CELLS
Learning Objectives
• that cells form tissues, and tissues form organs
• to name some important tissues in humans
• to explain the organisation of tissues using a model
• that there are different types of cell, adapted for different functions
• to use secondary sources of information
What are living organisms made from?Basically, all living things are made up of cells…
A group of CELLS makes up a TISSUE
A group of TISSUES makes up an ORGAN
A group of ORGANS makes up a SYSTEM
A group of SYSTEMS make up an ORGANISM
Muscle cells
Muscle tissue
Organ
System
Organism
What are living organisms made from?
Human Body TissuesEpithelial tissues• serve as membranes lining organs
and helping to keep the body's organs separate, in place and protected
Connective tissues• adds support and structure to the
bodyMuscle tissues• specialised tissue that can contractNerve tissues• generate and conduct electrical
signals in the body
Organ Systems
Circulatory systemOxygen is carried by blood, blood is pumped by the heart.
Organ Systems
Nervous SystemThe nervous system is responsible for sending, receiving, and processing nerve impulses throughout the body. Ex. brain, spinal cord
Organ Systems
Respiratory SystemIn the respiratory system, the lungs are the organs that take in the oxygen muscles need.
Organ Systems
Digestive SystemIn the digestive system, the stomach and the intestines are the organs that get sugars from the food you eat. Blood carries these sugars to the muscles.
Organ Systems
• Reproductive systemMajor Organs: Female: ovaries, oviducts, uterus, vagina and mammary glands. Male: testes, seminal vesicles and penis.
http://www.brainpop.com/science/diversityoflife/humanbody/
Singular cell organisms
• functions like respiration, feeding, moving, expelling wastes, reproduction, etc. are carried out by the single cell
• Ex. Amoeba, paramecium• http://www.youtube.com/watch?v=W6rnhiMxtKU
• http://www.youtube.com/watch?v=l9ymaSzcsdY&feature=fvw – p
ppp
Specialised Cells
• Some cells have very specialised functions• These cells have special features, or adaptations,
in order to carry out their special function
Root Hair Cell
• These cells are found near to the tip of the roots of plants• Most water and nutrients enter plants through them
It has a large surface area to speed up the absorption of water and mineral salts from the soil.
•http://www.brainpop.com/science/cellularlifeandgenetics/cellspecialization/
Research Poster
• You are going to be making a A3 poster with information about a specialised cell
• You need to use google to find images and websites to find out information on these cells.
• If you use a website, you must make a note of the address.
• Copy it and put it in a reference section in the corner of your poster!
Poster criteria
– Have a clear title and subtitles– Explain specialised cell function– Identify where the cell is found– Identify special features that help the cell
perform its specialised function– Have clear pictures– not have lots of text copied from a website– Have a reference section where you can put
your used websites in
Specialised cells
• Choose one or more from:– Sperm cell – Egg cell– Palisade cell– Ciliated cell– Nerve cell– Red blood cell– White blood cell
Specialised cells
Sperm cell – Designed to carry genetic information to an
egg – They have a tail which they use for swimming– They have a pointed head to penetrate the egg– The head of the sperm contains special
chemicals that help it penetrate the egg– They have little cytoplasm so they can swim
faster
Specialised cells
Egg cell– Designed to be fertilised– An ovum is large and bulky because no active
movement is needed - it just sits and waits for the sperm to find it
– It contains yolk (in the cytoplasm) which provides a large food store needed for the developing young organism once it's fertilised
– Once the sperm fertilizes the egg, the egg swells pushing away other sperm, so it can only be fertilized once
Specialised cells
Palisade cell– Designed for photosynthesis– They are tall and narrow so that lots of cells
can fit close together– They are found on the top side of a leaf - ideal
for good absorption of carbon dioxide and light - both are needed for photosynthesis
– They're packed with chloroplasts, which contain the green pigment chlorophyll, which is needed for photosynthesis
Specialised cells
Ciliated cell– To remove mucus, to remove bacteria, move
liquid over the cell's surface.– In humans, ciliated cells are found, for
example, in the lining of the windpipe, where they sweep mucus and dirt out of the lungs, and in the oviducts, where they move the ovum from the ovary to the uterus
– They have tiny hairs that beat to move things over the cell surface
Specialised cells
Nerve cell– To carry messages throughout the body – They are very long so they can carry messages
to different parts of the body– They have many branches at the end so they
can connect with many other nerve cells
Specialised cells
Red blood cells– To carry oxygen from the lungs to the parts of
the body where it is needed– They are shaped to give them a large surface
area so they can absorb oxygen more easily– The cytoplasm contains a chemical called
‘haemoglobin’ which carries oxygen– Have no nucleus so there is more room for
oxygen to be carried in the cell and hence around the body
– Their shape makes them flexible which means cells can squeeze through the thinnest of capillaries
Specialised cells
White blood cell– To help the immune system– Some are flexible, so they can engulf foreign
objects, viruses, bacteria and fungal infections– Some can remember dangerous infections, and
therefore protect against them better next time