Which of these is mechanical isolation prezygotic barrier[a]A) two species live in different habitatsB) two species mate at different timesC) two species share courtship activitiesD) two snails have shells that spiral in different directions

To celebrate their 30th birthday, brothers Mario and Luigi of the Nintendo Mario video game franchise wish to study the distribution of heights of their enemies the Koopa Troopas. Koopa Troopas have normally distributed heights with mean 10 inches and standard deviation 2 inches. What is the probability that a randomly chosen Koopa Troopa is taller than the 25th percentile and shorter than the 75th percentile?  

Assume that the average price of a new house is $150,000, the standard deviation of prices is $10,000, and the variable price of a new house is normally distributed. If a new house is randomly selected, we can say: 

Probability considers information from a random sample

The enthalpy of reaction describes the relationship between the amount of reactant that undergoes reaction and the amount of ___________ produced.

MATCHING EXERCISE: Atoms and Elements

The explanation as to why 98.6% of DNA sequences in humans genes correspond to genes in chimpanzees. A) humans and chimpanzees share a relatively recent common ancestor.B) humans evolved from chimpanzees.C) chimpanzees evolved from humans.D) convergent evolution led to the DNA similarities.

Burning fossil fuels releases oxides and sulfur, ultimately these [a]A) can cause fish killsB) can cause acid rainC) can directly damage plants by leaching nutrientsD) can cause calcium deficienciesE) can cause any of these   

How did altruism arise through natural selection? [a]A) The altruist increases the likelihood that some of its genes will be passed on to the next generation.B) The altruist is appreciated by other members of the population because its survivability has been enhanced by virtue of its risky behavior.C) Animals that perform altruistic acts are allowed by their population to breed more, thereby passing on their behavior genes to future generations.D) Altruistic behaviors lower stress in populations, which increases the survivability of all the members of the population.

MATCHING EXERCISE – Chemical Bonding