Download MODULE 01 Classification Cells and Cell Structure

MODULE 01
Classification Cells and Cell Structure
This module starts with an introduction. The first two points below only carry about 4% of the
marks and it is assumed that these are the sorts of things you have learnt at KS3 (pre GCSE)
Characteristics of living things
Characteristics of various groups of living things and how they differ from
each other.
Simple keys
Cell structure
Differences between plant and animal cells
Levels of organisation in living things
Movement of substances in and out of cells
Higlighted page references are from Mackean
Italic pages are from the IGCSE book
NOTE although Mackean is on the booklist it is here simply to supplement the
information in the IGCSE textbook. Mackean contains more detail and may be
useful to supplement or give additional information on a particular topic.
Characteristics of living organisms

These are listed on Ch1 pg 2 page 292 . Make a list of these in your note
book with a brief explanation of each one. We sometimes use MRS GREN as a
memory aid (M –movement R- respiration S – sensitivity or responding to the
environment G – growth R- reproduction E – excretion N – nutrition or feeding)

Note that breathing should always be referred to as GAS EXCHANGE.
• You need to learn these definitions
Movement
 as an action by an organism or part of an organism causing a change of
position or place
Respiration
 as the chemical reactions that break down nutrient molecules in living cells
to release energy
Sensitivity
 as the ability to detect or sense changes in the environment (stimuli) and
to make responses
Growth
 as a permanent increase in size and dry mass by an increase in cell number
or cell size or both
Reproduction
 as the processes that make more of the same kind of organism
Excretion
 as removal from organisms of toxic materials, the waste products of
metabolism (chemical reactions in cells including respiration) and
substances in excess of requirements
Nutrition
 as taking in of nutrients which are organic substances and mineral ions,
containing raw materials or energy for growth and tissue repair, absorbing
and assimilating them
Classification and diversity of living organisms
Concept and use of a classificatory system
• Define and describe the binomial system of naming species as a system in which the scientific name of an organism is
made up of two parts showing the genus and species

Chapter 1 Chapter 30 pg 268 explains how living things are divided up into
different groups and classified according to a system called the binomial
system, this gives each species a name (genus and species eg Vibrio cholerae).
You need to know VERY simply what are the basic characteristics of each of the
groups:- PLANTS, ANIMALS. Make a simple list of each group and their
characteristics – you could do this on a table.
• List the main features of the following vertebrates: bony fish, amphibians, reptiles, birds and mammals

You need to know the features of the main groups of vertebrates, namely
bony fish, amphibians, reptiles, birds and mammals. Page 5
• Know that there are other classification systems e.g. cladistics (based on RNA/ DNA sequencing data)

There are other more modern systems of classification based on RNA and
DNA. This tells us how closely animals are related to each other.
• List the main features used in the classification of the following groups: viruses, bacteria and fungi, and their
adaptation to the environment, as appropriate

You need to know VERY simply what are the basic characteristics of each of
the groups:- FUNGI, BACTERIA, VIRUSES. Make a simple list of each group and
their characteristics – you could do this on a table.

You need to know how they are adapted to their environment.

Make notes on each group, you could try to find pictures of one example of
each to make your notes more attractive. Describe the external features which
characterise the groups. You should also know the characteristics of the main
classes of vertebrates. You will find information for this in chapter 1 page 1-12
Adaptations of organisms to their environment (to be illustrated by
examples wherever possible)
:

You need to be able to describe the features of the following groups using
their characteristic features. Make a list and learn these features chapter 1
 Flowering plants (monocotylendons and dicotyledons)
 Arthropods (insects, crustaceans,arachnids and myriapods)
 Annelids
 Nematodes
 Molluscs
You should make notes on the adaptations of these animals to their environment chapter 1
Simple keys
• Use simple dichotomous keys based on easily identifiable features

Chapter 1 Pg 11 You should be able to identify organisms using a simple key.
Try and construct your own key using some common kitchen utensils. Use to
example in your book as a guide. Each question you choose should divide your
objects into two more or less even groups. groups.
These first points act as an introduction to Biology.
Cell structure and organisation
• State that living organisms are made of cells
Page 13-14 chapter 2 Chapter one starts off with an introduction explaining
that all living things are made up of cells. Make notes on this and the fact that
microscopes are used to look at cells.
• Identify and describe the structure of a plant cell (palisade cell) and an animal cell (liver cell), as seen under a light
microscope
• Relate the structures seen under the light microscope in the plant cell and in the animal cell to their functions
Make a large drawing of a plant and an animal cell and label
nucleus,
cytoplasm, cell membrane, cell wall (plant) chloroplast (plant), vacuole
(plant) and mitochondria. At the side of each label make a note of the
function (what it does) of each structure. You will find information about
this on pages 14-16
The two types of cell shown on page 14 are a liver (animal) cell and a palisade
cell (plant) cell
• Describe the differences in structure between typical animal and plant cells

Draw a table showing the differences between plant and animal cells Pg 16
Levels of organisation
• Define:
• tissue as a group of cells with similar structures, working together to perform a shared function
• organ as a structure made up of a group of tissues, working together to perform specific functions
• organ system as a group of organs with related functions, working together to perform body functions using examples
 You need to learn these definitions and be able to give examples
 tissue - a group of cells with similar structures, working together to perform a
shared function
 organ - a structure made up of a group of tissues, working together to
perform specific functions
 organ system - a group of organs with related functions, working together to
perform body functions using examples
Relate the structure of the following to their functions:
• ciliated cells – in respiratory tract
• root hair cells – absorption
• xylem vessels – conduction and support
• muscle cells – contraction
• red blood cells – transport

Chapter 2 pg 18 Page 7 shows how cells are organised and grouped
together to form tissues, organs and organ systems and eventually organisms.
Draw a flow diagram linking all these together with a brief description of each.
You need in particular to understand how the structure and adaptation relates
to the function of each of the following types of cells:




ciliated cells – in respiratory tract
root hair cells – absorption
xylem vessels – conduction and support
muscle cells – contraction
red blood cells – transport
Use the index in your text book and look up each of these types of cells.
Size of specimens
• Calculate magnification and size of biological specimens using millimetres as units
 You also need to learn the skill of drawing biological specimens
Chapter 1 page 7. You need to know how to calculate the magnification of
objects even if you don’t have access to a microscope. Chapter one page 8.
 You can draw a leaf for example and then measure it and your drawing and
work out the magnification of your drawing.
Movement in and out of cells
Diffusion
• Define diffusion as the net movement of molecules from a region of their higher concentration to a region of their lower
concentration down a concentration gradient, as a result of their random movement
• Describe the importance of diffusion of gases and solutes and of water as a solvent
 Chapter3Pg20
Chapter 4 page 26 is all about movement of substances in
and out of cells. Read this chapter and makes notes on diffusion, osmosis and
active transport.
 You must learn the definition of diffusion as the net movement of molecules
from a region of their higher concentration to a region of their lower
concentration down a concentration gradient, as a result of their random
movement. Page 20-22
 You must make sure you know the importance of diffusion in both gases and
liquids and also the fact that water is a very important solvent for living things
 Look at the experiments in your text book chapter 3 and also in MacKean
Chapter 4 (if you have a copy of this) and familiarise yourself with them. If
you can get hold of the things needed then have a go at some of them.
 Chapter 3 Pg20
work through this chapter making notes and making sure you
understand these very important processes. There are several experiments
which you need to familiarise yourself with.
Osmosis
• Define osmosis as the diffusion of water molecules from a region of their higher concentration (dilute solution) to a
region of their lower concentration (concentrated solution), through a partially permeable membrane
 Chapter 3 Page 23 Osmosis is VERY important in terms of water uptake
REMEMBER that diffusion can apply to any small molecule but osmosis only
applies to the movement of WATER and occurs across a partially permeable
membrane. Make sure you thoroughly understand this.
 You should be able to define osmosis as the diffusion of water molecules
from a region of their higher concentration (dilute solution) to a region
of their lower concentration (concentrated solution), through a partially
permeable membrane
• Describe the importance of osmosis in the uptake of water by plants, and its effects on plant and animal tissues
plants
 The movement of water is very important to plant and animal cells Chapter 3 Pg 25
and 26 Page 30. Make some simple notes on this and how water allows plants to
support themselves without a skeleton.
 Make notes on the importance of osmosis to plants and animals form
page 25-26.
• Describe and explain the importance of a water potential gradient in the uptake of water by
 It is important that you understand that a water potential gradient is set
up in plants which allows them to take up water
Active Transport
Chapter 3 Page 29
• Define active transport as movement of ions in or out of a cell through the cell membrane, from a region of their
lower concentration to a region of their higher concentration against a concentration gradient, using energy
released during respiration
• Discuss the importance of active transport as an energy-consuming process by which substances are
transported against a concentration gradient, e.g. ion uptake by root hairs and uptake of glucose by epithelial
cells of villi
Make sure you understand the importance of active transport in the uptake of ions
into plant roots and nutrients into the digestive system. Page 29-30
In both these situations the uptake is AGAINST the concentration gradient. (ie low
to high concentration) using energy supplied by respiration)
You should define active transport as movement of ions in or out of a cell
through the cell membrane, from a region of their lower concentration
to a region of their higher concentration against a concentration
gradient, using energy released during respiration
Try and find out how the movement of substances in and out of cells is affected by
TEMPERATURE, CONCENTRATION GRADIENT, AND SIZE (SURFACE
AREA TO VOLUME RATION)
ASSIGNMENT

Try the experiment on page 28. Write this up in full. Refer to the document called
‘writing up experiments’ and send it to me. Explain what is happening in terms of
osmosis and the movement of water. Send me your explanation of this and
your experimental write up as your first piece of work.