2 Organisation of the Organism

Nucleus

Controls all cell activity and contains DNA

Cell Membrane

Controls what leaves and what enters the cell

Mitochondria

Site of aerobic respiration in order to release energy

Ribosomes

Protein Synthesis

Cytoplasm

Site of chemical reactions

RER (rough endoplasmic reticulum)

Produces protein

Large Vacuole

Provides a turgor pressure which pushes out on the cell membrane which then pushes on the cell wall

Chloroplasts

Site of photosynthesis. Contains a green pigment called chlorophyll which absorbs light energy and converts it into chemical energy.

Cell Wall

Supports the cell

Animal Cell

• Nucleus

• Cell Membrane

• Mitochondria

• Ribosomes

• Cytoplasm

• RER

Plant Cell

• Nucleus

• Cell Membrane

• Mitochondria

• Ribosomes

• Cytoplasm

• RER

• Cell wall

• Large vacuole

• Chloroplasts

What does a plant cell have that an animal one doesn’t?

• Cell wall

• Large vacuole

• Chloroplasts

Bacterial cell

• Cell wall

• Chromosomal DNA (circular DNA)

• Flagellum

• Ribosomes

• Cytoplasm

• Plasmid (small loop of DNA which is antibiotic resistant)

• Cell membrane

• SOME HAVE CHLOROPLASTS

Fungal cell

• Nucleus

• Cell membrane

• Cell wall made from chitin

• Mitochondria

• Ribosomes

• Cytoplasm

Protoctist cell

• Nucleus

• Ribosomes

• Cell membrane

• Mitochondria

• Cytoplasm

• Contractile vacuole (involved in regulating water within the cell)

• SOME HAVE CHLOROPLASTS

• SOME HAVE FOOD VACUOLES

Virus Cell

• 1 strand of DNA or RNA

• Protein coat

• SOME HAVE AN ENVELOPE

Specialised cell

A specialised cell is a cell that is adapted to carry out a specific function

How are new cells produced?

New cells are produced by division of existing cells

RED BLOOD CELL

RED BLOOD CELL

Function

Transport oxygen

Adaptations

• No nucleus to increase the amount of space for haemoglobin

• Contains a chemical called haemoglobin which is used to pick up and transport oxygen

• Biconcave shape - increases the surface area and allows more oxygen to be carried around the body and allows for a more efficient diffusion of oxygen

SPERM CELL

SPERM CELL

Function

Fertilise the ovum (reproduction)

Adaptations

• Acrosome containing digestive enzymes - facilitates and allows the sperm to penetrate the egg’s cell membrane and fuse the nuclei

• Many mitochondria - provides the sperm with sufficient energy to swim and to fertilise the egg

• Haploid nucleus - contains only half the usual number of chromosomes

• Flagellum - Allows the sperm to swim to the egg

OVUM

OVUM

Function

To be fertilised (reproduction)

Adaptations

• Cell membrane - changes after fertilisation by a single sperm so that no more sperm can enter (the zona pellucida hardens allowing this to happen)

• Haploid nucleus - contains half of the usual genetic material

• Cytoplasm - the amount is increased because it needs to contain nutrients for the growth of the early embryo

NERVE CELL

NERVE CELL

Function

• Sends messages in the form of electrical impulses

• Conduction of electrical impulses

Adaptations

• Many endings allowing it to connect to other neurons

• Long fibre - can carry impulses long distances from different parts of the body to the central nervous system

• Axon covered with a fatty layer (myelin sheath) which insulates the nerve cell and speeds up the nerve impulses

CILIATED EPITHELIAL CELL

CILIATED EPITHELIAL CELL

Function

Moves mucus up the throat (trachea and bronchi)

Adaptations

• Many mitochondria

• Cilia are extensions of the cell membrane and are hair-like structures which beat to move mucus and trapped particles up the throat

ROOT HAIR CELL

ROOT HAIR CELL

Function

Absorption of water and mineral ions from the soil

Adaptations

• No chloroplasts as they are not needed because the cell is found underground

• Root Hair- increases surface area of cell to ensure maximum absorption of water and mineral ions

• Vacuole

• Thin cell walls - to ensure water moves through quickly

• Packed with mitochondria which releases energy needed for active transport

XYLEM CELLS

XYLEM CELLS

Function

Conduction of water through the plant; supports the plant

Adaptations

• Walls become thickened with a substance called (lignin) so they are able to support the plant

• No top and bottom walls - continuous column of water running through

• Cells are dead with no organelles to allow for a free passage of water

PALISADE MESOPHYLL CELL

PALISADE MESOPHYLL CELL

Function

Photosynthesis

Adaptations

• Packed with chloroplasts to ensure for maximum photosynthesis

• Column shape to maximise absorption of sunlight and fit as many in a layer under the upper epidermis of the leaf as possible

LEVELS OF ORGANISATION IN A MULTICELLULAR ORGANISM

LEVELS OF ORGANISATION IN A MULTICELLULAR ORGANISM

Cell

Basic functional and structural units in a living organism

Tissues

Groups of cells of similar structure working together to perform the same function

Organs

Made from different tissues working together to perform a specific function

Organ System

Groups of organs with related functions, working together to perform bodily functions

Order of organisation

cell →tissues →organ →organ system →organism

CONVERSION OF UNITS

CONVERSION OF UNITS

cm → mm

x10

mm → um (micrometer)

x1000

um (micrometer) → nm (nanometer)

x1000

MAGNIFICATION

MAGNIFICATION

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