The mariana trench is the deepest part of the world's oceans. it is located in the western pacific ocean and reaches a depth of over 36,000 feet. it is the result of a tectonic boundary that involves two high-density plates colliding. which type of boundary is it?

What must be done to breed dogs for a partical trait

Match the reproductive structures based on their function and the system to which they belong. egg ovary sperm vas deferens vagina fallopian tube testis urethra

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.