100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
Cells and Organisms Carry Out Exchanges with their External Environment in order to Maintain their Internal Environment £8.49
Add to cart
Quickly navigate to
Preview
  2.  
  3. AQA
  4.  
  5. A Level Biology
  6.  
  7. Unit 6 - Organisms respond to changes in their internal and external environments

Essay

Cells and Organisms Carry Out Exchanges with their External Environment in order to Maintain their Internal Environment
 5 purchases
  • Institution
  • AQA

Cells and Organisms Carro Out Exchanges with their External Environment in order to Maintain their Internal Environment full essay. Word count 1048, mark = 17/25

Preview 1 out of 2  pages

Document information

  • June 17, 2021
  • 2
  • 2019/2020
  • Essay
  • Unknown
  • B

Subjects

Written for

All documents for this subject (144)

Seller

avatar-seller
mc2001

Reviews received

Content preview

Cells and Organisms Carry Out Exchanges with their External Environment in order to Maintain
their Internal Environment.

Exchange with the external environment of cells and organisms is very important for the
maintenance of their internal environment. Exchange can take the form of diffusion, osmosis, or
active transport, and is used by cells and organisms to maintain their internal environment in
many ways. These include gas exchange, transport of water in a plant, tissue fluid and its
formation, negative feedback, and the nerve impulse.

Gas exchange is a major way cells and organisms maintain their internal environment. In cells,
the exchange of oxygen and carbon dioxide is carried out by diffusion to ensure that the cells
can function properly as they are able to respire. Organisms also carry out gas exchange -
breathing. In insects, gas exchange is carried out through spiracles, which open and close to
allow gas exchange and limit water loss. Plants carry out gas exchange through stomata in a
similar way. Fish exchange gases in their gills, and use the countercurrent exchange principle.
Their blood flows in the opposite direction to the water flowing through the gills. This ensures
the maximum diffusion of oxygen from the water to the blood, and also that an oxygen diffusion
gradient is maintained along the full length of the gills. This therefore maintains the internal
environment of the fish, as its cells are able to respire and function properly. In mammals, gas
exchange happens in the lungs. The alveoli in the lungs have a maintained diffusion gradient of
oxygen and carbon dioxide to ensure a constant supply of oxygen. This oxygen is transported
around the body in the blood so cells can use it for respiration in order to function properly.
Carbon dioxide is also removed from the body, so it does not stay in the body as waste.
Therefore, gas exchange maintains cells and organisms internal environments as it means that
cells have a good supply of oxygen so they can respire and function.

The transport of water in a plant is also a way of maintaining the internal environment. Water
molecules move out of the stomata on the leaves, along with gases. This is due to the water
potential gradient created as a result of the different humidities. Water vapour diffuses out of the
stomata, into the air spaces near them. This water is then replaced by osmosis of water into
mesophyll cells from neighbouring cells, which establishes a water potential gradient and pulls
water from the xylem. The hydrogen bonds between water molecules cause them to ‘stick’
together - a force called cohesion. When water is lost from the surface of the leaf by
evaporation, the continuous, unbroken column of water molecules means that more water
molecules are drawn up behind the lost water molecules. The column of water is therefore
moving up the xylem, called the transpirational pull. This water movement maintains the internal
environment as it prevents the plant from overheating, and also the water can be used by the
plant cells in processes such as photosynthesis. This keeps the plant alive as it provides the
plant with food.

Tissue fluid and its formation is important for the maintenance of the internal environment of
cells and organisms. Tissue fluid is a liquid that contains glucose, amino acids, fatty acids, ions
and oxygen. It is the immediate environment of cells, and is the means by which materials are
exchanged between blood and cells that are too far from the capillaries. It is formed by

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller mc2001. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £8.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

64302 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now

Start selling

Recently viewed by you

Summary ·

(3)

Samenvatting bedrijfseconomie; basisboek bedrijfseconomie/ bedrijfseconomie voor het besturen van organisaties blok 5 BMER

Exam (elaborations) ·

(0)

Dental Materials Clinical Applications for Dental Assistants and Dental Hygienists 3rd Edition By W. Stephan Eakle -Test Bank.

Exam (elaborations) ·

(0)

WGU C425 HEALTHCARE DELIVERY SYSTEMS, REGULATIONS, AND COMPLIANCE PRACTICE QUIZ |UPDATED&VERIFIED|100% SOLVED|GUARANTEED SUCCESS

Exam (elaborations) ·

(0)

Test Bank for Fundamentals of Nursing 10th Edition by Taylor full Chapters with NGN complete solutions| ULTIMATE GUIDE A+

Exam (elaborations) ·

(0)

HSCO 502 test 3: (Version 2) Latest 2019/20, Liberty University answers complete solutions, Attempt Score 92 Out of 100 Points.

Exam (elaborations) ·

(3)

Straighterline Introduction to Physics (lab) PHY250L Lab 2 Kinematics COMPLETE Worksheet (New Version August 2024) Scored 100%

Summary ·

(3)

Complete samenvatting van VTV (verpleegtechnische vaardigheden) voor kennistoets 2 in leerjaar 1 van hbo-v aan de HAN

Summary ·

(0)

De inleiding van de lessen en het handboek en deel 1: Contractvrijheid, contractuele gebondenheid en hun beperkingen.

Summary ·

(7)

Zeer uitgebreide samenvatting 2022 Verdiepend Strafrecht (8.5 gehaald) | Incl. samenvatting literatuur, arresten en meer
£8.49  5x  sold
  • (0)
Add to cart
Added