WGU C190- Biology: Unit 1

Variable

- A factor that can change in an experiment

Pseudoscience

- A fake or false science that makes claims based on little or no scientific evidence. - The clearest line separating pseudoscience from real science is publication in peer-reviewed scientific journals.

Hypothesis

- A testable prediction, often implied by a theory

Community

- All the different populations that live and interact together in an area - Example: the forest with pine trees includes populations of flowers, mammals, birds, insects, fungi, and bacteria, all of which can interact.

Science

- An organized way of gathering and analyzing evidence about the natural world.

What are the 5 characteristics of life?

- Be made of materials organized in a hierarchical pattern. - Use energy and raw materials to survive. - Sense and respond to changing environments and maintain internal stability, or homeostasis. - Grow, develop, and reproduce. - Be part of a population that evolves.

Organs

- Collections of tissues that work together to carry out a common general function. - Organs are present not only in higher level animals but also in plants.

Atom

- Is the basic unit of matter. - The atom consists of a dense nucleus surrounded by electrons. - Atoms join together to form molecules.

Multicellular organisms

- Organisms composed of many cells (Ex. tissue, humans, fungi etc.)

Hershey-Chase Experiment (1952)

- The Hershey-Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material. While DNA had been known to biologists since 1869, many scientists still assumed at the time that proteins carried the information for inheritance because DNA appeared to be an inert molecule, and, since it is located in the nucleus, its role was considered to be phosphorus storage. In their experiments, Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. Hershey and Chase and subsequent discoveries all served to prove that DNA is the hereditary material.

Cell

- When macromolecules are used as building blocks to form a membrane-bound sphere, you have a cell, which is the fundamental unit of life. - While atoms and molecules are important parts of living things, they are not alive. The cell is the first level of the hierarchy in which life is present.

Biomes

- a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions. - Example: the desert biome can be found in many places, where rainfall is low and organisms are adapted to dry conditions.

Scientific Experiment

- a carefully organized procedure in which the scientist intervenes in a system to change something then observes the result of the change. - Example: scientist studying the mating behaviors of ladybugs might begin with detailed observations of ladybugs mating in their natural habitats. While this research may not be experimental, it is scientific: it involves careful and verifiable observation of the natural world. The same scientist might then treat some of the ladybugs with a hormone hypothesized to trigger mating and observe whether these ladybugs mated sooner or more often than untreated ones. This would qualify as an experiment because the scientist is now making a change in the system and observing the effects.

Molecule

- a chemical structure consisting of at least two atoms held together by a chemical bond

Organ System

- a higher level of organization that consists of functionally related organs. - Example: Mammals have many organ systems such as the circulatory system which transports blood through the body and includes organs such as the heart and blood vessels.

Heirarchy

- a system of organization in which each level is divided into smaller categories - Example: a population of ducks can be divided into the individual ducks. Each individual duck can then be divided into the different organ systems that make up that duck.

Scientific Inquiry

- an approach to asking and answering questions and is the best approach we have to understanding the natural world and predicting natural phenomena - Example: Prior to the 1700s, most medical practices were based on folk traditions or on ideas promoted by religious leaders. Some of these prescientific remedies worked, but the process for discovering new treatments was a slow and haphazard system of trial and error. Ineffective treatments were often accepted simply because there was no clear procedure for evaluating them. Today, with science-based medicine and public health practices, we have gained unprecedented control over threats to our health.

Macromolecules

- are biologically important molecules that are technically polymers. Polymers are made by combining smaller units called monomers, which are simpler macromolecules. - Example- DNA

Organelle

- compartments inside the cell that contain specific groups of macromolecules and carry out specific cellular functions - One of these organelles is the nucleus, which contains DNA inside the cell

Population

- consists of all the individuals of a species living within a specific area. - For example, a forest may include many pine trees. All those pine trees represent the population of pine trees in that forest

Ecosystem

- consists of all the living things in a particular area together with the abiotic, or nonliving, parts of that environment. - Example: The pine forest ecosystem includes not just plants, animals, and microbes but also rocks, water, temperature changes, air chemistry, and other abiotic factors that interact with living organisms in the area

Biosphere

- includes all habitable zones on the planet, including land, soil, and rocks to a great depth in the Earth's crust; water and ice; and the atmosphere to a great height.

Organisms

- individual living entities that survive and reproduce as a unit - For example, each tree in a forest is usually an individual organism.

Biotic

- matter that can be classified as living or having lived - Examples: dead humans inside a wooden coffin (both were alive at one point) - Bacteria is biotic as it meets all the characteristics of life.

Abiotic

- matter that can be classified as nonliving and never having been alive - Example: urea, the chemical component of urine, is abiotic because cells are the smallest unit that display the characteristics of life but the substances that make up cells, such as water, DNA, protein, etc, are not considered biotic. - Viruses are also abiotic since they cannot reproduce on their own and are not made of cells.

Microorganism

- organisms that consist of just one cell and include unicellular organisms such as bacteria and protists

Biology

- the scientific study of life and is the branch of science that studies living organisms and the way organisms interact with their environments.

Cell

- the smallest unit that displays all of the characteristics of life - because of this, living organisms are often identified based on whether or not they are made of cells