year 10 biology term 3 week 1

7/27/2019 Year 10 Biology Term 3 Week 1

1/26


2/26


3/26


4/26


5/26

Adult males and females have slightly

different skeletons.

Male skeletons have slightly thicker andlonger

leg and arm bones while female skeletons

have a wider pelvis and a larger space

within the pelvis to allow a baby to travel

through more easily at birth.


6/26

Bone is a living material and can repairitself when it is broken or fractured.

Small bones such as the ribs can repair themselves

Quickly but a large bone such as a

femur can take a long time.


7/26

If a child's diet is low in calcium or vitamin D

then the bones will grow but ossification is notcompleted.

The adult bones are deformed and weak sothey fracture easily.

This deficiency disease is called rickets. Many women suffer from osteoporosis after the menopause. This is where the amount of mineral in the

bone decreases so the bones are weakened.


8/26

The adult human skeleton is made up of

206 bones. A baby is actually born with about 300

bones but many fuse together as it growsup.


9/26

In the human embryo the entire skeletonis made of cartilage,

a firm but elastic material (in an adult,cartilage supports the ear).

Cartilage is made up of tough non-elastic fibres called collagen,

mixed with stretchy elastic fibres.


10/26

Gradually the bones develop by depositing a hardmineral called calcium phosphate. This is calledossification.

The final bone is made up of this mineral and the tough

collagen fibres.

Why is bone made up of two completely differentmaterials?

If bone did not have the collagen fibres in it then it wouldbe too rigid

and would shatter very easily. If bone did not have the minerals in it then it would be too

flexible

and could not support and protect other parts of thebody.


11/26

If bone did not have the collagen fibres

in it then it would be too rigid and would shatter very easily.

If bone did not have the minerals in it

then it would be too flexible and could not support and protect other

parts of the body.


12/26

In your booklabel each ofthese 19 bones


13/26

1.Skull

2.Neck vertebra

3.Clavicle (collar bone)

4.Humerus

5.Scapula (shoulder

blade)

6.Sternum7.Rib

8.Lumber vertebra

9.Radius

10.Ulna

11.Carpals (wrist bones)

12.Metacarpals

13.Femur

14.Patella (knee cap)

15.Tibia (shin bone)

16.Fibula

17.Tarsals18.Metatarsals

19.Pelvis


14/26

1. What are the two types of bone?

2. What is the vertebral column made up of?

3. Label the synovial joint on your sheet

4. What is the role of the synovial fluid?

5. Apart from the elbow and the knee, whatother joints in the body are like hinge joints?

6. Apart from its structural and mechanicalfunctions, what other important function doesthe skeleton have?

7. Which parts of the skeleton are concernedwith both protection and movement?


15/26


16/26


17/26


18/26


19/26

Where two bones meet they form a joint. It may be a fixed joint - hip girdle and the

vertebral column or a movable joint as in

the knee. Two important types of movable joints are

ball and socket joints and the hinge jointsof the elbow and knee.

The ball and socket joint allowsmovement forwards, backwards andsideways, whereas the hinge joint allowsmovement in only one direction.


20/26

Where the surfaces of the bones in a joint rubover each other, they are covered with smoothcartilage which reduces the friction betweenthem.

Friction is also reduced by a thin layer oflubricating fluid calledsynovial fluid.

(Movable joints are sometimes called synovialjoints).

The bones forming the joint are held in place bytough bands of fibrous tissues called ligaments.Ligaments keep the bones together but do notstop their various movements.


21/26

The bones forming the joint are held in place bytough bands of fibrous tissues called ligaments.Ligaments keep the bones together but do notstop their various movements.

The type of cartilage covering the surfaces ofbones in a joint is firm but softer than bone.

It contains fibres but no mineral salts.

It forms a smooth, slippery surface.

Tendons and ligaments consist of tough collagenfibres, which makes them flexible but very strongand resistant to stretching.

http://www.purchon.com/biology/flash/elbow.swf
http://www.purchon.com/biology/flash/elbow.swfhttp://www.purchon.com/biology/flash/elbow.swf


22/26


23/26

Lignin orlignen is a complex chemicalcompound most commonly derived from wood,and an integral part of the cell walls of plants

and some algae. (Please note that cellulose is

also an important part of the cell wall in plants). The term was introduced in 1819 by de Candolle

and is derived from the Latin word lignum,

meaning wood.

It is one of the most abundant organic polymerson Earth, exceeded only by cellulose, employing30% of non-fossil organic carbonand constitutingfrom a quarter to a third of the dry mass of wood.See below to see what the a molecule of ligninlooks like.


24/26


25/26


26/26

This has a similar effect to inflating a soft bicycle tyre. Thetyre represents the firm cell wall, the floppy inner tube islike the cytoplasm and the air inside corresponds to thevacuole. If enough air is pumped in, it pushes the innertube against the tyre and makes the tyre hard. A plant cellwith the vacuole pushing out on the cell wall is said to beturgid and the vacuole is exerting turgor pressure on thecell wall.

If all the cells in a leaf and stem are turgid, the stem will befirm and upright and the leaves held out straight. If thevacuoles lose water for any reason, the cells will lose theirturgor and become flaccid. A leaf with flaccid cells will belimp and the stem will droop. A plant which loses water tothis extent is said to be wilting.

year 10 biology term 3 week 1

Documents