• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The transport system in plants moves water soluble molecules by vascular tissue. There are two types of vascular tissue which are Xylem and Phloem.

Extracts from this document...

Introduction

Xylem and Phloem The transport system in plants moves water soluble molecules by vascular tissue. There are two types of vascular tissue which are Xylem and Phloem. Both of them are specialised to carry out their role in the plant and they are normally found together in vascular bundles throughout the plant. The xylem tissue transports water and soluble minerals up the plant towards the leaves for photosynthesis whereas the phloem tissue transports the sugars made by the reaction up and down the plant to places where it is needed. Both of the tissues are highly specialised and they have other tissues accompanying them in the vascular bundles to give strength. ...read more.

Middle

Xylem The xylems are many endless vessels starting from the roots and going to all the area of a plant. The walls of the vessel are made up of dead cells strengthened by lignin forming an endless tube. The lignin is water proof and strengthens the vessels and internal structure which prevents the vessels collapsing when there is a low pressure potential of water inside which maybe in summer time when less water is available. The lignin forms patterns in the wall which also allow the vessels to be flexible and stretch to accommodate water however in some places the lignin is slightly not complete to leave pits. ...read more.

Conclusion

The sieve tube cells are not true cells as they do not have a nucleus or cytoplasm as this enables them to carry out their role. The sugar is dissolved in water to form sap as the phloem has to transport water based substances. At the end of each cell in the phloem vessel there are sieve walls which allow the sap to flow through the vessel. In between the sieve tubes are true companion cells and their role is to produce ATP energy which is used to load sucrose into the sieve tubes therefore the companion cells contain many mitochondria. The companion cells and sieve tubes have small gaps between them which allow minerals and substances to flow via the apoplastic pathway. ?? ?? ?? ?? Bilaal Hussain ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Exchange, Transport & Reproduction section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

3 star(s)

***
This is a summary of the roles of xylem and phloem. It is too short to explain ideas fully, some relevant biology is missing altogether, and in places scientific language has not been used carefully.

Marked by teacher Adam Roberts 20/08/2013

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Describe the molecular structure of starch (amylase), glycogen and cellulose, and relate these structures ...

    4 star(s)

    It is the chief constituent of cell walls in living organisms. Wood is mostly cellulose, making cellulose the most abundant type of organic compound on the Earth. Cellulose molecules tend to be straight chains, and the fibers which result from collections of cellulose molecules have the strength to form the supporting structures of plants.

  2. Marked by a teacher

    Investigating how sugars are metabolised by yeast

    4 star(s)

    and Fructose being classified as a ketone (compound containing carbonyl groups with two hydrocarbon groups attached to it). The following diagram shows this clearly: To conclude, Fructose is metabolized more productively by yeast than Glucose, Sucrose, Maltose and Lactose. It may be because it's easier to break down a ketonic structure i.e Fructose than an aldehyde structure i.e Glucose.

  1. Osmosis in Living Tissue.

    -3.3 10.0 3.3 -1.7 -6.7 -5.6 -10.0 10.1 3.3 -0.9 -10.0 -6.6 -13.3 4.8 3.2 -3.3 0.0 -9.8

  2. Effects of exercise on cardiovascular system

    - to measure the heart rate the number of pulses is counted over 15 seconds and this number is multiplied by 4 to get a heart rate per minute. This is repeated three times and outcomes are recorded. 2. subject carries on exercise on the stepper for the duration of

  1. Osmosis in Potato cells

    * A scalpel was used to cut the potato chips from the potato. * Five test tubes were used to contain the solutions and one potato chip each. * A test tube rack was used to hold the test tubes in place.

  2. Investigating osmosis on swede cells.

    factors that speed up or slow down the movement of these particles will affect the rate of osmosis. I will be able to calculate the water potential by finding where the line of percentage change for mass and length crosses the axis.

  1. Plan and carry out an experiment to investigate Osmosis in Potato tissue

    This graph above shows a clear indication that there was an overall decrease in mass during the experiment. Evaluating The experiment was very successful in my opinion. I obtained a large quantity of very accurate results from which I was able to create informative graphs.

  2. Investigation into reducing sugar content of a variety of soft drinks (not diet).

    in each test to produce an accurate calibration curve. * The quantities of Benedict's reagent and soft drink should be the same as the calibration values. * The temperature and length of time, which the solutions are heated, should be kept constant to prevent any further colour change and inaccuracies.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work