Chapter 1: Evolution, the Themes of Biology, Scientific Inquiry, and Some Math Terms

Evolution

change over time; the process by which modern organisms have descended from ancient organisms

Biology

the scientific study of life

Properties of Life

order, evolutionary adaptation, response to the environment, regulation, energy processing, growth and development, reproduction.

Example of Growth and Development

the cycle of a blowfly (application: forensic science)

Example of Response to Environment

phototropism (stimulus: light, tropism: orientation towards light). also: Venus flytrap closing on a fly (stimulus: touch; response: activating feeding mechanism, or closing)

Example of Regulation or Homeostasis

insulin and blood glucose level maintenance (negative feedback mechanism)

Example of Order

human genetic makeup, or the structure of DNA

Emergent properties

new properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases.

System biology

the exploration of a biological system by analyzing the interactions among its parts

Eukaryotic cell

cell that has a nucleus and other membrane-bound organelles

Prokaryotic cell

a type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.

DNA (deoxyribonucleic acid)

a complex molecule containing the genetic information that makes up the chromosomes.

Genes

sequence of DNA that codes for a protein and thus determines a trait

Nucleotides

Building blocks of nucleic acids

Base pairing

Principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

Gene expression

Process by which a gene produces its product and the product carries out its function.

Genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

Genomics

the study of whole sets of genes and their interactions

Proteomics

the study of sets of proteins and their properties

Bioinformatics

the application of computational methods to the storage and analysis of biological data

Producers

organisms that make their own food, photosynthetic

Consumers

Organisms that feed on producers and other consumers.

Feedback regulation

the output or product of a process regulates that very process

Negative feedback

a mechanism of response in which a stimulus initiates reactions that reduce the stimulus

Positive feedback

mechanism of homeostasis feedback that tends to magnify a process or increase or speeds up its output

Three domains of life

Bacteria, Archaea, Eukarya

Domain Bacteria

contains prokaryotic cells that differ from Archaea because they have their own unique genetic, biochemical, and physiological characteristics.

Domain Archaea

contains prokaryotic cells that often live in extreme habitats and have unique genetic, biochemical, and physiological characteristics

Domain Eukarya

consisting of organisms with eukaryotic cells; includes protists, fungi, plants, and animals.

Natural selection

an evolutionary mechanism for descent with modification; when the environment "selects" for the propagation of certain traits among naturally occurring variant traits in the population

Adaptation

inherited characteristic that increases an organism's chance of survival

Inquiry

a search for information and explanations of natural phenomena

Hypothesis

a testable prediction

Null Hypothesis

States that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

Data

evidence; information gathered from observations

Qualitative

data in the form of recorded descriptions rather than numerical measurements.

Quantitative

data that is numbers based.

Inductive reasoning

collecting and analyzing observations can lead to important

conclusions based on a type of logic

Experiment

a set of controlled observations that test the hypothesis

Deductive reasoning

logic that flows in the opposite direction, from the general to the specific.

Control group

the group that does not receive the experimental treatment.

Experimental group

the group that is exposed to the treatment, that is, to one version of the independent variable.

Variables

factors that can change in an experiment

Controlled experiment

an experiment that is designed to compare an experimental group with a control group

Independent variable

the experimental factor that is manipulated; the variable whose effect is being studied.

Dependent variable

the measurable effect, outcome, or response in which the research is interested.

Theory

a system of ideas that explains many related observations and is supported by a large body of evidence acquired through scientific investigation

Model organism

a particular species chosen for research into broad biological principles because it is representative of a larger group and usually easy to grow in a lab.

Biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

Ecosystem

All the living things in a particular area, along with all the nonliving components of the environment with which life interacts.

Community

The array of organisms inhabiting a particular ecosystem.

Population

All the members of one species in a particular ecosystem.

Organelle

A functional component present in a cell.

Organelle is to cell as organ is to organ system.

Example: mitochondria

Taxonomic Levels of Organization

Domain - Kingdom - Phylum - Class - Order - Family - Genus - Species

Kingdoms

High-level classification of organisms distinguished partly by their modes of nutrition.

Mean

Average of a group of measurements

Median

The value that is in the middle of a group of measurements.

Range

The difference between the smallest and the largest measurements.

R = Max - Min

Deviation

Measures how the measurements vary from the mean (+ or -). In other words, what is the difference between an actual measurement and the mean, or average, of the sample?

Variance

Measures how much difference, or variation, there is between the values you have obtained. The smaller the variance, the closer the values will be to the mean.

Standard Deviation

Standard deviation gives you an idea of how widely spread your values are about the mean. Smaller = closer values to the average. (Picture a tall, thin, bell-shaped curve. Larger - wide bell curve.)