Answer/Explanation:
Types of reproductive isolation include: temporal, ecological, mechanical, and behavioural.
A snail with a flat disc-like shell will not be able to mate with a snail having a conical shell - this is an example of mechanical isolation, where the animals are physically unable to mate due to incompatible body shapes and sizes.
The reproductive organs of male bush babies do not match with the reproductive organs of females of other bush baby species. - this is another example of mechanical isolation, as the sexual organs will physically not allow reproduction between these species
The mating call of a cricket is not recognized by a cricket of other species - this is an example of behavioural isolation, which results from incompatible mating rituals. I.e. the animals do not respond to each others mating behaviours
The signals sent by a male firefly are not recognized by the female firefly of other species. - this is also an example of behavioural isolation.
Temporal isolation is where species cannot interact because they do not have the same mating seasons or are not active at the same type of day. ?Ecological isolation occurs when two species do not come into physical contact to one another because they access different areas of the habitat. E.g. mating zones, food sources or nesting sites.
Answer:
Unlike typical mammalian red blood cells, those from amphibians, such as frogs, contain a DNA-bearing nucleus that is visible in the center of the cell. The circulatory system of amphibians is rather unusual, their hearts having three chambers, two atria, and a single ventricle.
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The design of the amphibian circulatory system is curious because blood accumulates oxygen in the lungs and is then returned to the heart before being pumped into the rest of the circulatory system. Therefore, a mixing between oxygenated and deoxygenated blood occurs as blood returning to the heart from the lungs is mixed with incoming blood from the body. Frogs handle this situation by having a very slow metabolism and by absorbing some oxygen through their skin. In addition, the ventricle does have some directional control over the distribution of the blood.
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The presence of a nucleus in amphibian red blood cells allows researchers easy access to large quantities of amphibian DNA. Frog blood has both a solid and a liquid portion. The liquid plasma carries solid elements such as red and white blood cells. Blood can be collected from frogs and the red blood cells isolated by centrifugation. After removal of the residual plasma, purified cells can be treated with specific enzymes and detergents to digest the cellular envelope and release DNA from its protein complex. The DNA is then useful for scientific studies and experiments.
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Explanation:
