The answer is B. Transmission electron microscope is the ideal tool to use to study the surface of preserved cells. The microscope has the ability to see extremely small structures and it can only be used to examine dead or preserved materials. This is because the specimen must be dehydrated before it can be examined.
Light microscope is used majorly to examine microbes while scanning electron microscope is used to observe a sample's surface topography and composition.
Answer:
Explanation:
Key developments in blood transfusion techniques
• Animal experiments over the years 1900-1916 gradually enabled transfusion to become the routine technique it is today. The key developments were:
• George Crile (1907) perfected the technique of transfusion from artery to vein using dogs, and described its application in 32 patients.
• Hustin (1914) showed that addition of sodium citrate could prevent blood from clotting and that citrated blood could be safely transfused into dogs.
• Richard Lewisohn (1915) determined the maximum amount of citrate that could be transfused into dogs without toxicity and thus determined the optimum concentration that could be added to blood for the best anticoagulant effect.
• Weil (1915) showed that citrated blood could be stored for 2 days and still be effective when transfused into guinea-pigs and dogs which had lost blood.
• Rous and Turner (1916) used rabbits to demonstrate that, with certain additives and proper treatment, citrated blood could be stored for 14 days and still be successfully transfused.
Through these animal experiments, the prolonged storage of blood without clotting thus became possible, so enabling the establishment of blood banks, and blood transfusion as a routine procedure.
Xx - female. Xy - male. egg already has an X chromosome so it depends on the other. If second one is X than it's a girl. If Y - a boy
Answer:
Enceladus its a moon in saturn
