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What is the basic definition of Biology?

The study of living organisms and their environments


What are the basic characteristics shared by all living organisms?

1. They are organized
2. They acquire materials and energy
3. The are homeostatic
4. They respond to stimuli
5. They reproduce and grow
6. They have an evolutionary history


What is a cell?

The smallest structural and functional unit of an organism/all living thigns


How are cells formed?

Atoms join together to form the molecules that make up a cell


What does it mean to be single-celled?

An organism is made up of only one cell


What does it mean to be multicellular?

An organism is composed of many different types of cells


What is an atom?

Smallest unit of an element composed of electrons, protons, and neutrons


What is a molecule?

The union of two or more atoms of the same or different elements


What is tissue?

A group of cells with a common structure and function


What is an organ?

Composed of tissues functioning together for a specific task


What is an organ system?

Composed of several organs working together


What is an organism?

An individual; complex individuals contain organ systems


What is a population?

Organisms of the same species in a particular area


What is a community?

Interacting populations in a particular area


What is an ecosystem?

A community plus the physical environment


What is a biosphere?

Regions of the Earth's crust, waters, and atmosphere inhabited by living things


What are the levels of biological organization on Earth?

• Atom
• Molecule
• Cell
• Tissue
• Organ
• Organ System
• Organism
• Population
• Community
• Ecosystem
• Biosphere


How do humans and other animals acquire materials and energy?

By eating food


How does food provide energy?

Food provides nutrient molecules which are used as building blocks or for energy.
• Food energy maintains the organization of the cell and of the organism
• Nutrient molecules are broken down completely to provide the necessary energy to convert other nutrient molecules into the parts and products of cells


What is the ultimate source of energy for the majority of life on earth?

The Sun


How does the Sun provide energy?

Plants, algae, and some bacteria harvest the energy of the sun and convert it to chemical energy by a process called photosynthesis. Photosynthesis produces organic chemicals, such as sugars, that serve as the basis for the food chain.


On average, how many cells make up the human body?

More than 100 trillion


What is homeostasis?

The ability of a cell or an organism to maintain an internal environment that operates under specific condition. An example is the human body temperature.


How does an organism respond to stimuli?

Organisms respond to external stimuli by moving toward or away from it. Their bodies respond to internal stimuli by adjusting to compensate for the stimuli, such as overheating.


What does it mean to reproduce?

Reproduction occurs when organisms pass on their genetic information to the next generation


What is growth?

Growth is recognized by an increase in size and often the number of cells as part of the development of an organism


What is development?

In multicellular organisms, development indicates all the changes that occur from the time the egg is fertilized until death, including the repair of injuries.


What is DNA and what purpose does it serve?

Deoxyribonucleic acid; It contains the hereditary information that directs not only the structure of each cell but also its function. DNA is contained within genes.


What are genes?

Genes are short sequences of hereditary material that specify the instructions for a specific trait. Genes contain the information that makes up DNA.


How do genes contribute to human reproduction?

Genes from the father and mother are carried to the offspring by the sperm and egg. The genes direct the growth and development so that the organism eventually resembles the parents.


What are mutations?

Minor variations in genes, resulting in unintended changed to an organism. These changes may result in traits making the organism better or worse suited for its environment. Mutations are the basis for evolutionary change.


What is the basic definition of Evolution?

Evolution is the process by which a population changes over time.


What is adaptation where evolution is concerned?

Certain traits within the population of a species offer organisms who possess them advantages in obtaining materials and energy from their environment. This trait variation from the norm passed on from generation to generation represents an adaptation to one's environment.


What causes diversity in organisms?

Though all organisms originated from a single/group of cell(s), over time, diversity was introduced as different organisms adapted to their environments. In essence, diversity exists because organisms are adapted to different ways of life.


What is an allele of a gene?

One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome


What is gene expression?

It is related to the switching on and off of genes (see location 206)


What gene is responsible for the regulation of hemoglobin present in the body?



What are the three domains by which biologists classify all life?

1. Bacteria
2. Archaea
3. Eukarya

Bacteria and Archaea contain prokaryotes, one-celled organisms that lack a nucleus


What are the 4 kingdoms of the Eukayra domain?

1. Plants (Plantae)
2. Fungi
3. Animals (Animalia)
4. Protists (Protista)

Most animals are invertebrates, such as earthworms, insects, and mollusks.



Vertebrates with hair or fur and mammary glands


What is a vertebrate?

An animal that has a nerve cord protected by a vertebral column, such as fish, reptiles, amphibians, and birds.


To what animals are humans most closely related?

Apes; humans did not evolve from apes. Apes and humans share a common ape-like ancestor


How are humans distinguished from apes?

1. Highly developed brains
2. Completely upright posture
3. Creative language
4. Ability to use a wide variety of tools


What is culture?

Human activities and products passed on from one generation to the next outside of direct biological inheritance.


What is biodiversity?

The number of different species present in a given area. The biodiversity of Earth is estimated as high s 15 million species.


What is extinction?

The death of a species. It is estimated that we lose as many as 20,000 to 30,000 species per year due to human activity.


What is a basic definition of science?

A way of knowing about the natural world


What is the difference between objective and subjective?

• Objective observations are supported by factual information
• Subjective observations involve personal judgment


What are scientific theories?

Concepts that tell us about the order and the patterns within the natural world.


Steps in the Scientific Method

1. Observe
2. Hypothesis
3. Experiment/Observations
4. Conclusion
5. Scientific Theory


What bacteria is responsible for stomach ulcers?

Helicobacter pylori


Dr. Barry James Marshall

Responsible for discovering the cause of stomach ulcers


Robert Koch

A German microbiologist who helped verify the germ theory of disease and established the standard as to whether an organism causes a particular disease.


Koch's Postulates

• The suspected pathogen must be present in every case of the disease
• The pathogen must be isolated from the host and grown in a lab dish
• The disease must be reproduced when a pure culture of the pathogen is inoculated into a healthy susceptible host
• The same pathogen must be recovered again from the experimentally infected host


What is an experiment?

A series of procedures to test a hypothesis


What are experimental variables?

The elements being tested in an experiment. In the case of a drug study, the drug(s) and dosage(s) would be the variables.


What is a control group?

In an experiment, the control group is the group of specimens for which you withhold the testing variables.


What is a test group?

In an experiment, the test group is the group of specimens that received the variable(s) for observation of effects.


What is informed consent?

In an experiment, voluntary participation of the experiments test subjects with a full disclosure of the details of the research


What is a placebo?

A treatment that appears to be the same as that administered to the other group(s) in an experiment but contains no medicine


What is a double-blind study?

An experiment in which neither the subject nor the tester knows which group is receiving which treatment


What is anecdotal data?

Data which consists of testimonials by individuals rather than results form a controlled clinical study


What is a standard error?

In statistics, the standard error tells us how uncertain a particular value is. It tells us how far off an average can be.


What is the probability value (p)?

The percent probability that your results are due to chance. Scientists like to see a probability value of 5% or less.