B2.3

Question 1

What are the top two chambers and bottom two chambers in the heart

Answer 1

Top two are atriums, right and left, and bottom two are right and left ventricles

Question 2

What is septum

Answer 2

Muscle in centre of heart that separates left and right sides in heart

Question 3

What happens in right side of heart

Answer 3

Blood enters vena cava into right atrium and through the valves into right ventricle. Up through pulmonary artery and into the lungs.

Question 4

What halve separates the atrium and ventricles

Answer 4

atrio ventricular

Question 5

What’s special about the pulmonary artery

Answer 5

Only archery carrying de oxygenated blood, from the right ventricle to the lings

Question 6

What valve is between the ven cava and heart and the aorta and the heart

Answer 6

Semi lunar valves

Question 7

What happens in left side of heart

Answer 7

Blood enters left atrium through the pulmonary vein with oxygenated blood. Blood goes through strip ventricular valve into the left ventricle. Blood pumped through semi lunar valve through aorta and into the rest of the body

Question 8

What kind of muscle is the heart made of

Answer 8

Cardiac muscles

Question 9

What are the superior and inferior vena cavas

Answer 9

Superior, blood from above the heart eneters heart through here, blood from below heart enter it through inferior vena cava

Question 10

What are fossils

Answer 10

Preserved traces or remains of organisms that lived th us ands or millions of years ago

Question 11

What is the fossil record

Answer 11

The history of life on earth shown through changes in fossils

Question 12

Why are there gaps in the fossil record

Answer 12

Soft tissue organisms don’t have many fossils as most of their body decays when they die and many other organisms have the hard part of their bodies destroyed before they can be fossilised. There may also be other fossils we have yet to find

Question 13

What is the pentadactyle limb structure

Answer 13

Arm Kim's consisting from top to bottom
Humerus
Radius and ulna bones
Carpals
Phalanges

Question 14

What does the pentadactyl limb show us

Answer 14

All vertebrates evolved from one common ancestor and changed to adapt to their environment

Question 15

How do plants grow

Answer 15

The area beneath the tip of a shoot or root has cells called meristem. These cells are always dividing and elongating, this causes growth.

Question 16

What is special about meristem

Answer 16

The older meristem cells can differentiate like stem cells into other cells such as a leaf one with chlorophyll or a root hair cell

Question 17

Why can’t animals re grow limbs but plants can regrow leafs

Answer 17

Plants always have meristem than can differentiate into any cell, adults have a few stem cells and they can’t differentiate into all the different cells needed to regrow body parts

Question 18

Why is blood an organ

Answer 18

It is made up of lots of different cells that work together to carry out a function

Question 19

What is plasma

Answer 19

Yellow substances accounting for approx 55% of blood, it carries food substances, hormones and carbon dioxide

Question 20

What are red blood cells

Answer 20

Specialised cells in the blood accounting for approx 45% of blood and carry no oxygen, they have no nucleus to allow more room for the oxygen

Question 21

How do red blood cells carry oxygen

Answer 21

They contain haemoglobin that reacts with the oxygen in the air to form oxyhaemoglobin and then reverses the reaction at other cells to pass on the oxygen

Question 22

Why are red blood cells biconcave disc shaped

Answer 22

This this them a large surface area to volume area so lots of difffusion

Question 23

What are platelets

Answer 23

Fragments of other cells and they clot the blood when exposed to the air

Question 24

What are white blood cells and what do they do

Answer 24

Cells used for the bodies defence. Some produce antibodies that when release, surround the foreign cell and destroy it, others surround the foreign cells themselves to destroy it

Question 25

What is tissue

Answer 25

The thing formed when a group of the same type of specialised cells form a tissue

Question 26

What is an organ

Answer 26

Something containing several different types of tissue that work together for a particular function

Question 27

How does blood travel through the body

Answer 27

Blood enters heart from either superior or inferior vena cava. From here it goes through the semi lunar valves and into the right atrium. When it's full it goes through atrio ventricular valves and into the right ventricle. When this is full, it pumps it into the the pulmonary artery. Here it goes into the lungs and becomes oxygenated. Then it enters the pulmonary vein and into the left atrium through semi lunar valves. Then once it's full, goes through atrio ventricular valves and into the left ventricle. When this is full, it pumps it into the aorta which takes it around the body. Then it goes from arteries through capillaries and into veins. Then they go back to vena Ca as

Question 28

What is the circulatory system

Answer 28

The system made of arteries, veins, capillaries and the heart

Question 29

Properties of capillaries

Answer 29

Single cell thick walls for easy diffusion

Question 30

Properties of arteries

Answer 30

Thick muscular walls to deal with the pressure and thin space in the middle

Question 31

Properties of veins

Answer 31

Thin muscle walls as lower pressure, large space inside so less friction so blood flows easier

Question 32

What are the parts of the alimentary canal

Answer 32

``` Mouth Oesophagus Stomachs all intestine Pancreas Large intestine Anus Liver Gall bladder ```

Question 33

What happens at the mouth

Answer 33

Food is chewed into small pieces to increase surface area for enzymes. Amylase in Sylvia stars breaking down carbs into sugars. Spit helps lubribcate food and tounge rolls it into a bolus before it is swallowed

Question 34

What happens in oesophagus

Answer 34

Peristalsis pushes the bolus into the stomach

Question 35

What happens into the stomach

Answer 35

Peristalsis churns it up into a paste and the acid helps break it down. Pepsin breaks down proteins into amino acids

Question 36

What happens in small intestine

Answer 36

Large insoluble molecules are broken into small soluble ones. Lots of enzymes from pancreas help break down food into digestible sizes. Molecules of processed food diffuse into the blood through the villi.

Question 37

What happens in the pancreas

Answer 37

The organ makes the digestive enzymes and releases them to where they need to go

Question 38

What happens in large intestine

Answer 38

Undigested food passes through here. Water diffuses into the blood and all that remains is the poo

Question 39

What happens at anus

Answer 39

End of the alimentary canal where poo exits the body

Question 40

What happens at the liver

Answer 40

Blood with digested food passes through here to be processed. Some molecules are broken down even more, some built up into larger molecules. Bile is also made which helps break down fats.

Question 41

What happens at gall bladder

Answer 41

Stores the bile made by the liver and releases it when nesicary

Question 42

How are carbs digested

Answer 42

Carbohydrases break down carbs, starches into simple sugars. Amylase breaks carbs into simple sugars and other carbohydrases break the simple sugars into glucose

Question 43

How are proteins digested

Answer 43

Proteins are broken into amino acids which the body uses to make its own proteins. Pepsin is a protease made in the stomach and works at the acidic conditions, 2-3pH. However in the small intestine, trypsin breaks down proteins as it's more alkali, ph8.

Question 44

How are fats broken down

Answer 44

Bile emulsifiers fatty globules into smaller ones to give them a larger surface area, lipases then break them down into fatty acids and glycerol

Question 45

What does bile do

Answer 45

Emulsifies the fatty globules, makes poo brown and makes small intestines alkali, rather than acidic

Question 46

Why are villi so important

Answer 46

They dramatically increase the surface area of the small intestine which means that a lot more diffusion can take place than if it was a smooth surface s

Question 47

What are villi and what do they do

Answer 47

Each villus is one cell thick and has a good network of capillaries making them ideal for diffusion. They re single cell thick for easy diffusion and the good network of capillaries means once a substance diffuses into it, the blood takes it away quickly so the concentration gradient between the villi and food means the food is always diffusing into the villi

Question 48

What does coelliac disease do

Answer 48

Villi are lost or covered up so the surface area of the small intestine is reduced so less diffusion, this makes victims of the disease very skinny and weak

Question 49

What are probiotics

Answer 49

Foods containing friendly bacteria such as lactobacillus and bifidobacteria, these supposibly make you healthier

Question 50

What are plant stanol esters and what do they do

Answer 50

They are oily substances found in plants which stop the small intestines absorbing cholesterol which helps reduce heart problems and heart failure

Question 51

What are prebiotics

Answer 51

They can't be absorbed by us but are beneficial for probiotics, acting like food. Ingesting these increase number of probiotics in the body