Introduction to Biology

All areas on, within, and around the planet Earth that are capable of supporting life. the highest level of organization in living systems is the biosphere, which is the collection of all ecosystems on Earth. The biosphere includes all habitable zones on the planet, including land, soil, and rocks to a great depth in the Earth's crust; water and ice; and the atmosphere to a great height.

Biosphere

An adjective that describes living organisms or their remains. Common characteristics of biotic (living) things are that they use energy and raw materials to grow, sense and respond to changing environments; they reproduce; and they consist of one or more cells.

Biotic

The smallest fundamental unit of structure and function in life. Cells are fluid-filled spaces bound by a membrane. When first formed, all cells include DNA and other macromolecules and are organized to grow, reproduce, and respond to changes in the external environment.

Cell

The study of matter and its structure, properties, and reactions. Understanding the basic principles of chemistry is vitally important in studying biology, as many biological interactions involve chemistry.

Chemistry

All of the populations interacting with each other within a specified area.

Community

Growth is just an increase in size. In development, structure and function change in an orderly way as an organism passes through its life cycle. An individual's pattern of development is partly determined by genetic instructions. DNA, the molecule of inheritance, encodes proteins and other molecules that build cells and make them work. You can think of genes as "recipes" for proteins. Each cell has a huge library of thousands of recipes in its DNAYour brain cells depend on freshly oxygenated blood flow, so if your lungs or heart stop functioning, your brain cells will die within several minutes. On the other hand, your lungs and heart work partly under the control of signals from your brain. You cannot digest food properly or make certain vitamins without help from bacteria in your gut, and these in turn depend on your body as a warm, nutrient-rich place to grow. Whatever example you came up with should have this sense of a two-way interaction: the cells are mutually dependent on one another. This is the core of the "interdependence" concept.

Describe an example of interdependence among cells within your body.

Change in structure and function that occurs in an orderly way as an organism passes through its life cycle.

Development

All the living things in a particular area together with the abiotic (nonliving) materials and conditions in that area. An ecosystem consists of all the living things in a particular area together with the abiotic, or nonliving, parts of that environment. The pine forest ecosystem includes not just plants, animals, and microbes but also rocks, water, temperature changes, air chemistry, and other abiotic factors that interact with living organisms in the area.

Ecosystem

Characteristics of a system that do not appear in any one of its component parts alone, but that appear when all parts are combined. As we ascend through this hierarchy to more and more complex levels, emergent properties appear. These are characteristics of a system that are not present in any of its component parts. Take, for example, an automobile. The separated parts of the automobile amount to a heap of junk. Only when properly assembled, with gas, the right key, and a human driver, does the car fulfill its function, which is to transport us from place to place. Life is an emergent property, and one that appears at the cellular level of organization. Molecules are not alive, but they are the components of life.

Emergent Properties

The capacity to do work or to make a change in the location, temperature, or structure of matter.

Energy

can be defined as the capacity to do work or to make a change in the location, temperature, or structure of matter. Energy does not have mass and it does not take up space, but it can be measured in terms of what it does. Energy comes in many forms, including heat, chemical potential energy, kinetic energy of motion, and light. Energy is required for all organisms to maintain homeostasis, grow, and reproduce. Energy comes in many forms, including heat, chemical potential energy, kinetic energy of motion, and light. Energy is required for all organisms to maintain homeostasis, grow, and reproduce.

Energy

Energy and matter move through living systems in different ways. Energy flows through living systems, changing forms as it goes. For example, the energy in sunlight is captured by green plants, which use this energy to build sugar molecules. The energy from the sun is now stored in the sugar and when an organism eats the sugar, the stored energy can be harvested and used to do work. The energy flows through the system; it is never recycled. Matter, on the other hand, cycles within living systems. For example, the atoms in the sugar molecule start out as nutrients, and will ultimately become waste. The waste might become nutrients for something else. Those same atoms will be used over and over again. Energy flow and nutrient cycling are themes in biology at every level.

Energy and Matter Behave Differently

A protein that speeds up the rate of chemical reactions that support life.

Enzyme

A scientific theory explaining how and why genetic changes occur in populations or higher-level groups over generations of time.

Evolution

a scientific theory that explains how and why life changes over time. Evolution provides the explanation for why all living organisms share profound similarities, and yet, the life forms on our planet are so incredibly diverse. The two fundamental tenets of evolution are shared ancestry and natural selection.

Evolution is

Increase in size of an organism. Biological growth, unlike the growth of a glacier or a mountain, is not merely an increase in size; it also involves the reorganization of materials into the unique structures of the organism.

Growth

Growth is just an increase in size. In development, structure and function change in an orderly way as an organism passes through its life cycle. An individual's pattern of development is partly determined by genetic instructions. DNA, the molecule of inheritance, encodes proteins and other molecules that build cells and make them work. You can think of genes as "recipes" for proteins. Each cell has a huge library of thousands of recipes in its DNA

Growth and DNA

The tendency of organisms and cells to maintain stable internal conditions. The term comes from the Greek words homeo (same, alike) and stasis (standing).

Homeostasis

We humans are dependent on algae and plants that produce food and oxygen gas, animals we harvest as food, and decomposers that get rid of wastes. They, in turn, may be dependent on us for cultivation (in the case of crop plants), protection, or a supply of food (the helpful bacteria in our sewage treatment plants would starve without us!). You probably came up with your own answer. Did the answer specifically describe how humans depend on the other species AND how the other species depends on us? If so, you've got a good grasp of interdependence.

Identify and briefly explain an example of interdependence between humans and other species in an ecosystem.

is a key form of energy. It is measured in units called calories.

In biology, chemical potential energy

highly organized and structured, following a hierarchy that can be examined on a scale from small to large.

Living things are

A large and complex molecule formed from combining smaller subunits, and consisting of many atoms. There are four main types of macromolecules that you will be learning about in this course: carbohydrates, nucleic acids, lipids, and proteins. Macromolecules are biologically important molecules, and they are technically polymers. When macromolecules are used as building blocks to form a membrane-bound sphere, you have a cell. Polymers are made by combining smaller units called monomers, which are simpler macromolecules. An example of a macromolecule is the genetic molecule deoxyribonucleic acid (DNA) that contains the instructions for the development of all living organisms.

Macromolecule

Module 3 /Energy and Matter traditionally defined as anything that has mass and takes up space. Matter is made of atoms. Matter is reused and recycled in living systems. To live and grow, organisms and cells must take in (or absorb, or ingest) certain forms of matter. Any matter an organism needs but cannot make for itself is considered a nutrient for that organism.

Matter is

substance that has mass and takes up space. All matter can be classified in one of two categories: biotic (living) or abiotic (nonliving).

Matter is any

A life form that cannot be seen with the naked eye; also called a microbe. Microorganisms include bacteria, many single-celled eukaryotes (plants, animals, fungi, and small creatures called protists), and even some multicellular life forms. Some organisms consist of just one cell and include unicellular organisms such as bacteria and protists. Single-celled life forms are typically referred to as microorganisms.

Microorganism

Two or more atoms held together by a chemical bond. A molecule is a chemical structure consisting of at least two atoms held together by a chemical bond. The diagram below illustrates a molecule of methane (CH4), in which four hydrogen (H) atoms are covalently bonded to one carbon (C) atom.

Molecule

Forms of matter that an organism requires and that the organism cannot make for itself. Nutrients must be taken in from the outside environment. Humans obtain nutrients from the food we eat and the water we drink. Plants take up nutrients through their roots (water and dissolved minerals) and from the air (carbon dioxide gas).

Nutrients

A collection of tissues grouped together based on a common general function. Some common organs in the human body are the heart, lungs, and kidneys.

Organ

Functionally-related organs that work together to carry out a function throughout an organism's body. Your body is made up of many organ systems, including the skeletal, digestive, and circulatory systems.

Organ System

A compartment inside the cells of eukaryotes that contain specific groups of macromolecules and carry out specific cellular functions.

Organelle

An organism is an individual living entity that survives and reproduces as a unit. Examples include a single bacterial cell, a plant grown from a single seed, or you—as an individual human being. Organs are collections of tissues that work together to carry out a common general function. Organs are present not only in higher level animals but also in plants. An organ system is a higher level of organization that consists of functionally related organs. Mammals have many organ systems. For example, the circulatory system transports blood through the body and includes organs such as the heart and blood vessels. Organisms are individual living entities that survive and reproduce as a unit. For example, each tree in a forest is usually an individual organism.

Organism

1. Be made of materials organized in a hierarchical pattern. 2. Use energy and raw materials to survive. 3. Sense and respond to changing environments and maintain internal stability, or homeostasis. 4. Grow, develop and reproduce with the help of DNA. 5. Evolve.

A living organism is something that displays all these qualities. To be considered alive, something must

An adjective that describes materials that are considered nonliving. Rocks, air, and ice are abiotic.

Abiotic

The basic unit of matter that cannot be further broken down without losing its unique properties. One atom consists of a dense nucleus surrounded by a cloud of electrons. Atoms join together to form molecules. The diagram below represents an atom of carbon.

Atom

The scientific study of life. Biology is a vast subject divided into many branches or subdivisions representing areas of specialization. Branches of biology include: anatomy, biochemistry, ecology, evolution, genetics, immunology, physiology, and many more.

Biology

the scientific study of life and is the branch of science that studies living organisms and the way organisms interact with their environments.

Biology is

All the individuals of a single species living within a specified area. population consists of all the individuals of a species living within a specific area. For example, a forest may include many pine trees. All those pine trees represent the population of pine trees in that forest. As you know, many different populations can live in any specific area. All of these populations can interact with each other in positive and negative ways, and together they form a community.

Population

Process by which an individual organism gives rise to offspring, passing on its genetic information to the next generation.

Reproduction

Process in which characteristics of a population change predictably over many generations. Selection takes forms such as natural selection (favors traits that aid in survival to reproductive age), sexual selection (favors traits that boost mating success), and artificial selection (favors traits that are chosen by human breeders).

Selection

the smallest unit that displays all of these characteristics. Because of this, living organisms are often identified based on whether or not they are made of cells. the cell, which is the fundamental unit of life. A cell is essentially a tiny droplet of water and other molecules enclosed by a fluid "skin" or membrane. The cell is the smallest and simplest entity that possesses all the characteristics of life. There are two main types of cells: prokaryotes and eukaryotes. The cells of prokaryotes are relatively small and simple; they do not have any clearly defined compartments inside of them.

The cell is

A group of similar cells carrying out the same detailed function within an organism. In the lung, for instance, the lining of airways comprises one type of tissue: a layer of similar cells that forms a sealed surface.

Tissue

are formed when many different kinds of cells work together to fulfill the same detailed function.

Tissues

When an organism or cell releases (or excretes) matter, the excreted matter is considered waste for that organism.

What is considered waste