Biology EBIs

What I got wrong and why + improved answers

Cells, tissues and organs

• When a phagocyte engulfs a bacterium, it creates a vacuole and secretes digestive enzymes into this vacuole.
• The nucleus contains DNA/RNA and controls the cell's activities. That is better than saying "controls cell activities".
• Blood clotting prevents blood loss pathogens from entering the bodies - "microorganisms" is too vague
• Right ventricle pumps blood to the lungs
• Blood vessel with least oxygen is the vena cava

Digestion and diet

• Bile emulsifies fats and neutralizes digested food from stomach
• sunlight (not 'playing outdoors) boosts vitamin D levels which reduces the chance of rickets
• 'exercise' is not a component of a balanced diet. However, protein, carbs and fats (typically 1 mark each) are.
• Excess fat in a diet can lead to obesity and other problems
  • blood vessels clogged
  • high blood pressure
  • joint damage

Control of internal conditions

• Smaller SA to vol ratio, less heat is lost
• If muscles are kept warm, they can still contract, making them useful
• A arctic penguin's feet are outside its body but the muscles that control them are inside. Feet are controlled by tendons, which have to be strong and not elastic
• When penguins huddle together to keep warm, the obvious advantages are that they keep warm, protect themselves from the elements (primarily cold wind) and decrease the SA:Vol ratio further

Diseases and disorders

• Emphisema is a disease that causes the enlargement of the alveoli, where they lose a large amount of surface area and so results in breathlessness (lung transplant required)
• Coronary failure means the heart can't pump blood at the rate that it is required to (heart transplant required)
• Diabetes is a metabolic disease in which the pancreas can't produce enough insulin to regulate glucose levels in the blood (pancreas transplant)
• Hepatitis is a disease characterized by the inflamation of the liver (liver transplant)
• Poor vision can be fixed / improved with a surgery that involves replacing the cornea.
• In terms of organ donation, clones are better because they're always available, have no complications with relatives and there's no shortage.
• Smoking causes cilia to be damaged (not 'covered')
• Tar contains carcinogens that can…