Common Systems

Question 1

What does haemoglobin do

Answer 1

In red blood cells and makes them red, when it goes into the lungs it reacts with oxygen to make oxyhemoglobin and when it gets to where oxygen is needed it reacts back to oxygen and haemoglobin to the oxygen can diffuse out.

Question 2

What is blood made of and functions

Answer 2

55% plasma, carries dissolved substances ,C02, food substances and hormones.
White blood cells <1%, used in immune system, make antibodies that fight foreign cells and kill diseases.
Red blood cells 45%, carries 02 around body, disk shape for higher surface area so higher surface area to volume ratio meaning more space for diffusion and no nucleus for more space to have more 02

Question 3

Where and what is bile

Answer 3

Something that is used to break down large bits of fat into smaller pieces that the lipase then beak down into smaller soluble substances. Also used to neutralise substances leaving the stomach and going into the small intestine for the so enzymes can work. Made in liver and stored in gall bladder where it is released Into the small intestine when it’s needed

Question 4

What is the pentadactyl limb structure

Answer 4

A 5 fingered structure that is common in many animals such as Humans, whales and horses suggesting we had a common ancestor and have evolved into separate species. Consists of humerus, radius and ulna, carpals and phalanges.

Question 5

What is a fossil

Answer 5

The remains of organisms that lived thousands or millions of years ago

Question 6

Why are fossils useful

Answer 6

They help scientists discover organisms that once lived in the past and they can use them for evidence such as backing evolution

Question 7

What the processes are in growth

Answer 7

When a cell splits into two and when those two grow bigger

Question 8

What does differentiate mean

Answer 8

When a cell changes and become specialised for a specific purpose

Question 9

What are and where are meristem

Answer 9

This area is found in the tips of plants. It is an area where the cells keep dividing and elongate for growth

Question 10

What are special about cells in meristem

Answer 10

After they have grown and become older, they can differentiate into any plant cell

Question 11

Similarities and differences in growth in plants and animals

Answer 11

Similarities
Both grow through cell division

Difference
Animals stop growing, plants always grow
Adult stem cells can only differentiate into certain cells, meristem cells can become anything

Question 12

Why is haemoglobin so important

Answer 12

Without it in red blood cells, there won’t be anything for the oxygen to react with so it won’t enter the blood meaning nothing will work as there is no oxygen int he body

Question 13

What is an organ

Answer 13

Something with a group of specialised tissue used to carry out a specific function

Question 14

What is the cycle of blood

Answer 14

Goes from tissues as de oxygenated blood, into heart which pumps it into the lungs
Become oxygenated blood and goes back to the heart
Pumps it around the body to tissue
Cycle starts again

Question 15

What is the superior and inferior vena cava and what do they do

Answer 15

Superior vena cava brings blood from upper body to the heart

Inférieur vena cava brings blood from lower body to the heart

Question 16

What is the septum

Answer 16

A piece of muscle separating the halfs of the heart

Question 17

Why are there valves in the heart

Answer 17

To stop backwards blood flow

Question 18

What happens to blood in the right side of the eart

Answer 18

Deoxygenated blood is taken into the right atrium by one of the vena cava
When the atrium is full, it contracts, pushing the blood into the right ventricle
When this is full, it contracts and pushes the blood into the pulmonary artery
This carries on into the lungs where it become oxygenated

Question 19

What happens to blood in the left side of the heart

Answer 19

Blood goes from the lungs into the pulmonary vein which takes it into the left atrium
When the atrium is full, it contracts and forces the blood into the left ventricle
When the ventricle is full, it pushes blood into the aorta which is a large blood vessel which carries the blood around the body.

Question 20

Why is the muscle in the left of the heart thicker than the right

Answer 20

Because the right only has to push blood into the lungs but the left side has to push it around the whole body

Question 21

What are blood vessels

Answer 21

Tubes in the body that carry blood around the body

Question 22

What are the 3 types of blood vessels

Answer 22

Veins
Arteries
Capillaries

Question 23

What are veins and features

Answer 23

They carry de oxygenated blood (apart from pulmonary vein) to the heart. They are wide and have thin walls as the blood flows slowly as there isn’t much pressure

Question 24

What are arteries and features

Answer 24

Apart from the pulmonary artery, they carry oxygenated blood away from the heart to the tissues. They have thick walls as they need to be under high pressure for the blood to reach every part of the body

Question 25

What are capillaries and feature

Answer 25

They are small, single cell walled blood vessels that allow substances such as oxygen to diffuse from the blood and into tissue. They connect arteries to veins

Question 26

What are the parts of the alimentary canal and what do they do

Answer 26

Mouth - takes in food, chews it into a bolus, amalease break down starch into sugars
Oesophagus - peristalsis pushes the bonus to the stomach in a wave
Stomach - acid and enzymes digest the food, peristalsis churns it into a thick paste. Mostly protein digestion
Pancreas - makes and releases the digestive enzymes
Small intestine - enzymes break large insoluble molecules into smaller soluble ones, these are absorbed into the blood by villi
Gall bladder - bile is made and then stored in the liver
Large intestine - rest of the undigested food passes through this to the anus, water is réabsorbes leaving just poo
Liver - once molecules in small intestine have been absorbed by the blood, the blood is processed by the liver, some molecules are made smaller, some made larger, bile is also sometimes used on fats
Anus - where poo leaves the body

Question 27

What are the three main types of food molecules

Answer 27

Carbohydrates
Proteins
Fats

Question 28

What enzyme breaks up starch and what into and where are they found

Answer 28

Carbohydrases such as amylase which breaks them down into simple sugars such as glucose which can be absorbed. It is present in saliva and in the pancreas and small intestine

Question 29

What enzymes break down proteins, what into and where are they

Answer 29

Proteases, trypsin and pepsin. Pepsin is in the stomach and works best in low pH and trypsin is in the small intestine and works best at high pH. They break proteins down into amino acids which can be absorbed into the body to make new proteins

Question 30

What acids break down fats, where are they, what they do

Answer 30

Lipases break down fats into fatty acids and glycerol

Question 31

What is bile for and why is it important

Answer 31

2 uses
Used to physically break down large globules of fats and oils into smaller ones. It emulsifiers the fat. This is important as it increases the surface area, making it easy for the lipases.
It is also alkaline and is released into the small intestine, this neutralises the acidic matter from the stomach making it more alkali and suitable for enzymes such as trypsin

Question 32

How does digested food enter the blood

Answer 32

It diffusés into the blood thorough villi

Question 33

Why are villi finger shaped

Answer 33

To give them a large surface area for more efficient absorption of digested food. If the small intestine was smooth, like in coeliac disease, not much absorbtion would happen and you would become very thin

Question 34

Why do villi need a good capillary network

Answer 34

So the blood in the villi always has a lower concentration of food molecules than in the small intestine as it is always being moved away, this creates a steep concentration gradient so diffusion happens fast.

Question 35

What are probiotics

Answer 35

Friendly bacteria that are beneficial to you

Question 36

What are plant stenol esters

Answer 36

Oily substances found in plants. They stop the intestines absorbing choloestrol which can help reduce risk of heart problems

Question 37

What are prebiotics

Answer 37

Substances our body can’t digest but they act as food fro probiotics and encourage there growth. They are ingested in tablets and are shown to have health benefits.