Biology - 9201 OxfordAQA

Exchange And Transport In Plants

Akopọ

A tall forest tree lifts hundreds of litres of water from the soil to its highest leaves every hot day, and it does it with no heart, no muscle and no moving part of any kind. The whole system is powered by water evaporating from the inside of a leaf. Once you can see how that works, a plant stops looking like a passive green thing in the ground and starts looking like the most efficient piece of plumbing in biology.

This lesson follows two journeys. The first is a gas: carbon dioxide drifting in through a pore only a few thousandths of a millimetre wide, reaching a cell that will build it into sugar. The second is water, pulled from between soil particles, through a root hair, up a column of dead hollow cells and out into the air. Along the way you will meet the guard cells that decide how far the pore opens, the two transport tissues that carry very different cargo in different directions, and the reason a plant left on a windowsill in August goes limp by the afternoon.

Awọn Afojusun

  1. In flowering plants: carbon dioxide enters leaves by diffusion through the stomata; most of the water and mineral ions are absorbed by roots.
  2. The surface area of roots is increased by root hairs, and the surface area to volume ratio of leaves is increased by the flattened shape and internal air spaces.
  3. Plants have stomata to obtain carbon dioxide from the atmosphere and to remove oxygen produced in photosynthesis. Stomata also help to control the rate of water loss.
  4. Plants mainly lose water vapour from their leaves. Most of the loss of water vapour takes place through the stomata.; Evaporation is more rapid in hot, dry and windy conditions.; If plants lose water faster than it is replaced by the roots, the stomata can close to prevent wilting.
  5. The size of stomata is controlled by guard cells, which surround them.
  6. Flowering plants have separate transport systems: xylem tissue transports water and mineral ions from the roots to the stem and leaves; the movement of water from the roots through the xylem and out of the leaves is called the transpiration stream; phloem tissue carries dissolved sugars from the leaves to the rest of the plant, including the growing regions and the storage organs. This process is called translocation; the structure of the xylem and the phloem is related to its function.

Àwòrán ọpọlọ

A ti ṣe àwòrán kókó yìí kí o lè rí bí àwọn èrò ṣe so pọ̀.

Ṣí àwòrán ọpọlọ nínú áàpù

Akọ̀wé Ẹ̀kọ́

A leaf has a problem it cannot solve cleanly. To photosynthesise it must let carbon dioxide in from the air, so its surface has to be open. But an open surface also lets water escape, and the inside of a leaf is wet. Every pore that admits the gas the plant needs also loses the water the plant cannot easily replace. Almost everything in this topic, from the shape of a leaf to the behaviour of a pair of guard cells at noon, is a compromise between those two pressures.

Àkọsílẹ̀ Ẹ̀kọ́ Pípé wà lórí Ohun Èlò Green Bridge

Gba ohun èlò Green Bridge CBT sórí fóònù tàbí kọ̀mpútà rẹ fún gbogbo ilé ìkàwé IGCSE: ìwé ìdánwò àtijọ́, ìlànà ìdíwọ̀n, àwòrán èrò, káàdì ìkẹ́kọ̀ọ́ àti ẹ̀kọ́ ohùn.

Awọn akọsilẹ ẹkọ ni kikun pẹlu awọn aworan apejuwe
Oluranlọwọ ẹkọ ti AI ṣe agbara rẹ
Ìdánwò àdáṣe onítọ̀kọ̀ tí a ń ṣàyẹ̀wò lẹ́sẹ̀kẹsẹ̀ tí o bá parí
O wa lori Android, Windows, macOS, ati Linux Áàpù iOS ń bọ̀ láìpẹ́

Ìdánwò Ẹ̀kọ́

Oriire fun ipari ẹkọ lori Exchange And Transport In Plants. Ni bayi ti o ti ṣawari naa awọn imọran bọtini ati awọn imọran, o to akoko lati fi imọ rẹ si idanwo. Ẹka yii nfunni ni ọpọlọpọ awọn adaṣe awọn ibeere ti a ṣe lati fun oye rẹ lokun ati ṣe iranlọwọ fun ọ lati ṣe iwọn oye ohun elo naa.

Iwọ yoo pade adalu awọn iru ibeere, pẹlu awọn ibeere olumulo pupọ, awọn ibeere idahun kukuru, ati awọn ibeere iwe kikọ. Gbogbo ibeere kọọkan ni a ṣe pẹlu iṣaro lati ṣe ayẹwo awọn ẹya oriṣiriṣi ti imọ rẹ ati awọn ogbon ironu pataki.

Lo ise abala yii gege bi anfaani lati mu oye re lori koko-ọrọ naa lagbara ati lati ṣe idanimọ eyikeyi agbegbe ti o le nilo afikun ikẹkọ. Maṣe jẹ ki awọn italaya eyikeyi ti o ba pade da ọ lójú; dipo, wo wọn gẹgẹ bi awọn anfaani fun idagbasoke ati ilọsiwaju.

  1. Through which structures does carbon dioxide mainly enter a leaf? A. The stomata B. The xylem vessels C. The root hairs D. The waxy cuticle Answer: A
  2. Which statement about xylem vessels is correct? A. They are living cells with sieve plates B. They carry sucrose from the leaves to the roots C. They are dead, hollow tubes with lignified walls D. They transport water downwards from the leaves to the roots Answer: C
  3. How are mineral ions taken up by root hair cells from the soil? A. By osmosis B. By active transport C. By transpiration D. By translocation Answer: B
  4. Which set of conditions gives the highest rate of transpiration? A. Cool, still, humid B. Warm, still, humid C. Cool, windy, dry D. Warm, windy, dry Answer: D
  5. A stoma opens when: A. Water leaves the guard cells by osmosis and they straighten B. Water enters the guard cells by osmosis and they curve apart C. The guard cells lose their chloroplasts D. The thick outer wall of each guard cell stretches less than the inner wall Answer: B

Ṣiṣẹ́ lórí àwọn ìbéèrè wọ̀nyí nínú ohun èlò náà

Ṣiṣẹ́ lórí àwọn ìbéèrè wọ̀nyí nínú ohun èlò náà

Ṣe Adaṣe Awọn Ibeere Idanwo Adaṣe

Ṣe o fẹ ṣe adaṣe awọn ibeere idanwo adaṣe nipa Exchange And Transport In Plants? Ṣe igbasilẹ ohun elo Green Bridge CBT lati wọle si awọn ibeere idanwo adaṣe ati awọn ayẹwo adaṣe kikun fun koko-ọrọ yii.

Ṣe igbasilẹ ohun elo naa lori Google Playstore

Gbogbo ohun ti o nilo lati ṣe dara julọ ninu JAMB, WAEC ati NECO.

Green Bridge CBT Mobile App
Asiko ẹkọ AI ti ara ẹni Chat Assistant
Ìbéèrè ìdánwò IGCSE, JAMB, WAEC ati NECO tó ju 200,000 lọ
Fiwọn 1200 Awọn akọsilẹ Ẹkọ ju.
Atilẹyin Aisinipo - Kọ ẹkọ Nigbakugba, Nibi gbogbo
Tẹ̀dí Green Bridge
Àkójọpọ̀ Ìtàn Lítíréṣọ̀ & Ìbéèrè Tó Lè Dáyéé ṣẹ́lẹ̀
Tẹle iṣẹ ṣiṣe rẹ ati ilọsiwaju rẹ.
Àlàyé tí ó jinlẹ̀ fún ìmòye tó jinlẹ̀.