Biology Chapter 2.2(Animals and Heart)

Question 1

What is surface area to volume ratio?

Answer 1

The surface area to volume ratio is the surface area per unit volume of an object.

Question 2

What is the relationship between SA:V ratio and diffusion?

Answer 2

The smaller the organism,the larger the SA:V ratio is so the diffusion distance needed is much smaller

The greater the organism,the smaller the SA:V ratio is meaning the greater distance needed for diffusion so it can’t always be used

Question 2

How do organisms increase diffusion at exchange surfaces?

Answer 2

In humans,we have alveoli in our lungs which increase the surface area for diffusion.

.Inside the small intestine,there a small villi structure which further increases surface area

Question 3

Why are transported systems needed?

Answer 3

Organisms require transport systems to carry certain materials to where they need to be.

Animals have the circulatory system which uses blood
.Plants have xylem and phloem tubes

Question 3

What does our circulatory system contain?

Answer 3

Our circulatory system contains our heart,blood and blood vessels and it is a closed system

Question 4

How does blood flow in the circulatory system?

Answer 4

Blood flows twice through the heart each circuit ,which is known as a double circulatory system.

Question 5

How do levels of oxygen change in our blood?

Answer 5

Red blood is oxygenated blood and blue blood is deoxygenated blood.

Question 6

Describe the purpose of the circulatory system?

Answer 6

Your heart pumps oxygenated blood to all your organs to be able to supply them with glucose and oxygens

.The waste product, CO2 is created

.It is then transported back into the bloodstream and pumped back through the heart as deoxygenated blood into the lungs to be exhaled

Question 7

Name the 3 types of blood vessels that transport blood

Answer 7

Arteries,veins and capillaries

Question 8

Describe the structure of an artery

Answer 8

.Thick outer wall
.Thick layer of muscle and elastic fibres
.small lumen
.smal lining

Question 9

Describe the structure of a vein

Answer 9

.Fairly thin outer wall
.Thin layer of muscle and elastic fibres
.large lumen
.Smooth lining

Question 10

Describe the structure of a capillary

Answer 10

.very small lumen which is sermi-permeable
.wall made of single layer cells

Question 11

Describe the function of an artery

Answer 11

Arteries carry blood away from the heart under high pressure

Question 12

Describe the function of a capillary

Answer 12

Capillaries link arteries and veins in tissues and organs and are near all the cells to allow easy diffusion

Question 13

Describe the function of a vein

Answer 13

Veins transport blood back to the heart

Question 14

Why is the arterial wall thick and muscular

Answer 14

To withstand blood of high pressure

Question 15

Why is walls of the vein thin

Answer 15

Blood pressure is low when entering the capillaries so a thick wall is not needed

Question 16

What tissue is the heart made of

Answer 16

It is made of cardiac muscle tissue

Question 17

Describe the structure of the heart

Answer 17

The heart has 4 key chambers;2 smaller chambers on the top which are the atria and 2 larger chambers on the bottom which are the ventricles

Valves separate the 4 chambers

Question 18

Describe the vessels within the heart

Answer 18

Vena cava-brings deoxygenated blood into the heart
pulmonary artery-deoxygenated blood to the lungs
aorta-carries oxygenated blood around the body
pulmonary vein-brings oxygenated blood from the lungs

Question 19

Describe the path blood takes through the double circulatory system

Answer 19

.Deoxygenated blood enters the right atrium.it is the pumped through the right ventricle into the lungs where it collects oxygen

.The blood then enters the heart through the pulmonary vein,then through the left atrium then ventricle and out through aorta to deliver the oxygen to all the cells.

Question 20

Describe the function/structure of red blood cells

Answer 20

small biconcave disc
.No nucleus
.Contain haemoglobin which carries oxygen
.They fit through the lumen of the capillaries cells to get the specific cells

Question 21

Describe the function/structure of white blood cells

Answer 21

.Large cells with nucleus
.Make antibodies which is used to help engulf microbes

Question 22

Describe the function/structure of plasma cells

Answer 22

plasma cells are made up of 90% water and lot of materials are transported by dissolving into the plasma .For example:
Digested soluble foods(amino acids and glucose)
.Waste products(CO2)
.Hormones and antibodies

Question 23

Describe the function/structure of platelets

Answer 23

Tiny structures that help the blood to clot