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