B2.2 Challenges of Size - Animal Transport

Question 1

<p>What is surface area to volume ratio?</p>

Answer 1

<p>The surface of an area per unit volume of an object.</p>

Question 2

<p>In what format should surface area to volume ratio be presented?</p>

Answer 2

<ul> <li>It should be calculated as a ratio</li> <li>It should be simplified so volume = 1cm³</li></ul>

Question 3

<p>Why can a tapeworm rely upon diffusion alone to provide nutrients, where as multicellular organisms can not?</p>

Answer 3

<p>The larger the surface area to volume ratio the more easily and quickly nutrients can diffuse, as diffusion ratio's are small e.g the tape worm.</p>

<p></p>

<p>Increase size of organism = decreasesurface area to volume ratio, therefore diffusion distance becomes to great to allow an organism to meet the cells' demands.</p>

Question 4

<p>State three examples of adaptations to animal cells to improve surface area to volume ratio.</p>

Answer 4

<p>Villi - intestines</p>

<p>Microvilli - Cilliated epithelial cells lungs</p>

<p>Alveoli - spherical shape</p>

Question 5

<p>State adaptations to plants to increase surface area to volume ratio.</p>

Answer 5

<p>Broad flat leaves - increase SA for capturing light & gaseous exchange via the stomata</p>

<p>Root hair cells</p>

Question 6

<p>Explain the adaptations of the lungs to maximise the rate at which oxygen enters the body.</p>

Answer 6

<ul> <li>Single cell wall</li> <li>Ventilation moves air in and out of lungs to maintain concentration gradient</li> <li>Capillary network means good blood supply, which maintains concentration gradient</li> <li>Spherical shape increases surface area</li></ul>

Question 7

<p>Explain the adaptations of the villi to maximise the rate of diffusion and active transport in the small intestine.</p>

Answer 7

<ul> <li>Single cell wall</li> <li>Capillary network means good blood supply, which maintains concentration gradient</li> <li>Fingerlike shape increases surface area</li> <li>Microvilli increasessurface area further</li> <li>Many mitochondria to provide energy for active transport</li></ul>

Question 8

<p>Why are transport systems needed?</p>

Answer 8

<p>To transport a substance to where it is needed once it has diffused.</p>

Question 9

<p>Name four transport systems in humans.</p>

Answer 9

<p>Respiratory</p>

<p>Circulatory</p>

<p>Digestive</p>

<p>Endocrinology</p>

<p>Nervous</p>

<p>Urinary</p>

Question 10

<p>What is the circulatory system?</p>

Answer 10

<p>Heart and blood vessels</p>

Question 11

<p>How does the circulatory system of a fish compare to the human circulatory system?</p>

Answer 11

<p>The fish has a single circulatory system, humans have a double circulatory system.</p>

Question 12

<p>State the difference between oxygenated and deoxygenated blood.</p>

Answer 12

<ul> <li>Oxygenated = high levels of oxygen</li> <li>Deoxygenated = low levels of oxygen</li></ul>

Question 13

<p>Name thethe three types of blood vessel shown below.</p>

Answer 13

<ul> <li>A = vein</li> <li>B = capillary</li> <li>C = artery</li></ul>

Question 14

<p>Name the adaptations of the three blood vessels below.</p>

Answer 14

<ul> <li>A = vein, thin outer wall, thin layer of muscle and elestic fibres, large lumen</li> <li>B = capillary, very small lumen, single cell wall</li> <li>C = artery,thickouter wall, thicklayer of muscle and elestic fibres, small lumen</li></ul>

Question 15

<p>Explain why humans are said to have a double circulatory system.</p>

Answer 15

<p>Blood is pumped out of the heart twice, once to the lungs and once to the rest of the body</p>

Question 16

<p>What are the benefits of having a double circulatory system?</p>

Answer 16

<ul> <li>Deoxygenated and oxygenated blood does not mix</li> <li>Blood is under higher pressure as it does not have to travel as far</li> <li>High pressure means the materials are transported around the body more quickly</li></ul>

Question 17

<p>State the difference between cardiac muscle and the muscles in the rest of your body?</p>

Answer 17

<ul> <li>Heart is made of cardiac muscle that contracts without recieving nerve impulses from our brain</li> <li>Muscle in the rest of your body (e.g in your arm) require a nervous signal to stimulate contraction</li></ul>

Question 18

<p>Describe the pathway through the human circulatory system.</p>

Answer 18

<ol> <li>Deoxygenated blood enters the lungs.</li> <li> <p>Oxygen enters the blood. CO₂ leaves.</p> </li> <li> <p>Blood enters the heart through the pulmonary vein, into the left atria.</p> </li> <li> <p>Blood is pumped through the heart from the left artria to the left ventricle, via the bicuspid valve.</p> </li> <li> <p>Blood is pumped out of the left ventricle through the Aorta and goes to the rest of the body.</p> </li> <li> <p>Oxygen diffuses out of the blood and CO₂ diffuses in.</p> </li> <li> <p>Blood enters the right atria of the heart through the vena cava.</p> </li> <li> <p>Blood is pumped through the heart from the right artria to the right ventricle, via the tricuspid valve.</p> </li> <li> <p>Blood is pumped out of the right ventricle, to return to the lungs via the pulmonary artery.</p> </li></ol>

Question 19

<p>Name the four key components of blood and their function.</p>

Answer 19

<ol> <li>Red blood cells - small biconcave cells that contain haemoglobin and have no nucleus to enable and maximise oxygen transport.</li> <li>White blood cells - large cells fight disease by making antibodies, or changing their shape to engulf pathogens.</li> <li>Platelets - tiny structures/fragments of cells that help blood to clot</li> <li>Plasma - Made up of 90% water, straw coloured fluid in which the other components of blood float within. Acts as a transport emdium for digested food, wast products, hormones and antibodies.</li></ol>

Question 20

<p>State the type of blood cell which is most common in the blood.</p>

Answer 20

<p>Red blod cells</p>