Organisation

Question 1

What test would we use to detect sugars

Answer 1

Benedicts test

Question 2

How does Benedicts test work

Answer 2

Add benedicts solution to food
-heat in a water bath
Results:

Green means little to no reduced sugars
Yellow means a bit of reduced sugers
Orange means a modest amount of reduced sugars
Red means a lot of reduced sugars

Question 3

Hazards of Benedict’s solution

and how to remove them

Answer 3

It is irritant
Avoid contact with skin and eyes
can counteract hazards wear safety goggles

Question 4

What test would we use to detect starch

Answer 4

Iodines solution

Question 5

How would we use iodine solution to test for starch?

Answer 5

To test for iodines solution just pour it onto the food sample

Question 6

Diffusion definition

Answer 6

When particles spread out from a region of higher concentration to a region of lower concentration

Question 7

What factors decide on how quickly organisms can absorb substances and how many substances they need

Answer 7

Surface area for how quickly they can absorb substances

Volume of organism of how many substances it requires

Question 8

What is a problem that multicellular organisms face as they increase in size

Answer 8

Their surface area does not increase as fast as the volume. Insufficient surface area to meet their needs.

Their volume increases diffusion is not quick enough to move substances to where they’re needed in the organism’s body

Question 9

Their surface area does not increase as fast as the volume. Insufficient surface area to meet their needs.

SOLUTION to this problem

Answer 9

Body systems that add additional absorbing area to exchange surfaces

Question 10

A transport system is

Answer 10

when an organisms surface area to vol ratio is too small. diffusion is not quick enough to move substances to where they’re needed in the organism’s body

Question 11

How is the effectiveness of exchange surfaces in plants and animals increased by having what adaptations for surface area

Answer 11

The flattened shape of structures such as leaves

The alveoli in the respiratory system

The villi in the digestive system

Question 12

A short distance required for diffusion. (Adaptations

Answer 12

The membranes of cells
The flattened shape of structures such as leaves

The walls of blood capillaries are one cell thick

The epithelia of alveoli in the respiratory system and the villi in the small intestine are only 1 cell thick

Question 13

Adaptations for the lungs effective surface exchange and small intestines

Answer 13

The network of blood capillaries that surround each alveolus in the lungs

The network of blood capillaries in each villus in the small intestine

Question 14

What does moving and ventilated surfaces mean

Answer 14

That a steep concentration gradient can be maintained. This increases effective exchange

Question 15

The human lungs provide an exchange surface adapted for

Answer 15

Absorbing oxygen needed for respiration into the blood from the air

Transferring carbon dioxide produced by respiration from the blood into the lungs then the air

Question 16

How are the rubs moved

Answer 16

by two sets of intercostal muscles which raise and lower the ribcage

Question 17

Describe how the lungs are enclosed

Answer 17

There is a muscular diaphragm below the lungs. The lungs are sealed within two airtight pleural membranes. These wrap around the lungs and line the rib cage.

Question 18

What helps keep the trachea open

Answer 18

Rings of cartilage in the walls of the trachea.

Question 19

Order of size in from trachea and down

Answer 19

trachea –> bronchi –> bronchioles –> cluster of alveoli.

Question 20

Alveoli are adapted to provide a very large surface area for gaseous exchange how

Answer 20

Small size - each alveolus is small sphere areound 300 μm in diameter. Giving it a larger surface area to volume ratio than larger structures

around 700 million alveoli

Question 21

Total surface area of the alveoli is around

Answer 21

70^2 meters

Question 22

How are alveoli adapted for diffusion

Answer 22

There is a short diffusion path - the walls of blood capillaries and alveoli are just once cell thick.

The alveoli are also lined with the thin film of moisture.

Gases dissolve in this water, making the diffusion path even smaller

Question 23

How is the ventilation of the lungs and blood flow through the surrounding capillaries means?

Answer 23

Gases are being removed continually and steep concentration gradients are set up for gases to diffuse

Question 24

Ventilation process (6)

written response
bloody think mate
f what ya feel

Answer 24

• Diaphragm pulling downwards and intercostal muscles contract moving the rib upwards and outwards move to create a lower air pressure in the lungs than that outside the body. Air then rushes into the lungs

Volume of the thorax increases so pressure decreases and air is drawn into the lungs

-Diaphragm relaxes and moves up intercostal muscles relax - The ribs move downwards and outwards.

Volume of the thorax decreases so pressure increases and air leaves the lungs

Question 25

Breathing for fishies (3)

Answer 25

Water flows through mouth
Water flows over the gills
Water leaves through the operculum

Question 26

Exchange of gases in fishies is very efficient because of

Answer 26

The large surface area of the gills

The large surface area of the blood capillaries in each gill filament

The short distance required for diffusion the outer layer of gill filament

The short distance required for diffusion

The outer layer of the gill filaments and the capillary walls are just one cell thick

The efficient ventilation of the gills with water there is a counter current flow of water and blood.

Question 27

The moving blood and ventilated gill surfaces mean

Answer 27

that gases exchanged are continually removed oxygen enters the blood and carbon dioxide removed to the water. High concentration gradients can be maintained

Question 28

The systemic circulation transports

Answer 28

-oxygen and nutrients to the body

-carbon dioxide and other wastes away from cells

Question 29

Why is the systemic circulation under high pressure

Answer 29

It has to deliver blood to the extremities of the body

Question 30

Why is the pulmonary circulation under low pressure

Answer 30

The blood is delivered to the lungs only, which are very close to the heart

In a healthy person this lower pressure is optimum for the diffusion of gases.

Question 31

How could valves be faulty:

A valve may not…

Answer 31

• open as wide as it should, restriction blood flow through the heart - this means less blood reaches the body, pressure builds up and the lungs can swell with fluid

-Close properly and allow blood to leak back through into the atrium

Question 32

How can you diagnose the problems for a faulty valve

Answer 32

heart scan

Question 33

Symptoms of faulty valves

Answer 33

Shortness of breath, dizziness, rapid heart rate and chest pain

Question 34

What can faulty valves lead too

Answer 34

Heart falure

Question 35

What can faulty valves lead too

Answer 35

Heart failure

Question 36

Faulty valves can be replaced with

Answer 36

• With a biological valve from a human donor or made from animal tissue from a pig or cow.

-With a mechanical valve made from strong, durable materials

Question 37

Advantages of mechanical valves + disadvantages

Answer 37

Advantages: Last longer
Disadvantages: More likely to blood clot. The patient will need long term medication that prevents blood clots from developing.

Question 38

Biological valves disadvantage

Answer 38

More likely to wear out