Chapter 1 Flashcards
Evolution
The process of change that has transformed life on Earth from its earliest beginnings to the diversity of organisms living today
Biology
The scientific study of life
Life (7)
Order Energy processing Growth and development Evolutionary adaptation Response to environment Regulation Reproduction
Five unifying themes of life
Organization Information Energy and matter Interactions Evolution
Levels of biological organization (12)
Biosphere > Ecosystem > Community > Population > Organism > Organ system > Organ > Tissue > Cell > Organelle > Molecule > Atom
The Biosphere
consists of all life on Earth and all the places where life exists
Ecosystem
consists of all the living things in a particular area, along with all the nonliving components of the environment with which life interacts, such as soil, water, atmospheric gases, and light
Community
The array of organisms inhabiting a particular ecosystem
Population
consists of all the individuals of a species living within the bounds of a specified area
Organism
Individual living thing
Organ system
A team of organs that cooperate in a larger function
Organ
A body part that carries out a particular function in the body
Tissue
A group of cells that work together, performing a
specialized function
Cell
Life’s fundamental unit of structure and function. The smallest unit of organization that can perform all activities required for life
Organelle
A functional component present in cells
Molecule
A chemical structure consisting of two or more atoms
Atom
The smallest unit of matter that still retains the properties of an element
Reductionism
reduces complex systems to simpler components that are more manageable to study
Emergent properties
New properties that emerge due to the arrangement and interactions of simpler parts
Systems biology
The exploration of a biological system by analyzing the interactions among its parts
Structure and Function
At each level of the biological hierarchy, structure is correlated to function
Two types of cells
Eukaryotic cells and prokaryotic cells
Eukaryotic cell
contains membrane-enclosed organelles (such as the nucleus)
Prokaryotic cell
lacks a nucleus or other membrane-enclosed organelles and are generally smaller than eukaryotic cells
Chromosome
is made out of DNA and contains genetic information
Gene
A section of the DNA of a chromosome. It is the unit of inheritance
DNA molecule
is made up of two long strands, arranged in a double helix. Each strand is made up of four nucleotides (A, T, C, and G)
Gene expression
The process, by which a gene directs the manufacture of a cellular product (translation and transcription)
Genome
The entire “library” of genetic instructions that an organism inherits
DNA replication
The process of copying a DNA molecule
Transcription
The process of copying DNA into mRNA
Translation
The process of creating a protein from mRNA
Genomics
The study of whole sets of genes
Proteome
The entire set of proteins expressed by a given cell or group of cells
Proteomics
the study of sets of proteins and their properties
Bioinformatics
The use of computational tools to store, organize, and analyze the huge volume of data that results from high-throughput methods
Producers
convert energy from sunlight to chemical energy
Consumers
feed on producers and other consumers
Energy flow and chemical cycling
energy flows one way “through” an ecosystem (usually entering as light and exiting as heat). In contrast, chemicals are recycled “within” an ecosystem
Feedback regulation
The output, or product, of a process regulates that very process
Negative feedback
The end product “slows down” its own production (Insulin production). The most common type of feedback.
Positive feedback
The end product “speeds up” its own production (Blood clotting)
Number of species
1.8 million identified and named to date. Estimates range from about 10 million to over 100 million
Taxonomy
The branch of biology that names and classifies species. The classification of organisms in an ordered system that indicates natural relationships
Domains (3)
The highest level of taxanomic classification. Domain Archaea and Bacteria(most diverse and numerous) are prokaryotes. Domain Eukarya are eukaryotes
Kingdoms of domain Eukarya
Plantae, Animalia and Fungi are multicellular. Protists (most diverse and numerous eukaryotes) are unicellular.
Distinguish between plants, animals and fungi
These three kingdoms are distinguished partly by their modes of nutrition. Plants produce their own food by photosynthesis, fungi absorb dissolved nutrients from their surroundings, and animals obtain food by eating other organisms (ingestion).
Unity in the Diversity of Life
As diverse as life is, it also displays remarkable unity. E.g. the similar skeletons of different vertebrate animals and the universal genetic language of DNA
Science
A way of knowing—an approach to understanding
the natural world
Inquiry
A search for information and explanations of natural phenomena
Scientific method (process)
Observation Hypothesis Prediction Experimentation Conclusion
Data
Recorded observations
Qualitative vs. quantitative data
Qualitative data are in the form of recorded descriptions. Quantitative data record numerical measurements.
Inductive reasoning
To derive generalizations from a large number of specific observations
Deductive reasoning
From general premises, we extrapolate to the specific results we should expect if the premises are true
Hypothesis
A tentative answer to a wellframed question—an explanation on trial.
A proposed explanation for a phenomenon
Experiment
A scientific test (of an hypothesis), carried out under controlled conditions
Variables
Factors that vary in an experiment
Controlled experiment
An experiment that is designed to compare an experimental group with a control group. Ideally,
the experimental and control groups are designed to
differ only in the one factor the experiment is testing
Independent variable
The factor manipulated by experimenters
Dependent variable
A factor that is measured in the experiment and dependent on the independent variable
Control group
A group used in an experiment to cancel out the effects of different variables not currently tested. If a difference in still observed between the groups, it must be due to the one variable that the control group differs.
Theory
An explanation that is very broad in scope, generates new hypotheses and is supported by a large body of evidence
Natural selection
The evolutionary mechanism for descent with
modification.
Obervations:
1) Individuals in a population vary in their traits, many of which seem to be heritable. 2) A population can produce far more offspring than can survive on the limited resources; therefore, competition is inevitable. 3) Species are generally adapted to their environments
