What is the difference between an exothermic and endothermic animal?
An example of an exothermic animal would be a lizard. An example of an endothermic animal would be a rabbit or even people. Exothermic animals rely on the ambient temperature (surrounding temperature) to increase or decrease their core body temperature whereas endothermic animals can maintain a core temperature on their own (humans maintain a core body temperature of 37 degrees Celsius.) Therefore, if a lizard is placed in a colder environment, its core body temperature will decrease. As for humans, we have ways of keeping our core body temperature at 37 degrees Celsius.
What is one of the themes of the book "Ender's Game" by Orson Scott Card?
Card insinuates in his book, "Ender's Game", the irrationality that overcomes humankind when they are challenged by the unknown. They could not communicate with the "buggers," and therefore, feared them. Fear can lead people to act in an extreme way which is shown in "Ender's Game" through the training of little kids for battle. Although the "buggers" were harmless and a kind race, fear led people to unnecessarily destroy them.
How is the horse different in her estrus compared to a cow?
The horse will ovulate from a specific area in the ovary called the ovulation fossa due to the reversal of the structure of the ovary. The cervix remains flaccid during the estrus whereas the cervix is more toned in the cow during estrus. The cervix in the horse consists of longitudinal folds whereas the cow has annular rings making it more difficult to artificially inseminate the cow.