A View of Life: Chapter 1

Biology

The scientific study of life

Organization of living things

Atom, molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere

Cell

The structural and functional unit of all living things (composed of many molecules working together)

Unicellular

An organism made of a single cell

Multicellular

An organism containing more than one cell

Emergent properties

A function or trait that appears as biological complexity increases (ex. a heart pumping is an emergent property of many cells interacting with one another)

Energy

Capacity to do work

Metabolism

All of the chemical reactions that occur in a cell (occurs when cells use nutrient molecules to make their parts + products)

Ultimate source of energy for all life on Earth

Sun

Photosynthesis

Process that turns solar energy into chemical energy of organic nutrient molecules

Homeostasis

A state of biological balance (factors like temp and moisture must remain in tolerance range, can be unconsciously controlled

Reproduction

Production of offspring

Unicellular reproduction

Cell splits in two

Multicellular reproduction

Union of sperm and egg → many cell divisions → immature stage → development throughout life

Genes

Parts of DNA that contain specific information for how the organism is to be ordered (passed down on to next generation through random combos of sperm + egg)

Adaptations

Modifications that allow organisms to function be in a specific environment

Evolutionary tree

Traces the ancestry of life on Earth to a common ancestor: the first cell(s)

Taxonomy

Identifying and grouping organisms based on certain rules

Systematics

The study of evolutionary relationships between organisms

Levels of classification (most to least inclusive)

Domain → kingdom → phylum → class → order → family → genus → species

Bacteria, eukarya, archea

3 domains

Prokaryotes

Organism that lacks membrane-bounded nucleus and membrane organelles (don't have a nucleus)

Eukaryote

Organism with membrane-bounded nucleus and membrane organelles

Protist

Single cell, eukaryotic organisms that are not a plant, fungus, or animal

Plants

Multicellular photosynthetic organisms

Fungi

Molds and mushrooms that help decompose dead organisms

Animals

Multicellular organisms that ingest and process food

Binomial nomenclature

The two-part scientific name assigned to each living thing (first word is genus, second word is species

Natural selction

A process where a species environment determines which traits improve fitness, passing them to the next generation

What fuels natural selection?

Mutations

Extinction

Death of a species or larger classification

Biosphere

Zone of air, land and water at surface of Earth where all life exists

Population

All members of a species living in the same area at the same time

Community

Multiple populations of species living in the same area

Biodiversity

Total number, relative abundance of species, genetic diversity, different ecosystems where species live

Scientific method

A series of steps that is widely used in gaining new knowledge that is widely accepted among scientists

Phenomenon

Observable natural event or fact

Observation

A formal way of seeing what happens (first part of scientific method)

Hypothesis

An informed statement that can be tested through science (second part of scientific method)

Inductive reasoning

Using creative thinking to combine facts into a cohesive whole

Experiment

A series of procedures done to test a hypothesis

Deductive reasoning

"If, … then…" logic used to determine how to test a hypothesis

Prediction

An expected outcome based on knowledge of the factors in an experiment

Experimental variable

The variable that is being examined (type of independent variable)

Control group

Group that is not exposed to the variable being tested

Purpose of a control group

Provides info on what effect the independent variable had on the results

Model

A representation of an actual object

Purpose of a model

It is used instead of an actual object because using the real object may be impossible, too expensive, or morally questionable

Data

The results of an experiment

observable, objective, proven

Data must be and . It must be able to be _

Standard deviation

A measure of how much the data in an experiment varies

Conclusion

Explanation of whether hypothesis is supported or not, fourth part of the scientific method

Scientific theory

A concept that joins together well-supported and related hypotheses, final step to the scientific method

Principle

Theory that is generally accepted by an overwhelming number of scientists

Law

Principle; describes the basic functions of the world

Responding variable

Result of change that occurs due to the experimental variable; type of dependent variable

Homologous

A structure that is similar in different types of organisms because they descended from a common ancestor

Lipids

Organic molecules that can’t dissolve in water, store energy long-term, build cell membranes, send signals

Carbohydrates

Organic molecules, primary energy source of living organisms, provide quick energy and store energy

Nucleic acids

DNA and RNA, store and transmit genetic information (tells our parents body how to work), guide the building of proteins

DNA VS RNA

DNA stores information, RNA tells the body what to do with it

Proteins

Chains of amino acids, do most of the work in cells, build structures, carry molecules, speed up chemical reactions as enzymes