Biology B7 OCR 21st century

These are detailed revision notes which i have created for B7 OCR 21st century.

All these notes follow the specification to make sure everything is covered!!

Enjoy and feedback!

HideShow resource information
  • Created by: Mona
  • Created on: 28-09-14 17:42
Preview of Biology B7 OCR 21st century

First 306 words of the document:

B7 ­ Further Biology
B7.1 Peak performance ­ movement and exercise
Vertebrates are animals that have an internal skeleton ­ those that do not have an internal skeleton
are called invertebrates. In humans and other vertebrates, the skeleton has two functions:
Support ­ the skeleton enables us to stand as well as enclosing important organs for
protection e.g. the brain is enclosed by the skull and the ribs enclose and protect the heart
and lungs
Movement ­ the skeleton enables complex movement, from standing to sitting and from
walking to running
Muscles can only move bones by contracting ­ so two muscles working in opposition to one another
are needed to move an arm up and down, i.e one muscle contracts while the other muscles contracts
relaxes ­ they work in antagonistic pairs.
For example:
To lift the lower arm, the biceps contracts and the triceps relaxes
To lower the arm, the triceps contracts and the biceps relaxes
A joint is where two bones meet and work together ­ the bones have to be connected in some way
that allows them to move also staying in the same place relative to each other. Joints are adapted to
allow smooth movement and to resist the effects of wear and tear
The different components serve different functions:
Part of the
Function
joint
Cartilage (which is smooth) prevents bones from rubbing together and
Cartilage
reduces friction
Synovial This helps to lubricate the joint and reduces friction
fluid
Ligaments The ligaments (which are elastic) help to stabilise the joints during movement
They transmit the forces from contracting muscles to the bones near the joint ­ they
Tendons
are a tough fibrous tissue made from collagen

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Taken together, the specific properties of each part of a joint enable it to function correctly ­ if there
is a problem with one part, the joint will not work correctly.
Exercise programmes can be put together by doctors, nurses, physiotherapists, personal trainers or
other experienced specialists ­ these exercise regimes can be used to train for a sport or to treat a
condition such as obesity.…read more

Page 3

Preview of page 3

Here's a taster:

A sprained knee can be the result of a sudden twist
A wrist can be sprained by falling on an outstretched hand
The symptoms of sprains include the following:
Swelling ­ due to fluid building up at the site of the sprain
Pain ­ the joint hurts and may throb
Redness and warmth ­ caused by the increased blood flow to the injured area
Being unable to move the joint or put weight on it
When someone suffers a sprain the priority is to reduce…read more

Page 4

Preview of page 4

Here's a taster:

Blood is a mixture of different components:
Plasma ­ the liquid part of the blood ­ it transports:
Nutrients (e.g.…read more

Page 5

Preview of page 5

Here's a taster:

Blood flows at high pressure from the heart in the artery - the blood reaches its destination via
arterioles that branch off the artery and into the capillary beds that surround cells
By the time blood reaches the
capillary beds from an artery, it is
at high pressure and this forces
blood plasma out ­ the plasma
leaves the capillary and becomes
tissue fluid.
As the blood plasma moves
through the capillary bed towards
the vein pressure drops and stops
plasma being squeezed out.…read more

Page 6

Preview of page 6

Here's a taster:

If the temperature of the body is TOO HIGH then heat needs to be transferred to the environment ­
this is achieved through sweat being produced by sweat glands which cools the body when it
evaporates.
Vasodilation is the widening of the blood vessels (capillaries) that run very close to the surface of
the skin.…read more

Page 7

Preview of page 7

Here's a taster:

This an example of effectors working antagonistacally ­ which means that they do opposite things
­ this allows a more sensitive and controlled response.
Glucose is needed for respiration ­ when we eat foods containing carbohydrates, enzymes are
needed to break them down into monomers.
Processed foods, compared to fresh foods are foods that have been changed from their naturally
occurring state to make them healthier and/or for convenience.…read more

Page 8

Preview of page 8

Here's a taster:

B7.4 What can we learn from natural ecosystems?
In a perfect closed loop system no material enter or leave the system ­ waste products from one
organism or process are used by another organism or process ­ the output from one part of the
system becomes the input to another part.…read more

Page 9

Preview of page 9

Here's a taster:

Vegetation is an essential part of many ecosystems:
Roots help to stabilise the soil ­ preventing it from being eroded by heavy rain (especially
in rainforests).…read more

Page 10

Preview of page 10

Here's a taster:

Human activities can unbalance an ecosystem, changing the inputs and outputs so much that the
ecosystem can no longer adapt ­ this means that the system is no longer a closed loop.
Eutrophication is where an excess of nutrients is put into a system, causing the productivity of the
system to increase while causing the balance of organisms to change, often drastically and
irreversibly.…read more

Comments

taqinisa

absolutely fabbbb ty

danai_c

I love you so much! You have gotten me through basically all my science exams!!! :))))

Similar Biology resources:

See all Biology resources »See all resources »