A membrane that only "lets" certain molecules in while keeping other molecules out is ___ ___.

What should students always wear in the science laboratory?

Bacterial genomes choose one: a. are several circular chromosomes. b. depend on the species. c. are several linear chromosomes. d. are a single circular chromosome.

The segment of the small intestine that connects to the cecum a. large intestine b. jejunum c. duodenum d. stomach e. ileum

The resources that are provided by earth are known as resources

Which part of a leaf contains the most chloroplasts?

Which water-soluble vitamin plays an important role in the formation of collagen? A. vitamin C B. thiamin C. folate D. biotin

What is the theory on how cells came to have mitochondria.

Which of the following lists fits the order of these three descriptions: Age of Mammals, Age of Dinosaurs, and longest geologic time period. Choose one: A. Mesozoic, Cenozoic, Paleozoic B. Cenozoic, Mesozoic, Precambrian C.

The hypothalamus gland is important in many feedback loops. Which of the following systems does the hypothalamus work in? Check all that apply. A. endocrine B. nervous C. integumentary D. circulatory

Which scientist is matched with his contribution to evolutionary theory? Jean-Baptiste Lamarck-population growth Charles Darwin-inheritance of acquired traits Thomas Malthus-relationship of all living things Erasmus Darwin-competition and sexual