Class notes
Biology-notes-for-O-level
- Course
- Institution
- Book
Biology-notes-for-O-level
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
Biochemistry-Cell Signaling Pathways Growth Factors
-
TEST BANK FOR CELL BIOLOGY, 3RD EDITION, THOMAS POLLARD, WILLIAM EARNSHAW, JENNIFER LIPPINCOTT-SCHWARTZ, GRAHAM JOHNSON
-
Class notes Mdcat Biology
Seller
Follow
BrainEdge
Reviews received
Content preview
1. Cells structure and Organisation1.1 Plant Cells and Animal Cells:
Fig.1.0 Basic structures of an animal cell and a plant cell.
1. Cell wall:
• Porous.
• Permeable.
• Non-living structure made of cellulose.
2. Cell membrane/Plasma membrane
• Semi-permeable/Partially permeable(Only certain parts can pass through it and some aren't able).
3. Cytoplasm
• Contains cell organelles.
• Food substances.
• Mostly H2O.
4. Vacuole/Sap vacuole/Large central vacuole
• Mostly H2O.
5. Nucleus
• Controls all activities of a cell.
6. Chloroplasts
• Contains green pigment called Chlorophyll which is important for doing Photosynthesis.
7.Differences between plant cells and animal cells
•Only plant cells have cell wall.
•Only plant cells have chloroplasts.
•Plant cells have a large central vacuole while some animal cells have small vacuoles and some doesn't
have any.
• Plant cells have a regular shape while animal cells have irregular shape.
Biology Page 1
, 1.2 Specialized/Modified cells:
1. Root Hair Cell:
• To absorb water and minerals.
• Finger-like projection:
Increases surface area for absorption.
Has a larger vacuole to store more H2O.
Fig.1.2 Root hair cell.
2. Red blood cell:
• To carry/transport oxygen.
• Packed with haemoglobin (red pigment).
• No nucleus.
• Biconcave shape.
Fig.1.3 Red blood cells.
3. Xylem vessels:
• To transport H2O and minerals.
• Supporting plant body.
Fig.1.4(a)Whole plant, (b) plant stem and (c)xylem vessel
Biology Page 2
,2. Diffusion and Osmosis
Monday, October 20, 2008
8:15 PM
2.1 Diffusion
1. Diffusion:
• The movement of particles form an area of higher concentration to another
area of lower concentration down a concentration gradient.
Fig. 2.1 Representation of diffusion.
2.2 Osmosis
2. Osmosis:
• The movement of water molecules from an area of high concentration to an
area of lower concentration through a semi-permeable membrane.
Fig. 2.2 (a)The sugar solution in the bag is more concentrated than the water
outside the bag. (b)The water in the bag is more dilute than the sugar solution
outside the bag. (c)The sugar solution in the bag is of the same concentration
as that of the solution outside the bag.
Biology Page 3
, 2.3 Cells and Osmosis:
Fig. 2.3 The behaviour of cells in solutions of different concentrations.
2.4 Active Transport:
3. Active Transport:
• The movement of particle from an area of lower concentration to an area of
higher concentration by using energy.
4. Active transport is involved in a number of processes occurring within an
organism. This includes the absorption of:
• Dissolved mineral salts by the root hairs,
• Glucose and amino acids by cells in the small intestine of humans.
Biology Page 4
The benefits of buying summaries with Stuvia:
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
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
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 BrainEdge. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53068 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now