Friday, 23 October 2015

Fungi (moulds, mushrooms, yeasts)

Fungi (moulds, mushrooms, yeasts)
These are eukaryotes (with a membrane-bound nucleus).  Their cells contain organelles including mitochondria.  Their cell wall is made of chitin and glycans.  Most fungi grow as, and obtain their nutrition through their hyphae.  They can be grouped according to their fruiting bodies.  Uniquely, yeasts reproduce by budding.  Examples:  Candida albicans and Saccharomyces cerevisiae.
Mushroom Structure
Yeast Cell Structure

Classifying Things - Viruses

Things that are classified by biologists

Viruses (are not living organisms!)
Viruses are grouped according to the genetic (replicating) material they contain (deoxyribosenucleic acid or ribosenucleic acid) and they can have a protein coat surrounding that.  Others can have a lipid layer surrounding the protein coat.  Examples: - Tobacco Mosaic Virus and Chickenpox.

Generalised Virus Structure

They can come in many shapes from simple spheres to the more complex coliphage.


Getting there & Dichotomous Keys

A new title -
Biology 
Life, Studied.

A Study & Revision Guide
IGCSE & beyond
through AS to IB Diploma and A-Level

to University entrance.

Contents
Page
4 Introduction
5 Measurements used in Biology
6 How to use the guide 
7 Unit 1 – Classification and Variety of Organisms
25 Unit 2 – Plant and Animal Cells
60 Unit 3 – Nutrition in Plants
73 Unit 4 – Support in Plants and Animals 
91 Unit 5 – Gaseous Exchange in Animals
105 Unit 6 – Transport Systems in Plants and Animals
132 Unit 7 – Respiration 
148 Unit 8 – Diet, Biochemicals & Digestion 
187 Unit 9 – Control Systems – Homeostasis, Nerves and Hormones
240 Unit 10 – Inheritance & the Genetic Code
263 Unit 11 – Variation Plant and  Human Reproduction
303 Unit 12 – Genetics, Selection and Evolution 
347 Unit 13 – Ecology and Environment
410 Unit 14 – Graphing and Data Presentation
416 Unit 15 – Microbiology and Biotechnology 
447 Unit 16 – Human Health & Disease
461 Unit 17 – Safety Symbols


Currently, it is all written down and editing is occurring.  It will proceed to the publishers in Kuwait for hard copy production.  Before that it will go to Kindle.

Anyway, as a taster here are some sections from Unit 1........

To avoid confusion around the world and even within a country, the Swedish scientist Karl Linne (Carol Linnaeus), came up with binomial nomenclature (using two names) in Latin for the naming of organisms.  The two parts of the name include the genus and species names.  They are written in italics if we are using a word processing system.  If we are writing by hand, then we underline the names using a ruler.

The Eurasian Red Squirrel is named as Scuirus vulgaris under this system.  As you would guess, the local names just within Europe will be many, but all references should include the Latin name so no confusion occurs when talking about particular organisms between biologists around the world.

At family and genus level organisms can look very similar and we have to be able to tell them apart.  Keys (dichotomous ones) can be prepared by those who know the organisms well to help those who are unfamiliar with them, be able to identify them.
We need to be able to read and prepare dichotomous keys.

Here are four beetles:
Key

1. Does the beetle have a long narrow abdomen (body)?
If yes  ------------------------------------------- Cockroach.
If no --------------------------------------------- Go to question 2.

2. Does the beetle have any spots on its’ wing cases (elytra)?
If yes ------------------------------------------- Go to question 3.
If no -------------------------------------------- Staghorn beetle.

3. Does the beetle have more than one spot on each elytra?
If yes --------------------------------------------- 6 Spot Ladybird.
If no ---------------------------------------------- 2 Spot Ladybird.

This might appear simple, but this example has been made obvious to demonstrate the idea.

This skill will be useful when we are presented with keys in examination situations or have to use one when doing other studies (looking at species diversity in ecology, for example).



Wednesday, 9 October 2013

Biology Revision Guide - In a nutshell

Fed up of dealing with other folk's revision guides for Biology (and the other sciences) at GCSE, IGCSE, AS, A-Level and International Baccalaureate Diploma with their errors and "not quite hitting the core of the syllabus (curriculum)", I have decided to write up a guide that starts with the basics of I-GCSE and moves into the common topics of AS, A-Level and IB such that a specialist book for each one becomes unnecessary.

One guide will take you all the way through from preparation for Cambridge University (CIE) CheckPoint exams through to University.

For example, a topic dealt with only at I-GCSE will be looked at at that level of difficulty, one that is covered at I-GCSE, and also at IB Standard Level and then IB Higher level would get looked at in increasing levels of difficulty and practice questions will be included for each level (answers at the back of the book).

I will draw all the diagrams myself and take the existing past paper questions, look at the questions that regularly occur on the papers for topics and use those (re-modelled) as practice standards.

Not wanting the book to be too big either - paperback size should be the aim - I aim for it to fit easily in a jacket pocket for reading in a car or on a  school bus.  Also, given the international nature of the educational syllabi covered, one should assume that internet connectivity is not always possible or reliable and that a physical book may well be the best way to store reference information for many students.
The chapters are already outlined and the first few are completed.  However, I may be some time......