Concepts in Biology

Enger Et Al.

Dr. Michael Gillespie

Doctor of Chiropractic

Beginner’s Mind“In the beginner’s mind there are many possibilities, but in the experts there are few. If your mind is empty, it is always ready for anything; it is open to everything.” – Shunryu Suzuki

BiologyBiology is the science that deals with life.Science is a process used to solve problems or develop an understanding of natural events.This process is known as the scientific method.

Scientific MethodThe scientific method is a way of gaining information (facts) about the world by forming possible solutions to questions.Rigorous testing is employed to determine if the proposed solutions are supported.

Basic Assumptions in Science

There are specific causes for events observed in the natural world.The causes for events in nature can be identified.There are general rules or patterns that describe what happens in nature.

Basic Assumptions in Science

Repeated events probably have the same cause.What one person observes can be observed by others.The same fundamental rules apply, regardless of when or where they occur.

Cause and EffectSome events are correlated (happen together).Some events have a cause and effect relationship (an event is a direct result result of a previous event).

Components of the Scientific Method

ObservationHypothesesOpenness to new information and ideasWillingness to submit ones ideas to the scrutiny of others

ObservationObservations are made using our senses or an extension of our senses.Observations are careful, thoughtful recognition of an event.

Questioning and Exploration

Optimal questions lend themselves to experimentation.Explore other sources of knowledge relevant to the question.

HypothesisA hypothesis is a statement that provides a possible answer to a question or an explanation for an observation that can be tested.

Characteristics of a Good Hypothesis

LogicalAccount for all relevant informationPredict future eventsTestableUse the simplest hypothesis with the fewest assumptions

Einstein“Make everything as simple as possible, but not simpler.”

Testing a HypothesisA good hypothesis is testable.It can be either supported or disproved.If a hypothesis cannot be disproved, confidence in it increases.New information can encourage scientists to reformulate an hypothesis.

Methods for Testing a Hypothesis

Collect relevant information.Make additional observations.Devise an experiment.

ExperimentAn experiment is a re-creation of an event or occurrence in a manner that allows the scientist to support or disprove a hypothesis.

VariablesVariables are individual factors that help determine the outcome of an event.

Controlled ExperimentA controlled experiment is one in which only one variable is present.Two groups:

Control group – no manipulation of the variable.Experimental group – a group in which one variable is manipulated.

VariablesIndependent variable – is manipulated in the experiment by the scientist.Dependent variable – will change as a result of manipulation of the independent variable.There should be only one independent variable in an experiment.Be careful not to introduce additional variables into the experiment.

Development of Theories and Laws

If new evidence consistently and repeatedly supports the original hypothesis and other related hypotheses, we begin to see patterns emerge.Scientific theories and laws come into existence.

Inductive ReasoningThe process of developing general principles from the examination of many specific facts is known as inductive reasoning or induction.

Deductive ReasoningThe process of using general principles to predict the specific facts of a situation is called deductive reasoning or deduction.

Scientific TheoryA theory is a widely accepted, plausible, general statement about fundamental concepts in science that explain why things happen.A theory is a very broad statement , which is the result of years of observation, questioning, experimentation, and data analysis.

Theory Vs. HypothesisA hypothesis provides a possible explanation for a specific question; whereas a theory is a broad concept that shapes how scientists look at the world and how they frame their hypotheses.

Scientific LawA scientific law is a uniform or constant fact of nature that describes what happens in nature.

Theory Vs. LawTheoryDescribes why things happenExamined repeatedlyIndependently verifiedExcellent predictors of how nature behaves

LawDescribes what happens in natureExamined repeatedlyIndependently verifiedExcellent predictors of how nature behaves

Theoretical And Applied Science

Theoretical science helps us understand the structure and function of things in nature.Applied science has practical value. It has applications that change the way we live.

Science And NonscienceThe difference between a scientist and a non-scientist is lies in the manner in which assumptions are tested.A scientist continually challenges and tests principles and assumptions to determine cause and effect relationships.

PseudosciencePseudoscience is a deceptive practice that uses the appearance or language of science to convince, confuse, or mislead people into thinking that something has scientific validity.

What Is Life?Living things have the ability to interact with their surroundings.Living things can manipulate energy and matter.Energy is the ability to do work.Matter is anything that has mass and takes up space.

Characteristics Of LifeMetabolic processes.Generative processes.Responsive processes.Control processes.Unique structural organization.

MetabolismMetabolism is the sum of all the chemical processes that occur in the body.

Catabolism – The breaking down of complex chemical substances into simpler ones.Anabolism – The building up of complex chemical substances from simpler ones.

Generative ProcessesGenerative processes are activities that result in an increase in the size of an organism (growth) or an increase in the number of individuals in a population (reproduction).

GrowthGrowth is an increase in body size that results from an increase in the size of existing cells, the number of cells, or both.A tissue can increase in size due to an increase in the amount of material between cells (i.e. bone tissue).

ReproductionReproduction is the formation of new cells for tissue growth, repair, or replacement.The formation of new cells for the production of a new individual organism (i.e. through fertilization of an ovum by a sperm cell).

Two Types Of Reproduction

Sexual reproduction – two individuals each contribute sex cells, which leads to the creation of a new, unique organism.Asexual reproduction – an organism makes identical copies of itself.

Responsive ProcessesResponsiveness is the body’s ability to detect and respond to changes in it’s internal and external environment.

Control ProcessesControl processes are mechanisms that ensure an organism will carry out all metabolic activities in the proper sequence (coordination) and at the proper rate (regulation).

Levels Of CoordinationCoordination occurs at the metabolic level. Chemical reactions are regulated in the human body by enzymes.Coordination also occurs at the organism level.

MovementMotion of the whole body.Motion of individual organs.Motion of single cells.Motion of structures inside cells.

DifferentiationDifferentiation is a process a cell undergoes to develop from an unspecialized to a specialized state.Each type of cell has a specialized state and function.Stem cells divide and give rise to progeny that undergo differentiation.

RegulationRegulation involves altering the rate of processes.The process of maintaining a constant internal environment is called homeostasis.

Unique Structural Organization

The unique structural organization of living things can be seen at the molecular, cellular, and organism levels.Cells are the fundamental structural units of all living things.An organism is any living thing that is capable of functioning independently.

Levels Of Body Organization

Chemical levelCellular levelTissue levelOrgan levelSystem levelOrganism

Chemical LevelAtoms – smallest units of matter that participate in chemical reactions.Molecules – two or more atoms joined together.

Cellular LevelMolecules combine to form cells.Cells are the basic structural and functional units of an organism.Cells are the smallest living units in the human body.Cells are made up of organelles.

TissuesTissues are groups of cells and the materials surrounding them that work together to perform a particular function.4 basic tissue types in the human body:

Epithelial tissue.Connective tissue.Muscle tissue.Nervous tissue.

OrgansOrgans are composed of two or more tissues that work together to perform specific functions.They usually have recognizable shapes.

System LevelA system consists of related organs that have a common function.Sometimes an organ is part of more than one system.There are eleven systems in the human body.

Organ SystemsIntegumentaryMuscularSkeletalNervousEndocrineLymphatic and immune

CardiovascularRespiratoryDigestiveUrinaryReproductive

Integumentary SystemComponents – skin, hair, nails, sweat glands, oil glands.Functions – protects the body; Helps regulate body temperature; Eliminates wastes; Makes vitamin D; Detects sensations such as touch, pain, warmth, and cold.

Muscular SystemComponents – muscles, tendons.Functions – produces body movements, such as walking; Stabilizes body position (posture); Generates heat.

Skeletal SystemComponents – bones, joints, associated cartilages.Functions – supports and protects the body; Aids body movements; Houses cells that produce blood cells; Stores minerals and lipids.

Nervous SystemComponents – brain, spinal cord, nerves, special sense organs (I.E. Eyes and ear).Functions – generates action potentials (nerve impulses) to regulate body activities; Detects changes in the body’s internal and external environments, interprets these changes, and responds causing muscular contractions or glandular secretions.

Endocrine SystemComponents – hormone producing glands and hormone producing cells.Functions – regulates body activities by releasing hormones (chemical messengers) transported in blood from an endocrine gland to a target organ.

Lymphatic and Immune System

Components – lymphatic fluid and vessels; Spleen, thymus, lymph nodes, tonsils.Functions – returns proteins and fluids to blood; Carries lipids from gastrointestinal tract to blood; Includes structures that generate lymphocytes (protect against disease-causing organisms).

Cardiovascular SystemComponents – blood, heart, and blood vessels.Functions – heart pumps blood through vessels; Blood carries oxygen and nutrients to cells and carbon dioxide and wastes away from cells; Regulates acid-base balance, temperature, and water content of body fluids; Components defend against disease.

Respiratory SystemComponents – lungs, air passageways such as the pharynx (throat), larynx (voice box), trachea (windpipe), and bronchial tubes.Functions – transfers oxygen from inhaled air to blood and carbon-dioxide from blood to exhaled air; Regulates acid-base balance, air flowing out through vocal cords produces sounds.

Digestive SystemComponents – mouth, esophagus, stomach, small and large intestines, and anus (organs of GI tract); Salivary glands, liver, gallbladder, pancreas (accessory organs).Functions – physical and chemical breakdown of food; Absorbs nutrients, eliminates solid wastes.

Urinary SystemComponents – kidneys, ureters, urinary bladder, urethra.Functions – produces, stores, and eliminates urine; Eliminates wastes; Regulates volume and chemical composition of blood; Maintains acid-base balance; Maintains mineral balance; Helps regulate production of red blood cells.

Reproductive SystemsComponents – gonads (testes in males, ovaries in females), associated organs (uterine tubes, uterus, and vagina in females and epididymis, ductus deferens, and penis in males).Functions – gonads produce gametes (sperm or oocytes); Gonads release hormones.

Further Levels Of Organization

Population – a group of individual organisms of a particular kind.Community – populations of different kinds of organisms that interact with one another in a particular place.Ecosystem – communities (groups of populations) that interact with the physical world in a particular place.Biosphere – the worldwide ecosystem.