6 th Year Biology Higher Level Wesley Hammond Structure and Transport of a Flowering Plant No part of this publication may be copied, reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from The Dublin School of Grinds. Ref: 6/bio/h/wh/ StructureandTransportFloweringPlants
38
Embed
Structure and Transport of a Flowering Plant...Structure and Transport of a Flowering Plant No part of this publication may be copied, reproduced or transmitted in any form or by any
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
6th YearBiology
Higher Level Wesley Hammond
Structure and Transport of a Flowering Plant
No part of this publication may be copied, reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from The Dublin School of Grinds.
Oral Preparation CoursesSeparate to the Easter Revision Courses, The Dublin School of Grinds is also running Oral Preparation Courses. With the Oral marking component of the Leaving Certificate worth up to 40%, it is of paramount importance that students are fully prepared for these examinations. These courses will show students how to lead the Examiner towards topics that the student is prepared in. This will provide students with the confidence they need to perform at their peak.
ORAL PREPARATION COURSE FEES:
PRICE TOTAL SAVINGS
1st Oral Course €140 €140 -
2nd Oral Course €100 €240 €40
Looking to maximise your CAO points?Easter is well known as a time for students to vastly improve on the points that they received in their mock exams. To help students take advantage of this valuable time, The Dublin School of Grinds is running intensive exam-focused Easter Revision Courses. Each course runs for five days (90 minutes per day).
The focus of these courses is to maximise students’ CAO points. Special offer: Buy 1st course and get 2nd course free. To avail of this offer, early booking is required as courses were fully booked last year.
What do students get at these courses?
9 90 minutes of intensive tuition per day for five days, with Ireland’s leading teachers.
9 Comprehensive study notes.
9 A focus on simple shortcuts to raise students’ grades and exploit the critically important marking scheme.
To book, call us on 01-442 4442 or book online at www.dublinschoolofgrinds.ie
NOTE: These courses are built on the fact that there are certain predicable trends that appear and reoccur over and over again in the State Examinations.
FREE DAILY BUS SERVICE For full information on our Easter bus service, see 3 pages ahead.
NOTE: Any bookings for Junior Cert courses will also receive a weekly grind in one subject for the rest of the academic year, free of charge. This offer applies to 3rd and 2nd year students ONLY.
Timetable An extensive range of course options are available over a two-week period to cater for students’ timetable needs. Courses are held over the following weeks:
» Monday 21st March – Friday 25th March 2016 » Monday 28th March – Friday 1st April 2016
All Easter Revision Courses take place in The Talbot Hotel, Stillorgan (formerly known as The Stillorgan Park Hotel).
BOOK EARLY TO AVAIL OF THE SPECIAL OFFER
BUY 1ST COURSE GET 2ND COURSE
F R E E ! Due to large course content, these subjects have been
divided into two courses. For a full list of topics covered in these courses, please see 3 pages ahead.
*
6th Year Easter Revision CoursesSUBJECT LEVEL DATES TIME
Accounting H Monday 21st March – Friday 25th March 8:00am - 9:30am
Agricultural Science H Monday 28th March – Friday 1st April 2:00pm - 3:30pm
Applied Maths H Monday 28th March – Friday 1st April 8:00am - 9:30am
Art History H Monday 28th March – Friday 1 April 8:00am - 9:30am
Biology Course A* H Monday 21st March – Friday 25th March 8:00am - 9:30am
Biology Course A* H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
Biology Course A* H Monday 28th March – Friday 1st April 10:00am - 11:30am
Biology Course B* H Monday 21st March – Friday 25th March 10:00am - 11:30am
Biology Course B* H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
Biology Course B* H Monday 28th March – Friday 1st April 8:00am - 9:30am
Business H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
Business H Monday 28th March – Friday 1st April 8:00am - 9:30am
Chemistry Course A* H Monday 28th March – Friday 1st April 12:00pm - 1:30pm
Chemistry Course B* H Monday 28th March – Friday 1st April 2:00pm - 3:30pm
Classical Studies H Monday 21st March – Friday 25th March 8:00am - 9:30am
Economics H Monday 21st March – Friday 25th March 8:00am - 9:30am
Economics H Monday 28th March – Friday 1st April 10:00am - 11:30am
English Paper 1* H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
English Paper 2* H Monday 21st March – Friday 25th March 10:00am - 11:30am
English Paper 2* H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
English Paper 2* H Monday 28th March – Friday 1st April 10:00am - 11:30am
English Paper 2* H Monday 28th March – Friday 1st April 12:00pm - 1:30pm
French H Monday 21st March – Friday 25th March 10:00am - 11:30am
French H Monday 28th March – Friday 1st April 8:00am - 9:30am
Geography H Monday 28th March – Friday 1st April 8:00am - 9:30am
Geography H Monday 28th March – Friday 1st April 10:00am - 11:30am
German H Monday 21st March – Friday 25th March 10:00am - 11:30am
History (Europe)* H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
History (Ireland)* H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
Home Economics H Monday 21st March – Friday 25th March 10:00am - 11:30am
Irish H Monday 21st March – Friday 25th March 10:00am - 11:30am
Irish H Monday 28th March – Friday 1st April 12:00pm - 1:30pm
Maths Paper 1* H Monday 21st March – Friday 25th March 8:00am - 9:30am
Maths Paper 1* H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
Maths Paper 1* H Monday 28th March – Friday 1st April 10:00am - 11:30am
Maths Paper 1* H Monday 28th March – Friday 1st April 2:00pm - 3:30pm
Maths Paper 2* H Monday 21st March – Friday 25th March 10:00am - 11:30am
Maths Paper 2* H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
Maths Paper 2* H Monday 28th March – Friday 1st April 12:00pm - 1:30pm
Maths Paper 2* H Monday 28th March – Friday 1st April 4:00pm - 5:30pm
Maths O Monday 21st March – Friday 25th March 8:00am - 9:30am
Maths O Monday 28th March – Friday 1st April 12:00pm - 1:30pm
Physics H Monday 28th March – Friday 1st April 10:00am - 11:30am
Spanish H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
Spanish H Monday 28th March – Friday 1st April 10:00am - 11:30am
6th Year Oral Preparation CoursesSUBJECT LEVEL DATES TIME
French H Sunday 20th March 10:00am - 2:00pm
German H Saturday 26th March 10:00am - 2:00pm
Irish H Saturday 26th March 10:00am - 2:00pm
Spanish H Saturday 19th March 1:00pm - 5:00pm
5th Year Easter Revision CoursesSUBJECT LEVEL DATES TIME
Maths H Monday 28th March – Friday 1st April 8:00am - 9:30am
English H Monday 28th March – Friday 1st April 4:00pm - 5:30pm
Note: 5th year students are welcome to attend any 6th year course as part of our buy 1 get 1 free offer.
3rd Year Easter Revision CoursesSUBJECT LEVEL DATES TIME
Business Studies H Monday 28th March – Friday 1st April 8:00am - 9:30am
English H Monday 21st March – Friday 25th March 8:00am - 9:30am
English H Monday 28th March – Friday 1st April 2:00pm - 3:30pm
French H Monday 28th March – Friday 1st April 12:00pm - 1:30pm
Geography H Monday 28th March – Friday 1st April 12:00pm - 1:30pm
German H Monday 21st March – Friday 25th March 8:00am - 9:30am
History H Monday 21st March – Friday 25th March 4:00pm - 5:30pm
Irish H Monday 28th March – Friday 1st April 2:00pm - 3:30pm
Maths H Monday 21st March – Friday 25th March 10:00am - 11:30am
Maths H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
Maths H Monday 28th March – Friday 1st April 10:00am - 11:30am
Maths O Monday 28th March – Friday 1st April 12:00pm - 1:30pm
Science H Monday 28th March – Friday 1st April 2:00pm - 3:30pm
Science H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
Spanish H Monday 21st March – Friday 25th March 12:00pm - 1:30pm
2nd Year Easter Revision CoursesSUBJECT LEVEL DATES TIME
Maths H Monday 21st March – Friday 25th March 2:00pm - 3:30pm
NOTE: Any bookings for Junior Cert courses will also receive a weekly grind in one subject for the rest of the academic year, free of charge. This offer applies to 3rd and 2nd year students ONLY.
Contents
Structure of a Flowering Plant:
Structure of a Flowering Plant …………………………………………………………………….…3
(C) The Dublin School of Grinds Page 21 Wesley Hammond
Transport in a
Flowering Plants
(C) The Dublin School of Grinds Page 22 Wesley Hammond
Why plants need transport?
Plants need to be able to transport water, carbon dioxide, oxygen andminerals.
How do roots of plants take in water from the soil?
Root hairs absorb water by osmosis.
NOTE: Osmosis is the movement of water across a semi permeable membrane from a region of high water concentration (in the soil) to a low water concentration (in the root).
How are root hairs adapted for water absorption?
• Root hairs have thin walls (helps them to absorb water).
• Root hairs occur in large numbers (large surface area).
(C) The Dublin School of Grinds Page 23 Wesley Hammond
Movement of water into xylem:
• Water diffuses from the root hair into the ground tissue.
• It then diffuses from ground tissue into the xylem in centre of root.
How do the roots of plants absorb minerals?
• Plants require minerals to function (calcium, magnesium)
• Minerals are absorbed from the soil by root hairs in a process calledactive transport (requires energy)
• Root hairs have lots of mitochondria to supply energy.
How does water move up through a plant in the xylem?
Water moves up through a plant in two different ways:
1) Root pressure
2) Transpiration
Root pressure
Water taken in by the roots by osmosis causes a build up of waterpressure.
This root pressure pushes water up through the xylem
Note: Does not fully explain how water travels up large trees
(C) The Dublin School of Grinds Page 24 Wesley Hammond
Transpiration:
Transpiration is the loss of water vapour from the leaves of the plant.
Transpiration occurs through the stomata of a leaf (openings on the underside of a leaf).
How the Cohesion Tension model helps explain transpiration and the upward movement of water:
Cohesion Tension model • Allows large amounts of water to move quickly from roots to leaves in
warm conditions.
• Can move 220 litres in one hour up through a plant.
• This model was put forward by Henry Dixon and John Joly (IrishScientist in Trinity College).
• Cohesion: the sticking of water molecules to each other.
• Adhesion: when different molecules stick together (water sticks to the wall of the xylem)
Steps involved in the Cohesion Tension model:
1) Water evaporates from the xylem out through the stomata into the air(transpiration).
2) During transpiration each water molecule is pulled through the xylem.
3) Due to cohesion the next water molecule is pulled along by the one infront of it.
4) Xylem are adapted for movement of water because they are narrow.
(C) The Dublin School of Grinds Page 25 Wesley Hammond
5) When the water column in the xylem is stretched it is said to be undertension.
How is xylem adapted for transporting water?
It is narrow. It has lignin. Has pits.
Control of transpiration in leaves 1) Leaves have cuticle which does not allow water to pass through (cuticle
thicker on upper surface as this side is exposed to the sun)
2) Stomata are located on lower surface of leaf to reduce water loss (moreevaporation would occur on upper surface).
(C) The Dublin School of Grinds Page 26 Wesley Hammond
3) Each stomata is surrounded by two guard cells. The stomata can open orclose by the guard cells changing shape.
NOTE: Stomata are normally open during the day to allow gas exchange for photosynthesis. They close at night to reduce water loss.
The following environmental factors affect stomata opening or closing:
1) Plants lose too much water2) High temperatures3) High wind4) Carbon dioxide concentration
NOTE: Plants do not grow well in dry conditions because the stomata will remain closed for long periods.
How does CO2 concentration control stomata opening or closing?
High concentration of CO2:
• High levels of CO2 cause stomata to close.
• Photosynthesis rate decreases in the evening causing the build-up of CO2.
Low concentration of CO2:
• Low levels of CO2 cause the stomata to open.
• When photosynthesis begins in the morning CO2 is absorbed by themesophyll cells (ground tissue).
(C) The Dublin School of Grinds Page 27 Wesley Hammond
SUMMARY: High concentration of CO2 Stomata close
Low concentration of CO2 Stomata open
How do stomata open or close?
• Guard cells open and close the stoma by changing shape.
• When water enters the guard cell by osmosis, they swell and becometurgid.
• This causes the guard cells to buckle outwards creating a gap betweenthe guard cells.
• When the guard cells lose water they shrink, which causes the stoma toclose.
Gas exchange in a leaf:
Carbon dioxide:
Stomata helps with gas exchange. Large number of stomata increases theamount of gas exchange.
Carbon dioxide diffuses into the mesophyll of the leaf (ground tissuewhere photosynthesis takes place)
Oxygen:
Oxygen diffuses from the mesophyll of leaf into the air spaces and out ofthe stomata.
Water vapour:
Water vapour also diffuses out of the leaf through the stomata(transpiration)
(C) The Dublin School of Grinds Page 28 Wesley Hammond
Gas exchange in stems:
Lenticels are opening in the stem that allow gas exchange.
Normally oxygen diffuses inwards through a lenticels (needed forrespiration) and carbon dioxide diffuses outwards.
Food storage organs in plants:
Modified roots:
• Dicot plants can have large tap roots to store food (starch).
• This food is used to produce flowers, seeds and fruits.
Example: Carrots, Turnips
Modified stem:
• Potato plants produce an underground stem to store food (starch).
• These swollen stems are called tubers.
Modified leaves:
Onions, daffodils and tulips all produce a bulb.
What is a bulb?
• A bulb is an underground stem that has swollen fleshy leaves to storefood.
• The bulb is protected by a dry scaly leaf on the outside.
(C) The Dublin School of Grinds Page 29 Wesley Hammond
Exam Paper 2004, Question 4:
(C) The Dublin School of Grinds Page 30 Wesley Hammond