Bio Unit 1


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  • Created by: Jamie
  • Created on: 19-12-11 18:12

Cell Divison- Mitsosis

What is the cell cycle? When does the cell cycle start? When does it end? What phase does the cell grow? What phase do cells divide? What period is longer? What does the cell carry out in Interphase? What does it prepare to do? What happens to the cell’s DNA? What is also replicated? Why? What happens to ATP content? Why? What happens if errors are detected in the genetic material? What does this prevent? 

Order the phases? At Prophase what happens to the chromsomes? What are centrioles? What do they start to do? What do they form? What’s it called? What happens to the nuclear envelope? What happens to the chromsomes? When mitosis begins what are chromsomes made up of?  What are they joined by? What are the separate strands called? Why are their two strands? What do the chromatids end up as when mitosis is over?

At metaphase what do the chromsomes do? What do they attach to? By what? What are the centromers on? At Anaphase what happen to the centromeres? What seperates? What does the spindle do? What does it pull?

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The process that all body cells from mutlicelluar organism use to grow and divde,when a cell has been produced by cell division, with the cell dicing to produce two identical cells, Interphase and Mitosis, Interphase, genetic material is copied and checked for any errors from copying, prepares to divide, unravel;ed and replicated to double the gentic content, organlelles, so it has spare ones, is increased as it provides the energy for cell divison, the cell may kill itself so it prevents any mutuation in the DNA being passed on

Interphase, Prophase, Metaphase, Anaphase, Telophase, they condense getting shorter and fatter, tiny bundles of protein, they start moving to opposite ends of the cell, forming a network of protein fibres across it, spindle, it breakds down, lie free in the cytoplasm, of two strands joined in the middle by a centromere, chromatids, because eacg chromosome has already made an identical copy of itself during interphase, end up as one-strand chromsomes in the new daughter cell

Line up along the middle of the cell, to the spindle by the centromere, spindle equator, they divide separating each pair of sister chromatids, contracts pulling chromatids to opposite ends of the cell,

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Cell Divison Mitosis

At telophase what do the chromatids reach? What do they do their? What are they called now? What forms around each group of chromsoomes? What are their two of now? What divides? What are their two of now? What are they identical to? Whats finished? What does each daughter cell start? 

How can you see chromosmes under a microscope? What can you watch? Learn how to idenifty stages from pics?

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The opposite poles on the spindle, they uncoil and become long and thing again, chromosomes, nuclear envolpe, two nuclei, the cytoplasm making two daughter cells , genetically identical to the original cell and to each other, Mitosis, interphase, 

Stain chrosomes, the stages of mitosis

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Cell Division and Reproduction

What does it mean to reproduce asexually? What sort of organism do this? What do they use? What does this mean for the new organisms produced?

What type of microgorganism is yeast? What are they a type of? Are they eukaryotic or prokaryotic? What do they have all the usual of? Wheres the chromosomes? How can they reproduce? Whats the process called? What does budding involve? What does this mean for the offspring? What happens first and where? What phase does it undergo first? What happens here? What does it undergo next? What complete? What does the budding cell contain? What happens finally? Whats produced? 

Give two example of two gametes? What happens in sexual reproduction? Whats it called when two gametes join? What do they form? What does the zygote do? What is meiosis a type of? Where does it happen? What does it produce? Do cells that divide by meisosis have the full numer of chromsomes to start with? What about the cells that are formed from meisosis? What are cells formed by meiosis like? Why? 

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To reproduce without sex, plants and fungi, mitosis, are genetically identical to the original (parent organism

Single-celled, fungi, eukaryotic, all the usual organelles, in a nucleus, asexually, budding, mitosis, they are genetically identical to the parent cell, a bud forms at the durface of the cell, interphase, the DNA and organelles are replicated, mitosis, nuclear divison, contains ta nucleus that has an identical copy of the parents cell DNA, the bud seperates, producing a genetically identical yeast cell0

Egg and sperm, two gametes join together, fertilisation, zygote, divides and develops into a new organism, a type of cell divison that happens in the reproductive organs to produce gametes, full number, half the number, genetically different because each new cell ends up with a different combination of chromosomes

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Cell Divison Reproduction

In meiosis what does the DNA do first? What do they do next? How many chromosomes do humans have? How many pairs? Where does one chrosome in each pair come from? The chromosome in a pair are the same how? Whats different? What are they called? What are these pairs called? What do the chromatids do? What do they have new of now? What happened to these pairs in the first divison? Where can any chromosome go? As long as what? What happens in the second divison? Whats produced? Why are they genetically different from each other?   

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Replicates and coils up to form chromosomes, the chromosomes arrange themselves into homologous pairs, 46, 23, one from mum and one from dad, they are the same size and have the same genes, they could have different versions of those genes, alleles, homologous pairs, chromatids of one chromosome swap bits of another chromatid, now have a new combination of allelles, split up, they can go into either cell as long as each cell gets a number 1 etc, splits in half, any half into any cell, four new genetically cells are produced, because the chromosomes swap bits during meisosis and each gamete gets a combination of half of them at random 

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Stem Cells and Differentiation

What are multicellular organisms made up from? Examples? Where do all specialised cells originally come from? Are stems cells specialised? Why? Where have all multicellular organisms come from? Where are stem cells found in humans? Why embryos? Where in adults are they found? Whats wrong with them though? Why?

Why do stem cells divide? Which become what? Define differentiation? What are stem cells used for in adults? Example? What are they used for in plants? Why are they always needed in plants? Give two examples stem cells can become in plants? What are bones? What do they contain? What do the main bones of the body have in the centre? What happens here? Whats the technical term for red  and white blood cells? Where are stem cells found in plantS? Wheres cambium found? What do they divide to become? What does the vascular cambium form? Where? What do the cells do as they move away from cambium?

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Made up from many different cell types that are specilaised for their function, liver cells muscle cells whiteblood cells, stem cells, they are unspecialised as they can develop into any type of cell, stem cells, early embryos and few places in adults, in the first few days of an embryos life any of its cells can devlop into any type of human cell- they are all stem cells, bone marrow but theyre not as flexble as they are limited in range of what cells they can develop into

To become new cells, which become speciliased, the process by which a cell becomes specialised for its job, adult stem cells are used to replace damaged cells like to make new skin or blood cells, to make new shoots and root as they are always growing throughout their lives, xylem and phloem, are living organs containing nerves and blood vessels, marrow, adult stem cells divide ad differentiate to replace worn out blood cells, eryhtocytes and neutorphils, cambium, root and stem, xylem and phloem, a ring inside roots and shoots, differentiate as they move away

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Stems Cells and Differntiation

Once a cells differietniated what does it have? Whats adapted to perform that function? Whats a neutrophil? What do they do? What allows them to enguldf foreign particls or pathogens? What do they have many of to break down the engulfed particles? How? Whats an Erythocyte? What do they do? Whats its shape called? What does it provide? For what? What don’t they have? What does this allow? What do Epithelial cells cover? What are they joined by? What do some eptihelia have? Example of where? What do they do? What do other epithelia have? Example of where? What are they? What does it give the cell? What do sperm cells have? For what? What do they have a lot of? Why? Whats the acrosome? What does it contain? Why? 

Where can you find palisade mesophyll cells? What do they do most of? What do they contain many of? Why? What are the walls like? Why? What do root hair cells do? What do they have large of? For what? Whats the wall like? For what? What does it have extra of? Why? What do Guard cells line? Whats stomata? What do guard cells take up in the light? What do they become? Whats their outer walls like? Whats their inner walls like? What does this cause? What process does this allow?

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They have a specific function, structure, White blood cell, they defend the body against disease, their flexible shape, lysosomes in their cytoplasm, lysosomes conain digestive enzymes to break them down, Red blood cells, carry oxygen in the blood, biconcave disc shape, provides a large surface area for gas exchange, a nucleus, allows more room for haemoglobin, cover the surface of organs, joined by interlinking cell membranes and a membrane at their base, cilia in the lungs, that beat to move particles away, microvilli in the small intestine, they are folds in the cell membrane that increase surface area, a flagellum so they can swim to the egg, mitochondria to provide the energy to swim, is the head and it contains digestive enzymse to enable the sperm to penetrate the surface of the egg, 

Leaves, photsyntheiss, many chloroplasts, so they can absorb sunlight, walls are thin so carbon dioxide can diffuse out easily, they absorb water and minerals from soil they have a large surface area for absorbtion, thin permeable cell wall for water and ion entry, extra mitochondria to provide the energy needed for active transport, line the stomata, the tiny pores in the surface of the leaf used for gas exchange, guard cells take up water and become rigid, thin outer walls and thicker inner walls force them to bend outwards, opening the stomata, it allows leaves to exchange gases for photosynthesis

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Tissues, Organs and Systems

What is tissue made up of? Plus what? Are they specialised? To do what? Does it consist of more than one cell type? What is squamous epithelium tissue? Name two places its found? Whats ciliated epithelium? Wheres it found? Example? What do they do here? Whats xylem tissue? What does it do? What does it contain? What do they do? What does phloem tissue do? How it arranged? Whats it made up of? What does each sieve cell have? Why? What are the end walls called?

Whats an organ? Give a human example? What do they contain? Where? What else? Where? What do they also have? Where? Give a plant example? What do they contain? For  what? As well as ? and what where?

Organs working together form what? What does each system have? Give one example? Whats it made up of involved in what process?  Name the organs that are part of the respiratory system? Whats another organ system example? What are the organs their involved in? name them?

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A group of cells plus any extracellular material secreted by them, they ar especiliasedd to work together to carry out a particular function, it can contain more than one cell type, is a single layer of flat cells lining a surface, alveoli and the lungs, is a layer of cells covered in cilia, its found on surfaces where things need to be moved, trachea where they waft waft mucus along, is a plant tissue with two jobs, it transports water around the plant and it supports the plant, xylem vessel cell which thickens the wall perforated by pits and parenchyma cells which fill in gaps between vessels, transports sugars around the plant, arranged in tubes and made up of sieve cells, companion cells and some ordinary plant cells, end walls with holes in them allowing sap to move easily through them, sieve plates

Is a group of different tissues that work together to perform a particular function, the lungs, they contain squamous epithelium tissue found in the alvoli and ciliated epithelium tissue in the bronchi, elastic connective tissue and vascular tissue in the blood vessels, leaves, they contain palisade tissue for photosynthesis as well as epidermal tissue and xylem and phloem tissues in the veins 

Organ Systems, a particular function, respiratory system, is made up of all the organs, tissue and cells involved in breathing, lungs, trachea, larynx, nose, mouth and diaphragm, Circulatory system made up of all the organs involved in blood supply, hear, arteries, veins and capillaries are all part of this system

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Tissues, Organs and Systems

Why do multicellular organisms work efficiently? Whats the advantage? What cant specialised cells do? What depends on what? What does this mean has to happen? Give an example? Whats it good at? Whats it not ogod? What does it depend on? Give another example? What are they good at? What do they need? What do they depend on? What have multicellular organisms developed? Name one? What is it used for? Give an example in plants? Give an example in humans? Name the other one? What do they allow? What do both plants and animals have? What do animals also have?

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They have different cells specialised for different functions, each different cell type can carry out its specialised function more effectively than an unspecialised cell could, they can do everything on their own, each cell type depends on other cells for the functions it can carry out, the cells, tissues and organs within multicellular organisms must cooperate with each other to keep the organism alive and running, a palisade cell is good at photosynthesis but not absorbing water and minerals from soil so it depends on root hair cells and vice versa, muscle cells are good for getting you where you want to go but they need oxygen so they depend on erythrocytes to get them from the lungs, different systems of co-operation between different cells, Transport systems, its used to carry substances between the different cells for example xylem cells carry water and minerals from the root hair cells to the palisade cells and phloem cells carry sugars around the plant, in humans the circulatory system helps to move substances around the body in the blood, Communication Systems, these allow communication between cells in different parts of the organism, both plants and animals have chemical communication systems that use messenger molecules such as hormone, animals also have nervous systems for communication by sending electrical signals to different tissues and organs

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Xylem and Phloem

What substances do plant cells need? What do they need to get rid of? Are plants multicellular? What does this mean they have just like animals? How could plants exchange substances? Whats this mean? Why don’t they? What do plants need then? To do what? What way?

What does xylem tissue transport? What does phloem tissue transport? Example? Where are xylem and phloem found? Where do they transport to? What does where they are found connected to? Which is? Where are xylem and phloem found in the root? What does it provide? Where in the stem? To provide? What do they make up in the leaf? What do they support? Draw root, stem and leaf cross-section with labels of xylem and phloem?

What is xylem? What’s it made up of? What is the part of xylem that actually transports? Whats the xylem vessel shape? What are they formed from? How are they joined? What don’t they have? What does this allow? What are the cells like? What does this mean they don’t contain? What are their walls thickened with? What’s this called? What does this support and prevent? When does the lignin increase? What does the water and ions move in and out of in the vessel? What don’t they have?

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Water minerals and sugars, waste substances, they are multicellular so they have a small surface area:volume ratio, direct diffusion, from the outer surface, it would be to slow, transport systems to move substances to and from individual cells quickly

Water and mineral ions, dissolved substances like sugars, throughout the plant, to all parts of the plant, is connected to xylems other function, support, in the centre to provide support for the root as it pushes through the soil, near the outside to provide a sort of scaffolding that reduces bending, a network of veins which support the thin leaves

Is a tissue, several different cell types, xylem vessels, long, tube-like structures, formed from cells called vessel elements, joined end to end, they have no end walls on these cells, it makes an uninterrupted tube that allows water to pass up through the middle easily, dead so they have no cytoplasm, their walls are thickened with a woody substance called lignin, it helps support the xylem vessel and stops them collapsing inwards, as the cell gets older, through small pits in the walls where there’s no lignin

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Xylem and Phloem

What does phloem tissue transport? Give examples? Give an example of sugar? Like xylem what is phloem formed from? How is it unlike xylem? What four things does phloem tissue contain? What are the most important two for transport? What are sieve tube elements? What do they form? For what? How are they joined? To form what? What’s the sieve part? What do they have? To allow what? What’s unusual about sieve tube elements for living cells? How is the cytoplasm connected? What does the lack of nucleus and organelles mean for the sieve tube elements? What does every sieve tube element have instead? What do companion cells carry out? For what? Give an example? 

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Solutes (dissolved substances) mainly sugars like sucrose, its formed from cells arranged in tubes, phloem is purely a transport tissue it doesn support at all, phloem fibres phloem parenchyma sieve tube elements and companion cells, sieve tube elements and companion cells, They are living cells that form the tube for transport solutes through the  plant, they are joined end to end sieve tubes, the end walls which have lots of holes in them to allow solutes to pass through, no nucleus a very thin layer of cytoplasm and few organelles, the cytoplasm of adjacent cells are connected through the holes in the sieve plates, means they cant survive on their own, a companion cell, carry out the living functions for both themselves and their sieve cell, they provide energy for the active transport of solutes

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Water Transport

Where does the water have to get from? Through what? Into what? To be transport where? Where does water enter? What does it pass through? What does this include? To reach what? What is water drawn into the roots down? What areas does water always from to areas of what? Meaning it goes down what? What water potential does soil have? Meaning? What water potential does leaves have? Why? What does this create? From where to where? 

What does water travel through the roots via? Into the what? What are the two paths? What does the symplast pathway go through? Example? What does the cytoplasm of neighbouring cells connect through? What are they? Which pathway goes through the non-living parts of the cell? Example? What are the walls like? What can water do easily? As well as?   

What happens when water in the apoplast pathway gets to the endodermis cells in the root? By what? In what? Called what? What pathway does it take then? Why is it useful? Whats good about it going through the cell membrane? Where does it go after this barrier? Which is the main pathway out of these two? Why? 

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The soil, through the root and into the xylem to be transported around the plant, through the root hair cell and then passes through the root cortex including the endodermis to reach the xylem, down a water potential gradient, areas of higher water potential to lower water potential, it goes down a water potential gradient, high water potential meaning theres lots if water, lower water potential because water constantly evaporates from them, a water potential gradient that keeps water moving through the plant in the right direction, from roots to leaves

Root cortex, xylem, apoplast pathway and the symplast pathway, the living part of the cell i.e. cytoplasm, connects through plasmodesmata, small gaps in the cell walls, the apoplast pathway, the cell walls, they are very absorbent and water can simply diffuse through them, passing through the spaces between them

Its path is blocked by a waxy strip in the cell walls called the casparian strip, symplast pathway, because it has to go through a cell membrane, because cell membranes are able to control wether or not substances in the water get through,  xylem

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Water Transport

Where does the xylem vessel transport to? what does water do at the leaves? By what pathway? How does water leave the cell walls? Into what? What are the stomata? What happens when they open? Down what? Into what? Whats this loss o water from a plans surfaced called?

What is the movement of water from roots to leaves called? What are the three mechanisms that water called? What do cohesion and tension help? Against what? Where does wayer evaporate from the leaves? by what? what does this create? Whats this like? What does it pull? What are water molecules like? Meaning? What does this mean? What does water enter the stem through? What is adhesion responsible for? As well as being attracted to each other what are water molecules also attracted to? what does this help?

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All around the plant, water leaves the xylem and moves into the cells mainly by the apoplast pathway, evaporation from the cell walls into the spaces between cells in the leaf, tiny pores in the surface of the leaf, the water moves out of the leaf down the water potential gradient into the surrounding air, transpiration

Transpiration stream, cohesion tension and adhesion, help water move up plants from roots to leaves against the force of gravity, a the top of the xylem, transpiration, a tension i.e. a suction, which pulls more water into the leaf, are cohesive meaning they stick together, so when some are pulled into the leaf other follow meaning the whole column of water in the xylem from the leaves down to the roots move upwards, root cortex cells, the movement of water, are attracted to the walls of the xylem vessel which helps water to rise up through the xylem vessel

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What is transpiration? Especially where? Whats it a result of? What does a plant need to open? Why? So it can what? via what? What does this let out? Wheres the higher concentration of water inside the leaf or in the air? So where does water move? Down the what? when what opens? What does this mean transpiration is?   

What do temp, humidity and wind alter? Whats different? If its lighter whats the transpiration rate? Why? The higher the temp the what the transpiration rate? What do warmer water molecules have? What does this mean for evaporation? What does this increase? Causing what? the lower the humidity the what the transpiration rate? What happens to the water potential gradient if the air around the plant is dry? What does this increase? What happens to the transpiration rate if its windy? why

What is a photometer? What does it measure? What is it assumed that the water uptake is directly related to? what can you use it to estimate? Why  cut a shoot underwater? Why cut it at a slant? What do you have to check their isn’t any of? Why insert the shoot into the apparatus underwater? When removing the photometer what do you check? After drying the leaves what do you allow time for? What do you have to keep constant? Example? What do you need to record? What do you time the distance moved? 

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Is the evaporation of water from a plant surface, the leaves, gas exchange, stomata to let in carbon dioxide so it can produce glucose, photosynthesis, lets water out, Inside the leaf than in the air, so water moves out of the lead down he water potential gradient when the stomata open, its really a side effect of the gas exchange needed for photosynthesis, 

The water potential gradient, light, its faster because the stomata open when it gets light and close when its dark so theres little transpiration, the fast the transpiration rate because warmer water molecules have more energy sot hey evaporate from the cells inside the leaf faster this increases the water potential gradient between the inside and outside of the leaf making water diffuse out of the leaf faster, the lower the humidity the faster the transpiration rate, the water potential gradient between the leaf and the air is increased which increases the transpiration, the windier it is the faster the transpiration rate because lots of air movement blows away water molecules from around the stomata which increases the water potential gradient which increases the rate of transpiration

Is a piece of equipment used to estimate transpiration rates, water uptake by a plant, water loss by the leaves, to estimate how different factors affect the transpiration rate, to prevent air from entering the xylem, to increase the surface area available for water uptake, is full of water with no air bubbles, so no air can enter, make sure its airtight and watertight, acclimatise and then shut the tap, conditions constant like temp and air humidity, the starting position of the air bubble, distance moved by the bubble per unit time 

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Name three xerophytes? What are they adapted for? What do their adaption prevent? By? Where are xerophytes stomata? Why?  What do they have a layer of? What does this do? Reducing what? What do their curled leaves do? What does it lower? And protects what? What does it have instead of leaves? What does this do? What does the thick waxy layer do? Why? What does the reduced number of stomata do?

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Cacti, pine trees and prickly pears, to live in dry climates, from losing too much water by transpiration, stomata are sunk in pits so theyre sheltered from the wind which helps to slow transpiration down, a layer of hair which traps moist air around the stomata and reduces the water potential gradient between the leaf and air slowing transpiration, curled leaves traps moist air slowing down transpiration it also lowers the exposed surface area for losing water and protects the stomata from wind, spines instead of leaves to reduces surface area for water loss, thick waxy layer on epidermis which reduces water loss by evaporation because the layer is waterproof meaning water cant move through it, a reduced number of stomata means there are fewer places water can be lost

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What is translocation the movement of? Examples? What are dissolved substances sometimes called? What does it require? What does it happen in? What does translocation move substances from and then to? Whats the source of a substance? What sort of concentration? Whats sink? What sort of concentration? Example: Whats the source of sucrose? Why? Wheres the sink? Especially where? Why? What do enzymes maintain? How? Give example? What does this assure? Example: In potatoes what is sucrose converted to? in what areas? So where is their always a lower concentration of sucrose? What does this assure?

What aren’t scientists certain of? What’s the best supported theory? What is active transport used to do? of the what? at the what? example of solutes and source? What does this lower? Inside what? so what does water do? Via what? what does this create? In what? at the what? of the what? What happens to solutes at the sink end? What does this increase? In the what? so what does water also leave? What does this lower? In the what? What’s the result? What does this gradient push?   

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Is the movement of dissolved substances to where they’re needed in a plant, for example sugars like sucrose and amino acids, assimilates, it requires energy and happens in the phloem, from sources to sinks, of a substance is where its made so its at a high concentration there and the sink is the area where its used up so its at a lower concentration there, is the leaves where its made and the sink are the other parts of the plant especially the food storage organs and the meristems in the roots stems and leaves as they are the areas of growth, a concentration gradient from the source to the sink by changing the dissolved substances at the sink by breaking them down or making them into something else, it makes sure there’s always a lower concentration at the sink than at the source, into starch in the sink areas so theirs always a lower concentration of sucrose at the sink than inside the phloem this makes sure a constant supply of new sucrose reaches the sink from the phloem

Exactly how the dissolved substances are transported from source to sink by translocation, mass flow hypothesis, actively load the dissolved solutes into the sieve tunes of the phloem at the source, sucrose for photosynthesis and the leaves, lowers water potential inside the sieve tubes so water enters the tubes by osmosis, creates high pressure inside the sieve tubes at the source end of the phloem, solutes are removed from the phloem to be used up, increases the water potential inside the sieve tubes so it also leaves by osmosis, this lowers the pressure inside the sieve tubes, a pressure gradient from the source end to the sink end, it pushes solutes along the sieve tubes to where they’re needed

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If you remove a ring of bark from a woody stem what does it contain? What doesn’t it contain? What forms above the ring? What do you find if you analyse the fluid from the bukge? What is this evidence of? What can you use to investigate pressure in phloem? How? Where does sap flow out quicker? What’s this evidence of? What does a metabolic inhibitor stop? What happens if you put it in phloem? What’s this evidence of? Is the experimental model for mass flow supportive or not?   

Where does sugar travel? Is this supportive or against? What would sieve plates do to mass flow? What would be needed? 

In an experiment of mass flow hypothesis containers are lined with selectively permeable membrane like what? what does the top tube represent? And the bottom tube? What does the first container represent? What does it contain? And the second container represents what? and contains? Water enters the first container by what proves? What does this increase? What dos this cause? Where does pressure increase? Forcing what where?  

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Phloem not xylem, a bulge, you’ll find a higher concentration of sugars than the fluid from below the ring, that there’s a downward flow of sugars, aphids by piercing the phloem then their bodies are removed leaving mouthparts behind which allows the sap to flow out, quicker near the leaves than down the stem there’s a pressure gradient, it stops ATP production, then translocation stops this is evidence of active transport, supportive

To many different sinks not just to the one with the highest water potential like the model suggests, create a barrier to mass flow, a lot of pressure would be needed for the solutes to get through at a reasonable rate

Just like cells, phloem and xylem, the source which contains a concentrated sugar soloution, the sink and contains a weak sugar soloution, by osmosis which increases the pressure which causes the sugar soloution to flow along the top tube i.e. phloem, pressure increases in B forcing water out and back through the bottom tube i.e xylem 

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