cell biology Flashcards
explain how the lungs are adapted for efficient exchange of gases by diffusion
- it has many alveoli which provide a large surface area to volume ratio
- thin capillary walls which provides a short diffusion distance/path for oxygen and carbon dioxide
- good blood supply to remove oxygenated blood quickly and bring carbon dioxide to the lungs quickly
- breathing mechanism moves air in and out to bring in fresh oxygen and remove carbon dioxide
explain what therapeutic cloning is and why its not rejected by patients
- a therapeutic clone can be created by removing the nucleus from the patients cell and putting it into an empty egg cell ( enucleated egg)
- the clone has identical DNA to the patient
- stem cells are removed from the cloned embryo to treat the patient and are not rejected by their body as the stem cells contain the same genes as the patient
- they can be used to treat medical conditions e.g. diabetes
explain how the human circulatory system is adapted to supply oxygen to the tissues and remove waste products from the tissues
supply oxygen to the tissues:
- the heart pumps deoxygenated blood to the lungs in the pulmonary artery so that oxygen can diffuse into the blood from air in the alveoli
- the oxygenated blood returns to the heart via the pulmonary vein, where muscles pump oxygenated blood to the body via the aorta which is an artery. arteries carry oxygenated blood to tissues and they branch into capillaries. capillaries have thin walls which allows to be delivered to cells quickly and for waste products like carbon dioxide to diffuse out of cells and into the blood plasma so it can go back to the heart via the vena cava
describe the steps of embryonic stem cell treatment
- extract embryonic stem cells from early embryos
- grow them in a lab
- stimulate them to differentiate into whichever type of specialised cells we want
- give them to the patient to replace their faulty cells
