1.2 - Themes and Concepts of Biology

Viruses are not considered living because they ________. a. are not made of cells b. lack cell nuclei c. do not contain DNA or RNA d. cannot reproduce

A

The presence of a membrane-enclosed nucleus is a characteristic of ________. a. prokaryotic cells b eukaryotic cells c. living organisms d. bacteria

B

A group of individuals of the same species living in the same area is called a(n) ________. a. family b. community c. population d. ecosystem

C

The smallest unit of biological structure that meets the functional requirements of "living" is the ________. a. organ b. organelle c. cell d. macromolecule

C

Where in a phylogenetic tree would you expect to find the organism that had evolved most recently? a. at the base b. within the branches c. at the nodes d. at the branch tips

D

Which of the following sequences represents the hierarchy of biological organization from the most inclusive to the least complex level? a. organelle, tissue, biosphere, ecosystem, population b. organ, organism, tissue, organelle, molecule c. organism, community, biosphere, molecule, tissue, organ d. biosphere, ecosystem, community, population, organism

D

You go for a long walk on a hot day. Give an example of a way in which homeostasis keeps your body healthy.

During your walk, you may begin to perspire, which cools your body and helps your body to maintain a constant internal temperature. You might also become thirsty and pause long enough for a cool drink, which will help to restore the water lost during perspiration.

Select two items that biologists agree are necessary in order to consider an organism "alive." For each, give an example of a non-living object that otherwise fits the definition of "alive,"

Layers of sedimentary rock have order but are not alive. Technology is capable of regulation but is not, of itself, alive.

Using examples, explain how biology can be studied from a microscopic approach to a global approach.

Researchers can approach biology from the smallest to the largest, and everything in between. For instance, an ecologist may study a population of individuals, the population's community, the community's ecosystem, and the ecosystem's part in the biosphere. When studying an individual organism, a biologist could examine the cell and its organelles, the tissues that the cells make up, the organs and their respective organ systems, and the sum total—the organism itself.

Consider the levels of organization of the biological world, and place each of these items in order from smallest level of organization to most encompassing: skin cell, elephant, water molecule, planet Earth, tropical rainforest, hydrogen atom, wolf pack, liver.

Smallest level of organization to largest: hydrogen atom, water molecule, skin cell, liver, elephant, wolf pack, tropical rainforest, planet Earth