Themes in the Life Sciences PDF

Themes in the Life Sciences Rice University. (2018). Biology for AP Courses. OpenStax. Rice University. Urry, Lisa; Cain, Michael; Wasserman, Steven; Minorsky, Peter; Orr, Rebecca; & Campbell, Neil. (2021). Campbell Biology. 12th Ed. Pearson. Science Science refers to...

Themes in the Life Sciences Rice University. (2018). Biology for AP Courses. OpenStax. Rice University. Urry, Lisa; Cain, Michael; Wasserman, Steven; Minorsky, Peter; Orr, Rebecca; & Campbell, Neil. (2021). Campbell Biology. 12th Ed. Pearson. Science Science refers to an organized body of knowledge. Science Biology is the scientific study of life. Its etymology derives from the Greek words “bios”, meaning life, and “logos”, meaning reason, thought, or principle. Hallmarks of Life Living organisms: have organization are composed of cells utilize energy react to stimuli grow and develop reproduce adapt as individuals and evolve as a species transmit and inherit traits through DNA and genes Hallmark 1: Organization Living organisms display systematic and highly structured levels of organization. At each level, characteristics called emergent properties can be observed. Hallmark 2: Cells Living organisms are composed of at least one cell. Organisms with a single cell are called unicellular. Organisms composed of multiple cells are called multicellular. Hallmark 2: Cells Cell is a term first coined by Robert Hooke in the manuscript, Micrographia. Our knowledge of cells is consolidated in the Cell Theory, a central tenet in biology, which is summarized as follows: The cell is the basic unit of life. All organisms have at least one cell. All cells arise from pre-existing cells. Hallmark 2: Cells The characteristics of cells, along with the structure of living organisms and their DNA, inform the classification of organisms into either three domains or five kingdoms. Hallmark 3: Energy Living organisms utilize energy. The entirety of processes that organisms go through to obtain and utilize energy is called metabolism. Organisms that are capable of producing their own food are called producers. Organisms that need to obtain food from other organic sources are called consumers. Learning prompt Which among the following is categorized as a life science? A. petrology, the study of rocks and minerals B. organic chemistry, the study of organic compounds and substances C. geology, the study of the solid component of the earth D. ecology, the study of how living organisms interact with the environment Learning prompt An organism is described as being a unicellular producer. This means that the organism: A. is composed of a single cell and obtains its nutrition from other organic matter B. is composed of a single cell and can manufacture its own food C. is composed of multiple cells and obtains its nutrition from other organic matter D. is composed of multiple cells and can manufacture its own food Hallmark 4: Reactivity Living organisms react to internal and external stimuli. This is known as reactivity or irritability. Organisms react to maintain an optimal state of functioning called homeostasis. Consider: do you know your baseline heart and breathing rates? What happens to your heart and breathing rates after doing a light exercise? Hallmark 5: Growth and Development Living organisms grow and develop. Hallmark 5: Growth and Development Growth refers to an increase in the number of cells. Development refers to an increase in an organism’s capacity. It can accomplish increasingly complex tasks as it develops. Hallmark 6: Reproduction Living organisms reproduce via sexual and asexual means. Sexual reproduction involves sex cells called gametes from two organisms of the same species. Asexual reproduction does not require sex cells and can be achieved by a single organism. Learning prompt Which scenario exemplifies development? A. the circumference of a tree trunk widens B. a corn seedling attains a taller height C. a hibiscus plant has begun to produce flowers D. the roots of a cactus reach deeper into the soil Learning prompt Snails are hermaphroditic, meaning they contain both male and female reproductive parts. When two snails meet, they exchange sperm to fertilize the other’s ova. Each snail then lays eggs that hatch into baby snails. What mode of reproduction is described? A. sexual B. asexual Hallmark 7: Adaptation and Evolution Living organisms adapt to their environment: they react and change to better match their environment and living conditions. Over time, these adaptations accumulate enough to alter the species. Thus, living organisms evolve. The Theory of Evolution is a central tenet in biology. Hallmark 7: Adaptation and Evolution Hallmark 8: Genetics and Inheritance Living organisms have DNA, whose unit called genes contain information about structure, characteristics, and behaviors. Traits can be passed on from parent to offspring in a process called inheritance or heredity. Learning prompt Which among the following are central theories in the life sciences? A. Theory of Relativity; Theory of Thermodynamics B. Classical Mechanics; Law of Universal Gravitation C. Cell Theory; Theory of Evolution D. Grand Unification Theory; Theory of Everything