threadlike structures that assist in movement cylindrical tubular organelles that are involved in cell division tube-like structures that are the site of protein and lipid synthesis contain chlorophyll and are the site of photosynthesis the sites of cellular respiration and energy production digestion organelles that break down biomolecules into smaller molecules chloroplasts arrowBoth centrioles arrowBoth endoplasmic reticuli arrowBoth mitochondria arrowBoth cilia and flagella arrowBoth lysosomes

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

the fossil record provides evidence of a common ancestor to many species.

regents of the university of california v. bakke, 438 u.s. 265 (1978), was a landmark decision by the supreme court of the united states. it upheld affirmative action, allowing race to be one of several factors in college admission policy.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.