rgb(0, 0, 127);"">pulled up the xylem</span> as a result of transpiration - this is called the <span style=""background-color: rgb(0, 0, 127);"">transpiration pull</span><br>6) <span style=""background-color: rgb(0, 0, 127);"">Transpiration pull</span> puts the <span style=""background-color: rgb(0, 0, 127);"">xylem</span> under <span style=""background-color: rgb(0, 0, 127);"">tension</span> , that is there is <span style=""background-color: rgb(0, 0, 127);"">negative pressure</span> within the xylem , hence the name <span style=""background-color: rgb(0, 0, 127);"">cohesion-tension theory.</span>" "Why do plants <span style=""background-color: rgb(0, 0, 127);"">need</span> a transport system?&nbsp;""To ensure that all cells of the plant <span style=""background-color: rgb(0, 0, 127);"">receive</span> a <span style=""background-color: rgb(0, 0, 127);"">sufficient</span> amount of <span style=""background-color: rgb(0, 0, 127);"">nutrients&nbsp;</span>" "<span style=""background-color: rgb(0, 0, 127);"">What</span> does the <span style=""background-color: rgb(0, 0, 127);"">xylem</span> <span style=""background-color: rgb(0, 0, 127);"">transport</span> around the plant ?""xylem tissue enables <span style=""background-color: rgb(0, 0, 127);"">water</span> and <span style=""background-color: rgb(0, 0, 127);"">dissolved minerals</span> to travel up the plant in the <span style=""background-color: rgb(0, 0, 127);"">passive process</span> of <span style=""background-color: rgb(0, 0, 127);"">transpiration</span>&nbsp;" "What does the phloem tissue <span style=""background-color: rgb(0, 0, 127);"">do</span> and <span style=""background-color: rgb(0, 0, 127);"">transport</span> ?""Phloem tissue enables <span style=""background-color: rgb(0, 0, 127);"">all sugars</span> to reach <span style=""background-color: rgb(0, 0, 127);"">all parts</span> of the plant in the <span style=""background-color: rgb(0, 0, 127);"">active</span> process of <span style=""background-color: rgb(0, 0, 127);"">translocation&nbsp;</span>" "What is the xylem and phloem components <span style=""background-color: rgb(0, 0, 127);"">structured within</span> ?""Xylem and phloem are components of the <span style=""background-color: rgb(0, 0, 127);"">vascular bundle</span>" "what does the vascular bundle <span style=""background-color: rgb(0, 0, 127);"">provide</span> for the components (xylem and phloem) ?""Enable the <span style=""background-color: rgb(0, 0, 127);"">transport</span> of <span style=""background-color: rgb(0, 0, 127);"">substances</span> as well as provide <span style=""background-color: rgb(0, 0, 127);"">structural</span> support&nbsp;" "How are the xylem vessels<span style=""background-color: rgb(0, 0, 127);""> arranged</span> ?""They are arranged in an <span style=""background-color: rgb(0, 0, 127);"">X shape</span> in the <span style=""background-color: rgb(0, 0, 127);"">centre</span> of the vascular bundle." "<span style=""background-color: rgb(0, 0, 127);"">Why</span> is the xylem vessel <span style=""background-color: rgb(0, 0, 127);"">arranged</span> as an X shape ?&nbsp;""This enables the plant to <span style=""background-color: rgb(0, 0, 127);"">withstand</span> various <span style=""background-color: rgb(0, 0, 127);"">mechanical forces</span> such as <span style=""background-color: rgb(0, 0, 127);"">pulling&nbsp;</span>" "The X shape arrangement of xylem vessels is <span style=""background-color: rgb(0, 0, 127);"">surrounded</span> by ...""an&nbsp;<span style=""background-color: rgb(0, 0, 127);"">endodermis&nbsp;</span>" "What is the <span style=""background-color: rgb(0, 0, 127);"">function</span> of the <span style=""background-color: rgb(0, 0, 127);"">endodermis</span> ?""This is the <span style=""background-color: rgb(0, 0, 127);"">innermost</span> layer of the <span style=""background-color: rgb(0, 0, 127);"">cortex</span>; the cells are closely packed and have <span style=""background-color: rgb(0, 0, 127);"">Casparian strips</span> within their walls (water-impermeable deposits of suberin) which <span style=""background-color: rgb(0, 0, 127);"">regulate water</span> and <span style=""background-color: rgb(0, 0, 127);"">mineral uptake</span> by the roots and <span style=""background-color: rgb(0, 0, 127);"">supply</span> xylem vessels with <span style=""background-color: rgb(0, 0, 127);"">water&nbsp;</span>" "What is the <span style=""background-color: rgb(0, 0, 127);"">inner layer</span> of meristem cells <span style=""background-color: rgb(0, 0, 127);"">known </span>as ?""<span style=""background-color: rgb(0, 0, 127);"">pericycle&nbsp;</span>" "What is a <span style=""background-color: rgb(0, 0, 127);"">limitation</span> of the <span style=""background-color: rgb(0, 0, 127);"">endodermis</span> and how is this <span style=""background-color: rgb(0, 0, 127);"">overcome </span>?""- The endodermis acts as a <span style=""background-color: rgb(0, 0, 127);"">barrier</span> to the <span style=""background-color: rgb(0, 0, 127);"">free passage</span> of water and ions via the <span style=""background-color: rgb(0, 0, 127);"">apoplast (cell wall) pathway</span><br>- Water and ions must therefore cross the membrane of the<span style=""background-color: rgb(0, 0, 127);""> endodermal cell</span> and here some <span style=""background-color: rgb(0, 0, 127);"">selection of ions</span> for absorption may take place&nbsp;" "What does the <span style=""background-color: rgb(0, 0, 127);"">pericycle</span> <span style=""background-color: rgb(0, 0, 127);"">do</span> ?""It produces<span style=""background-color: rgb(0, 0, 127);""> lateral roots</span> when cells <span style=""background-color: rgb(0, 0, 127);"">here</span> divide&nbsp;" "<span style=""background-color: rgb(0, 0, 127);"">What </span>is conjunctive tissue/cortex ?""It is the tissue betwwen the xylem and phloem ; in dicots, it's made up of <span style=""background-color: rgb(0, 0, 127);"">parenchyma</span>.&nbsp;" "What is the <span style=""background-color: rgb(0, 0, 127);"">function</span> of the cortex or parenchyma within ?""This may <span style=""background-color: rgb(0, 0, 127);"">store starch</span> and can be infected by <span style=""background-color: rgb(0, 0, 127);"">Rhizobium species</span> to form <span style=""background-color: rgb(0, 0, 127);"">root nodules</span> on leguminous plants. The intracellular air spaces allows <span style=""background-color: rgb(0, 0, 127);"">diffusion of gases </span>through the root." "What is the <span style=""background-color: rgb(0, 0, 127);"">stele </span>?""All the tissues <span style=""background-color: rgb(0, 0, 127);"">inner</span> to endodermis constitute stele; here it includes <span style=""background-color: rgb(0, 0, 127);"">pericycle</span>&nbsp;,&nbsp;<span style=""background-color: rgb(0, 0, 127);"">vascular bundle ,cambium and xylem&nbsp;</span>." "What is the<span style=""background-color: rgb(0, 0, 127);""> piliferous layer</span> (also called epiblema, rhizodermis) ?""- This is an epidermis <span style=""background-color: rgb(0, 0, 127);"">modified</span> to produce root hairs.<br>- The root hairs are <span style=""background-color: rgb(0, 0, 127);"">outgrowths</span> of a single cell.&nbsp;<br>- Layer is only one cell thick , has <span style=""background-color: rgb(0, 0, 127);"">no protective function</span> hence no cuticle and is soon lost by abrasion - hence root hairs only present on <span style=""background-color: rgb(0, 0, 127);"">youngest part</span> of root.<br>- Root hairs provide <span style=""background-color: rgb(0, 0, 127);"">increased surface area</span> for uptake of water and ions in solution&nbsp;<br>" "What is cambium's <span style=""background-color: rgb(0, 0, 127);"">function</span>?""It is present in some dicotyledenous species - <span style=""background-color: rgb(0, 0, 127);"">meristematic</span> and <span style=""background-color: rgb(0, 0, 127);"">divides</span> to produce <span style=""background-color: rgb(0, 0, 127);"">new</span> phloem and xylem cells&nbsp;" "What is the <span style=""background-color: rgb(0, 0, 127);"">exodermis</span> ?""- It protects against <span style=""background-color: rgb(0, 0, 127);"">dessication</span> and <span style=""background-color: rgb(0, 0, 127);"">invasion</span> by pathogens&nbsp;<br>- May <span style=""background-color: rgb(0, 0, 127);"">replac</span>e epidermis in <span style=""background-color: rgb(0, 0, 127);"">older roots&nbsp;</span><br>- may become <span style=""background-color: rgb(0, 0, 127);"">suberized</span> and thus <span style=""background-color: rgb(0, 0, 127);"">restrict </span>water uptake to<span style=""background-color: rgb(0, 0, 127);""> younger regions </span>of the root&nbsp;<br>-Layer may be several cells<span style=""background-color: rgb(0, 0, 127);""> thick&nbsp;</span>" "<span style=""background-color: rgb(0, 0, 127);"">What does</span> the phloem do in the <span style=""background-color: rgb(0, 0, 127);"">dicotyledonous root </span>?""- <span style=""background-color: rgb(0, 0, 127);"">transport</span> of <span style=""background-color: rgb(0, 0, 127);"">organic solutes&nbsp;</span><br>- These <span style=""background-color: rgb(0, 0, 127);"">solutes </span>are <span style=""background-color: rgb(0, 0, 127);"">osmotically active</span> so phloem is situated between<span style=""background-color: rgb(0, 0, 127);""> 'arms'</span> of xylem enabling absorbed water to <span style=""background-color: rgb(0, 0, 127);"">enter xylem</span> without crossing phloem" "<span style=""background-color: rgb(0, 0, 127);"">where</span> is the pith (inner cortex)?""It is absent in mature plants but present <span style=""background-color: rgb(0, 0, 127);"">young ones</span>" "Where is parenchyma <span style=""background-color: rgb(0, 0, 127);"">found </span>?&nbsp;""In the <span style=""background-color: rgb(0, 0, 127);"">soft parts</span> of the plant - in the <span style=""background-color: rgb(0, 0, 127);"">cortex&nbsp;</span>" "What <span style=""background-color: rgb(0, 0, 127);"">type</span> of cell is parenchyma cells ?""<span style=""background-color: rgb(0, 0, 127);"">unspecialised</span> cells&nbsp;" "What is the cell wall of a parenchyma cell <span style=""background-color: rgb(0, 0, 127);"">made out of </span>and the <span style=""background-color: rgb(0, 0, 127);"">rough size</span> of the cell wall ?""The cell wall is made out of <span style=""background-color: rgb(0, 0, 127);"">cellulose</span> and it is a <span style=""background-color: rgb(0, 0, 127);"">thin cell wall&nbsp;</span>" "Are there <span style=""background-color: rgb(0, 0, 127);"">intracellular spaces</span> in parenchyma cells in the cortex ?""<span style=""background-color: rgb(0, 0, 127);"">Lots </span>of intracellular spaces are present <span style=""background-color: rgb(0, 0, 127);"">between cells&nbsp;</span>" "Are parenchyma cells l<span style=""background-color: rgb(0, 0, 127);"">iving at maturity</span> ?""<span style=""background-color: rgb(0, 0, 127);"">yes</span> it consists of living cells at maturity." "<span style=""background-color: rgb(0, 0, 127);"">Summarise</span> the <span style=""background-color: rgb(0, 0, 127);"">main functions</span> of parenchyma cells ?"- Photosynthesis<br>- Food storage&nbsp;<br>- Gas exchange&nbsp; "<span style=""background-color: rgb(0, 0, 127);"">Where</span> is collenchyma cells found ?""- in the petiole, leaves and young stems&nbsp;<br>- <span style=""background-color: rgb(0, 0, 127);"">near</span> the epidermis&nbsp;" "What <span style=""background-color: rgb(0, 0, 127);"">type</span> of cells are collenchyma cells ?""<span style=""background-color: rgb(0, 0, 127);"">specialised</span> cells&nbsp;" "What is the collenchyma cell wall <span style=""background-color: rgb(0, 0, 127);"">made out</span> of and the <span style=""background-color: rgb(0, 0, 127);"">rough size</span> of it ?""- Made out of <span style=""color: rgb(242, 242, 242); background-color: rgb(0, 0, 127);"">extra cellulose</span> and pectin&nbsp;<br>- and it is an <span style=""background-color: rgb(0, 0, 127);"">unequally thin cell wall&nbsp;</span>" "<span style=""background-color: rgb(0, 0, 127);"">How much</span> <span style=""background-color: rgb(0, 0, 127);"">intracellular space </span>is there in collenchyma cells ?""- <span style=""background-color: rgb(0, 0, 127);"">little</span> intracellular space&nbsp;" "<span style=""background-color: rgb(0, 0, 127);"">Does</span> collenchyma cells consist of <span style=""background-color: rgb(0, 0, 127);"">living cells at maturity</span> ?"Yes&nbsp; "What is the <span style=""background-color: rgb(0, 0, 127);"">function</span> of collenchyma cells ?""- It provides <span style=""background-color: rgb(0, 0, 127);"">mechanical support</span> to the plant&nbsp;<br>- Especially in <span style=""background-color: rgb(0, 0, 127);"">young stem</span>s as they are living cells and can expand as the <span style=""background-color: rgb(0, 0, 127);"">stem grows</span>" "Where is Sclerenchyma <span style=""background-color: rgb(0, 0, 127);"">found</span> ?""- found in mature parts of the plant&nbsp;<br>- In <span style=""background-color: rgb(0, 0, 127);"">vascular bundles&nbsp;</span>" "What<span style=""background-color: rgb(0, 0, 127);""> type</span> of cell is sclerenchyma cells?""<span style=""background-color: rgb(0, 0, 127);"">specialised</span> cells&nbsp;" "What is the cell wall <span style=""background-color: rgb(0, 0, 127);"">made out of</span> in Sclerenchyma cells and what is the <span style=""background-color: rgb(0, 0, 127);"">rough size</span> ?""- Cell wall made of <span style=""background-color: rgb(0, 0, 127);"">lignin</span><br>- <span style=""background-color: rgb(0, 0, 127);"">Thick</span> and <span style=""background-color: rgb(0, 0, 127);"">rigid</span> cell wall" "Does sclerenchyma cells have any <span style=""background-color: rgb(0, 0, 127);"">intracellular space</span> ?""<span style=""background-color: rgb(0, 0, 127);"">No</span> , it does not have any intracellular space" "<span style=""background-color: rgb(0, 0, 127);"">Does</span>&nbsp;sclerenchyma cells consist of living cells at maturity ?""No , it consists of <span style=""background-color: rgb(0, 0, 127);"">dead cells</span> at maturity" "What is the <span style=""background-color: rgb(0, 0, 127);"">function</span> of Sclerenchyma cells ?"- Provides mechanical support&nbsp;<br>- protection&nbsp;<br>- Transport substances&nbsp; "Explain how the <span style=""background-color: rgb(0, 0, 127);"">structure</span> of Sclerenchyma contributes to why it has <span style=""background-color: rgb(0, 0, 127);"">no living contents </span>?""- They are <span style=""background-color: rgb(0, 0, 127);"">elongated</span> into supporting fibres&nbsp;<br>- Therefore have <span style=""background-color: rgb(0, 0, 127);"">heavily lignified cell walls </span>and thus have no living contents." "What does the<span style=""background-color: rgb(0, 0, 127);""> epidermis</span> do in the <span style=""background-color: rgb(0, 0, 127);"">herbaceous stem</span> ?""- <span style=""background-color: rgb(0, 0, 127);"">protects </span>the moist inner tissues of the stem against dessication and invasion of pathogens&nbsp;<br>- Epidermis also contributes to <span style=""background-color: rgb(0, 0, 127);"">suppor</span>t by holding in the turgid parenchyma cells of the cortex&nbsp;" "How does the <span style=""background-color: rgb(0, 0, 127);"">structure</span> of the epidermis in the herbacious stem contribute to <span style=""background-color: rgb(0, 0, 127);"">another</span> function ?""The epidermis is typically <span style=""background-color: rgb(0, 0, 127);"">one cell thick</span> and may have extended <span style=""background-color: rgb(0, 0, 127);"">unicellular</span> or <span style=""background-color: rgb(0, 0, 127);"">multicellular</span> hairs which (a) <span style=""background-color: rgb(0, 0, 127);"">reduce air movement</span> and water loss and (b) <span style=""background-color: rgb(0, 0, 127);"">reflect light </span>and prevent overheating." "What does the <span style=""background-color: rgb(0, 0, 127);"">cambium do</span> in the <span style=""background-color: rgb(0, 0, 127);"">herbaceous stem</span> ?""- a lateral meristem&nbsp;<br>- Simple , <span style=""background-color: rgb(0, 0, 127);"">non-specialised cells divide </span>and then <span style=""background-color: rgb(0, 0, 127);"">differentiate</span> into phloem (to outside) and xylem (to inside)&nbsp;" "<span style=""background-color: rgb(0, 0, 127);"">What</span> is a protoxylem in the <span style=""background-color: rgb(0, 0, 127);"">herbacious stem </span>?""- <span style=""background-color: rgb(0, 0, 127);"">incomplete</span> lignification - may have <span style=""background-color: rgb(0, 0, 127);"">cytoplasm&nbsp;</span>" "<span style=""background-color: rgb(0, 0, 127);"">What</span> is the <span style=""background-color: rgb(0, 0, 127);"">metaxylem </span>in the herbacious stem ?""<span style=""background-color: rgb(0, 0, 127);"">Heavy lignified</span> secondary cell wall - no living contents&nbsp;" "Water moves through the xylem , which <span style=""background-color: rgb(0, 0, 127);"">features</span> of the xylem support and aid that ?""- They transport water and minerals , and also serve to provide <span style=""background-color: rgb(0, 0, 127);"">structural support&nbsp;</span><br>- They are <span style=""background-color: rgb(0, 0, 127);"">long cylinders</span> made of<span style=""background-color: rgb(0, 0, 127);""> dead tissue </span>with <span style=""background-color: rgb(0, 0, 127);"">open ends</span> , therefore they can form a <span style=""background-color: rgb(0, 0, 127);"">continuous column&nbsp;</span><br>- xylem vessels also contain <span style=""background-color: rgb(0, 0, 127);"">pits</span> which enable water to <span style=""background-color: rgb(0, 0, 127);"">move sideways</span> <span style=""background-color: rgb(0, 0, 127);"">between</span> the <span style=""background-color: rgb(0, 0, 127);"">vessels&nbsp;</span><br>- They are <span style=""background-color: rgb(0, 0, 127);"">thickened</span> with a tough substance called <span style=""background-color: rgb(0, 0, 127);"">lignin</span>, which is deposited in <span style=""background-color: rgb(0, 0, 127);"">spiral patterns</span> to enable the plant to <span style=""background-color: rgb(0, 0, 127);"">remain flexible</span>." Describe transpiration briefly ?"Transpiration is the process where plants <span style=""background-color: rgb(0, 0, 127);"">absorb water from the roots</span> , which then <span style=""background-color: rgb(0, 0, 127);"">moves up</span> through the plant and is <span style=""background-color: rgb(0, 0, 127);"">released</span> into the <span style=""background-color: rgb(0, 0, 127);"">atmosphere</span> as <span style=""background-color: rgb(0, 0, 127);"">water vapour</span> through <span style=""background-color: rgb(0, 0, 127);"">pores</span> in the <span style=""background-color: rgb(0, 0, 127);"">leaves</span>.Carbon dioxide <span style=""background-color: rgb(0, 0, 127);"">enters</span> , while water and oxygen <span style=""background-color: rgb(0, 0, 127);"">exit </span>through a leaf's <span style=""background-color: rgb(0, 0, 127);"">stomata</span>&nbsp;" "Why is the transpiration stream <span style=""background-color: rgb(0, 0, 127);"">important</span> which is movement of water up the stem ?""- It enables processes such as <span style=""background-color: rgb(0, 0, 127);"">photosynthesis, growth and elongation</span> as it supplies the plant with water which is <span style=""background-color: rgb(0, 0, 127);"">neceasary for all of these processes</span>.<br>- Apart from this, the transpiration stream supplies the plant with the required minerals , whilst enabling it to <span style=""background-color: rgb(0, 0, 127);"">control its temperature</span> via evaporation of water.<br>" "How does <span style=""background-color: rgb(0, 0, 127);"">wind speed</span> <span style=""background-color: rgb(0, 0, 127);"">increase</span> the rate of transpiration ?""- The air is more <span style=""background-color: rgb(0, 0, 127);"">saturated</span><br>- steeper concentration <span style=""background-color: rgb(0, 0, 127);"">gradient&nbsp;</span><br>-therefore <span style=""background-color: rgb(0, 0, 127);"">faster/greater diffusion&nbsp;</span>" "Suggest what the student would need to do in order to get a <span style=""background-color: rgb(0, 0, 127);"">valid comparison</span> of the <span style=""background-color: rgb(0, 0, 127);"">rates of transpiration</span> of the <span style=""background-color: rgb(0, 0, 127);"">two species</span> ?""- same <span style=""background-color: rgb(0, 0, 127);"">conditions</span><br>- calculate the <span style=""background-color: rgb(0, 0, 127);"">rate per unit of time</span> - how ? - draw round leaf on graph paper&nbsp;<br>- picked at the <span style=""background-color: rgb(0, 0, 127);"">same time</span> or <span style=""background-color: rgb(0, 0, 127);"">same degree of turgidity</span>&nbsp;" "Describe how the apparatus of transpiration should be set up to ensure <span style=""background-color: rgb(0, 0, 127);"">valid meaurements</span> can be obtained ?""- The apparatus is inserted <span style=""background-color: rgb(0, 0, 127);"">underwater&nbsp;</span><br>-There are no <span style=""background-color: rgb(0, 0, 127);"">EXTRA</span> air bubbles in the apparatus&nbsp;<br>- use vaseline to ensure <span style=""background-color: rgb(0, 0, 127);"">air/water-tight joints&nbsp;<br>- use a healthy leaf&nbsp;</span><br>-cut the shoot at a <span style=""background-color: rgb(0, 0, 127);"">slant</span> underwater&nbsp;<br>- conditions are the <span style=""background-color: rgb(0, 0, 127);"">same</span>&nbsp;<br>- <span style=""background-color: rgb(0, 0, 127);"">dry </span>off leaves&nbsp;<br>- time to <span style=""background-color: rgb(0, 0, 127);"">acclimatise</span> before taking a <span style=""background-color: rgb(0, 0, 127);"">reading&nbsp;</span><br>" "Transpiration itself is not measured by the potometer.State <span style=""background-color: rgb(0, 0, 127);"">precisely</span> what is measured by using the apparatus ?""- rate of <span style=""background-color: rgb(0, 0, 127);"">WATER UPTAKE as a result of water loss from the plant&nbsp;</span>" "How does <span style=""background-color: rgb(0, 0, 127);"">light intensity </span>increase the rate of transpiration ?""- More light means there is <span style=""background-color: rgb(0, 0, 127);"">more stomata open</span> and and therefore and <span style=""background-color: rgb(0, 0, 127);"">increased surface area </span>for transpiration&nbsp;<br>- <span style=""background-color: rgb(0, 0, 127);"">faster diffusion</span> of water vapour from the stomata&nbsp;" "How does<span style=""background-color: rgb(0, 0, 127);""> temperature</span> increase the rate of transpiration ?""- higher temperature&nbsp;<br>- more evaporation (increase <span style=""background-color: rgb(0, 0, 127);"">water vapour concentration</span>) and therefore <span style=""background-color: rgb(0, 0, 127);"">more kinetic energy&nbsp;</span><br>- <span style=""background-color: rgb(0, 0, 127);"">Faster diffusion</span> of water vapour from the stomata&nbsp;" "How does <span style=""background-color: rgb(0, 0, 127);"">humidity</span> increase the rate of ranspiration ?""- less humidity meand <span style=""background-color: rgb(0, 0, 127);"">less water vapour</span> in the <span style=""background-color: rgb(0, 0, 127);"">surrounding air</span> and therefore an <span style=""background-color: rgb(0, 0, 127);"">increase in water vapour concentration gradient&nbsp;</span><br>- <span style=""background-color: rgb(0, 0, 127);"">faster diffusion</span> of water vapour out of the stomatal pore" What is a potometer ?"an apparatus used to <span style=""background-color: rgb(0, 0, 127);"">measure the rate of transpiration&nbsp;</span>" How does transpiration occur ?"- <span style=""background-color: rgb(0, 0, 127);"">moist lining </span>of spongy mesophyll cells <span style=""background-color: rgb(0, 0, 127);"">evaporate</span> forming water vapour&nbsp;<br>- water vapour builds up in <span style=""background-color: rgb(0, 0, 127);"">air spaces&nbsp;</span><br>- If water vapour concentration is <span style=""background-color: rgb(0, 0, 127);"">high</span> enough and stomata is open , water vapour <span style=""background-color: rgb(0, 0, 127);"">diffuses out&nbsp;</span>" "What is the <span style=""background-color: rgb(0, 0, 127);"">principle</span> of the potometer ?""- as transpiration occurs from the leaves the plant will <span style=""background-color: rgb(0, 0, 127);"">pull up</span> more water from the potometer by <span style=""background-color: rgb(0, 0, 127);"">cohesion-tension</span> causing the bubble t<span style=""background-color: rgb(0, 0, 127);"">o move towards the plant&nbsp;</span><br>- the more water lots by transpiration , the <span style=""background-color: rgb(0, 0, 127);"">more water taken up</span> , the<span style=""background-color: rgb(0, 0, 127);""> further the bubble moves&nbsp;</span>" "Describe the <span style=""background-color: rgb(0, 0, 127);"">movement</span> of water <span style=""background-color: rgb(0, 0, 127);"">from </span>the <span style=""background-color: rgb(0, 0, 127);"">soil </span>to the<span style=""background-color: rgb(0, 0, 127);""> root hair</span> ?""- uptake of water - water moves into root hairs via <span style=""background-color: rgb(0, 0, 127);"">osmosis</span> down a water potential gradient (passive)&nbsp;<br>- root hairs provide a<span style=""background-color: rgb(0, 0, 127);""> maximum surface area</span> for maximum absorption of water&nbsp;<br>- the uptake of minerals <span style=""background-color: rgb(0, 0, 127);"">by active transport</span> takes place at the<span style=""background-color: rgb(0, 0, 127);""> same time (otherwise it would be less efficient)</span>&nbsp;and reduces the water potential in the <span style=""background-color: rgb(0, 0, 127);"">cell cytoplasm</span> so water is continuously taken up by osmosis&nbsp;" The epidermis of the roots contains ....root hair cells&nbsp; Describe the movement of root hair to xylem ?"1) Water taken up by root hairs crosses the root cortex&nbsp;<br>- water moving through cell walls of neighbouring cells <span style=""background-color: rgb(0, 0, 127);"">- apoplastic pathway</span><br>- water moving from plasmodesmata to cytoplasms from cell to cell - <span style=""background-color: rgb(0, 0, 127);"">symplast and vacuolar pathway ( through plasma membrane and plasmodesmata to cytoplasms from cell to cell , vacuolar is the same , but also through vacuoles)</span><br>2) water moves from one cell to another till it reaches the xylem; movement is due to concentration gradient due to concentrated sap vacuole of cells&nbsp;<br>- <span style=""background-color: rgb(0, 0, 127);"">down concentration gradient </span>therefore more <span style=""background-color: rgb(0, 0, 127);"">negative&nbsp;</span><br>-<span style=""background-color: rgb(0, 0, 127);""> water crosses the membrane</span>&nbsp;<br>- pits in xylem - <span style=""background-color: rgb(0, 0, 127);"">aquaporins</span>" "Why can the <span style=""background-color: rgb(0, 0, 127);"">apoplast pathway</span> not be used to reach the <span style=""background-color: rgb(0, 0, 127);"">parenchyma cells</span> ?""- The apoplastic pathway is <span style=""background-color: rgb(0, 0, 127);"">stopped at the endodermis</span> due to cells in it haveing a <span style=""background-color: rgb(0, 0, 127);"">band of suberin</span> forming the <span style=""background-color: rgb(0, 0, 127);"">casparian strip</span> ( an impenetrable barrier to water)&nbsp;<br>- <span style=""background-color: rgb(0, 0, 127);"">suberin deposits</span> increase with <span style=""background-color: rgb(0, 0, 127);"">age of cells</span> except for certain passage cells (such as vacuolar and symplats pathways)&nbsp;<br>- <span style=""background-color: rgb(0, 0, 127);"">water can pass freely</span> through these <span style=""background-color: rgb(0, 0, 127);"">passage cells&nbsp;</span>" "Summarise what is <span style=""background-color: rgb(0, 0, 127);"">root pressure</span> ?""- minerals move into the xylem by active transport <span style=""background-color: rgb(0, 0, 127);"">forcing water</span> into the xylem and pushe sit up to the stem&nbsp;" "Summarise what is <span style=""background-color: rgb(0, 0, 127);"">transpiration pull</span> ?""- loss of water at the leaves <span style=""background-color: rgb(0, 0, 127);"">replaced</span> by water moving up the xylem&nbsp;" Summarise what is cohesion-tension theory ?"- <span style=""background-color: rgb(0, 0, 127);"">cohesion </span>between <span style=""background-color: rgb(0, 0, 127);"">H2O molecules&nbsp;<br>- tension </span>in column of water - which is why xylem is strenghtened by lignin so the <span style=""background-color: rgb(0, 0, 127);"">whole column of water is pulled up in one chain&nbsp;</span>" "summarise what is <span style=""background-color: rgb(0, 0, 127);"">capillary action</span> ?""<span style=""background-color: rgb(0, 0, 127);"">adhesion</span> of water molecules to xylem as they are narrow - hydrogen bonding to OTHER&nbsp; molecules such as the <span style=""background-color: rgb(0, 0, 127);"">WALLS&nbsp;as well as water molecules&nbsp;</span>" "Summarise the <span style=""background-color: rgb(0, 0, 127);"">importance of transpiration</span> ?""- <span style=""background-color: rgb(0, 0, 127);"">support</span> turgid cells&nbsp;<br>-for <span style=""background-color: rgb(0, 0, 127);"">cell growth</span><br>- enables <span style=""background-color: rgb(0, 0, 127);"">mineral ions</span> to be taken up&nbsp;<br>-<span style=""background-color: rgb(0, 0, 127);"">cooling</span> the plant&nbsp;<br>- for <span style=""background-color: rgb(0, 0, 127);"">photosynthesis</span>"
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