A scientist wishes to determine how effective a vaccine is in protecting rats against a contagious disease. Which experimental procedure should the scientist use to determine the vaccines effectiveness?

Name three places on Earth where acid rain occurs and explain why it has developed in these locations.

Which statement about relative potential energy of electrons is correct? A. An electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 2 s orbital of the second electron shell. B.

Which is a characteristic of animals that are in the same food web?

You are an ecologist studying a newly discovered animal. you find that it reproduces quickly and has many offspring each time it reproduces. what type of organism is? an r-strategist logistical a k-strategist density dependent

Can someone explain to me why birds have wings in two paragraphs?

Explain the role of enzymes and how they affect the chemical reactions of living things

Many arthropods young do not look like adults and do not eat the same food as adults. how would this be an advantage in an environment where food is scarce

Mammals first appeared during the Cenozoic Era. true or false

Which organism is likely to live on the stump of a dead tree in a cool, moist, shady forest? A) beaver B) cactus C) mushroom D) rabbit

Independent assortment of chromosomes is a result of A) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. B) the random nature of the fertilization of ova by sperm.