Question: Q: What type of protein fibers in the cytoskeleton are the narrowest? Read this paragraph and choose the correct option from the provided answers: Microfilaments Of the three types of protein fibers in the cytoskeleton, microfilaments are the narrowest. They function in cellular movement, have a diameter of about 7 nm, and are made of two intertwined strands of a globular protein called actin (Figure 4.23). For this reason, microfilaments are also known as actin filaments. Choices: - macrophages - mitosis - capillaries - microfilaments A:
Answer: microfilaments

Question: Q: What umbrella term describes small structures that exist within cells and perform specialized functions? Read this paragraph and choose the correct option from the provided answers: To see an animation of this DNA molecule, click here (http://openstaxcollege. org/l/rotating_DNA2) . Some cells contain aggregates of macromolecules surrounded by membranes; these are called organelles. Organelles are small structures that exist within cells and perform specialized functions. All living things are made of cells; the cell itself is the smallest fundamental unit of structure and function in living organisms. (This requirement is why viruses are not considered living: they are not made of cells. To make new viruses, they have to invade and hijack a living cell; only then can they obtain the materials they need to reproduce. ) Some organisms consist of a single cell and others are multicellular. Cells are classified as prokaryotic or eukaryotic. Prokaryotes are single-celled organisms that lack organelles surrounded by a membrane and do not have nuclei surrounded by nuclear membranes; in contrast, the cells of eukaryotes do have membrane-bound organelles and nuclei. In most multicellular organisms, cells combine to make tissues, which are groups of similar cells carrying out the same function. Organs are collections of tissues grouped together based on a common function. Organs are present not only in animals but also in plants. An organ system is a higher level of organization that consists of functionally related organs. For example vertebrate animals have many organ systems, such as the circulatory system that transports blood throughout the body and to and from the lungs; it includes organs such as the heart and blood vessels. Organisms are individual living entities. For example, each tree in a forest is an organism. Single-celled prokaryotes and single-celled eukaryotes are also considered organisms and are typically referred to as microorganisms. Choices: - macromolecules - atoms - organisms - organelles A:
Answer: organelles

Question: Q: What are the three stages of water? Read this paragraph and choose the correct option from the provided answers: (A) Natalie Lucier; (B) Gareth Haywood; (C) Lynn Greyling. Ice, liquid, and water vapor are the three phases of water . (A) CC BY 2.0; (B) CC BY 2.0; (C) Public Domain. Choices: - ice, rock, sky - vapor, earth, internal - liquid, underground, frozen - ice, liquid, vapor A:
Answer:
ice, liquid, vapor