8/6/2019 Biology Chapter 1 Outline

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Elaine Liu 9/8/19

Biology Chapter One Outline

y Biology: the scientific study of living things.y Life: an organized genetic unit capable of metabolism, reproduction, and evolution.y Metabolism: the total chemical activity of a living organism.y Chemical reactions result in the capture of matter and energy and its conversion to different forms.y Chemical reactions must be coordinated for an organism to function.y Homeostasis: the maintenance of a relatively stable internal condition (such as body temperature).y Biological Evolution: a change in the genetic composition of a population or organisms over time.y Adaptations: differences among living things that enable them to live in different kinds of environments and

adopt different lifestyles.

y Count George-Louis Leclerc de Buffon (1707-1788) wrote Natural History of Animals which contained a clearstatement on the possibility of evolution.

y Jean-Baptiste de Lamarck (1744-1829) suggested that a lineage of organisms could change gradually overtime.

y Charles Darwin and Alfred Russel Wallace proposed new theories for evolution based on three observations:1. The reproductive rates of all organisms, even slowly reproducing ones, are sufficiently high that

populations would quickly become enormous if death rates were not equally high.

2. Within each type or organism, there are differences among individuals.3. Offspring are similar to their parents because they inherit their parents features.

y Darwin drew the following conclusion: The differences among individuals influence how well thoseindividuals survive and reproduce. Any traits that increase the probability that their bearers will survive and

reproduce are passed on to their offspring and to their offsprings offspring.

y Natural Selection: differential survival and reproductive survival of individuals.y Chemical evolution led to the appearance of life.y 3.8 billion years ago: cells formed from interacting systems of moleculesy Photosynthesis: the ability to use sunlight to power metabolismy

Two key developments that allowed multicellular organisms to be possible were:

the cells ability to changeits structure and function to meet the challenges of a changing environment and the ability for cells to stick

together after division and act together in a coordinated fashion.

y Sexual Recombination: the combining of genes from two different cells in one cell.y Speciation Events: splits in populationsy Autotroph: self-feeder; converts light energy into chemical energy using photosynthesis.y Heterotroph: other-feeder; require a source of energy-rich molecules synthesized by other organisms.y Each species of an organism is identified by two Latinized names. The first name identifies the genus (a group

of species that share a recent common ancestor) and the second name is the species name.

y The hypothesis-prediction (H-P) approach consists of five steps:` 1. Making observations

2. Asking questions

3. Forming hypotheses4. Making predictions

5. Testing the predictions

y Hypotheses can be tested in two ways: in a controlled experiment or using the comparative method.y The advantage of a controlled experiment is that all factors other than the one hypothesized to be causing

the effect can be kept constant.

y The comparative method is based on making predictions about patterns that should exist in nature if thehypothesis is correct and then gathering data to determine if the patterns do exist.