All the options are correct.
1. New ways to preserve and transport blood for blood transfusions were discovered.
2. Blood transfusion safety was improved.
3. Scientists discovered that elements of blood could be separated by centrifuge.
4. Scientists discovered that plasma could be preserved by freezing.
Karl Landsteiner
Karl Landsteiner was the man who discovered some of the human blood types in 1900 and 1901 at the University of Vienna.
Answer:
The correct answer is - 1. true, 2. true, 3. false, and 4. true.
Explanation:
1. Rod cells are the photoreceptors present in the retina that are hyperpolarized not depolarized in dark due to sodium ions efflux.
2. Depolarisation of the bipolar cell of the retina by glutamate release by rods and cones.
3. The adaption according to the light is known as a light adaptation which takes place due to a large part of photochemical in both rods and cones which is reduced to retinal and opsins.
4. when the light reaction takes place retinal converted to opsin
Answer:
Body tube (Head): The body tube connects the eyepiece to the objective lenses. Arm: The arm connects the body tube to the base of the microscope. Coarse adjustment: Brings the specimen into general focus. Fine adjustment: Fine tunes the focus and increases the detail of the specimen
Explanation:
Random, changes in a organism dna, delete and add.
Answer:
The diameter of the xylem vessels should be small in order for the capillary action to take place.
Explanation:
The vessels through which water is transported to different parts of the plants and trees are the xylem. Water is transported in the trees through a mechanism named as capillary action. This mechanism can occur only if the diameter of the vessels are small.
The water molecules adhere to the walls of xylem and an upward force is generated. If the diameter of the vessels i.e xylem would be small then the surface tension between the xylem and water molecules would be enough to move the water in an upward direction.
