Chapter 1 Biology
Define controlled experiment
Based on a comparison of a control group with an experimental group, which are identical except for one factor.
___________________________allows scientists to _____________ on the work of others.
Communication, build
define observation
Employs one or more of the five senses to perceive objects or events.
Define sexual repreoduction
Hereditary information from two parts of a single organism or from two organisms of the same species is combined, The joining produces a fertilized egg cell that contains hereditary information from both the female parent and the male parent, it begins a series of cell divisions and with each division each new cell receives a complete copy of the same hereditary information.
What is the DNA like in multicellular organisms?
Identical, each cell uses certain genes from the complete set, the other body parts ignore instructions not specific to themselves and use only genes appropriate to their functions.
A statement is testable when?
If evidence can be collected that does or does not support it.
Can a hypothesis be proved beyond doubt?
No, at any time, new data may indicate a previously accepted hypothesis does not hold true and they must refine revise and maybe discard original hypotheses as they uncover new evidence.
What are the steps of the scientific method in order
Observing, asking a question, collecting data, hypothesizing, experimenting, drawing conclusions
What is another difference between unicellular and multicellular organisms?
Unicellular always stay as one cell, but multicellular organisms start as one cell but then they contain many cells of all different types. The cells underwent differentiation.
Examples of analyzing data
Use stats to determine relationships between variables, compare data with those obtained in other studies and determine possible sources of experimental error.
define experimenting
What a hypothesis is carried out by. Process of testing a hypothesis or prediction by gathering data under controlled conditions
Cause and effect relationships can never be _______________ in a scientific ________________. Rather, evidence must be _______________ in every step.
assumed, investigation, accumulated
Scientists sometimes use models to help generate new _________________ or ______________________.
hypotheses or predictions
Define multicellular organisms
organisms composed of more than one cell
Define unicellular
organisms composed of only one cell
Define autotroph.
organisms that obtain their energy by making their own food, like plants. Using energy they trap from the sun, some autotrophs convert water and CO2 into sugars and starches which are used to meet energy needs. Other autotrophs use different processes to get energy
Living things have highly _____________________ structures that must be maintained in their orderly state by a constant supply of _________________.
organized, energy
What do scientists do with their findings?
they share them in scientific journals or share them at scientific meetings. The work of every scientist is subject to examination and verification by other scientists.
Define compound light microscope
(LM) magnifies up to 2000 times,Beam of light passes through lens
Describe cells : a feature of living things
-All living things are made of them - In multicellular organisms some are specialized. -Large multicellular organisms have many cells and smaller organisms have less.
Describe homeostatis : a feature of living things
-All living things maintain stable internal conditions. -Cell controls water content by taking in or releasing water -Multicellular organisms have more than one system for maintaining important aspects of their internal environment.
Describe reproduction : a feature of living things
-All species can do it -Not essential to life of one organism but essential for continuation of a species -Many species combine genetic info of individual members to produce offspring not identical to their parents
Describe energy use : a feature of living things
-Metabolism (sum of all the chemical processes that occur in a living thing) -Require energy to maintain molecular and cellular organization as well as grow and reproduce -Autotrophic organisms use energy they generate from photosynthesis for growth, maintenance, and reproduction
Describe organization : a feature of living things
-Organized at molecular and cellular levels -Take in substances from environment and organize them in complex ways -Specific cell structures carry out particular functions -Cells and groups of cells are organized by function
Six major themes of biology
-cell structure and function -stability and homeostasis -Reproduction and inheritance -Evolution -Interdependence of organisms -Matter, energy and organization
Describe growth : a feature of living things
-nonliving things grow by accumulating more of what theyre made of -living thing grow through cell division and enlargement -Unicellular: cell division results in more organisms -Multicellular: Cell division and cell enlargement together result in growth
Define electron microscope
A beam of electrons- rather than light- produces an enlarged image of the specimen. they are much stronger than light microscopes
Define theory and explain what it occurs after
A broad an comprehensive statement of what is thought to be true. Formed after many related hypotheses have been tested and supported with much experimental evidence, few true theories are made in science compared to the large amount of work performed
Define inference
A conclusion made on the basis of facts or premises rather than on direct observations.
How might the scientific method be used for problem solving?
A field biologist wishing to research animal sources of Ebola in the rain forest may combine observing, hypothesizing, sampling, organizing data, and analyzing data.
Define gene
A short segment of DNA that contains the instructions for the development of a single trait of an organism
What was the first organism to arise on Earth? When did it arise?
A single cell, 3.5 billion years ago. For millions of years, there were only single celled organisms.
Define prediction
A statement made in advance that states the results that will be obtained from testing a hypothesis. Takes the form of an if-then statement. It logically follows from the hypothesis and is used to test the hypothesis
Define evolution
A study that helps us understand how many kinds of organisms have lived on Earth and explains how organisms alive today relate to past organisms. It helps us understand why organisms look and behave they way they do and provides a basis for exploring the relationships among different groups of living organisms.
Define hypothesis
An explanation for what has been seen and recorded and a statement that explains observations and can be tested.
Define microscope
An instrument that produces an enlarged image of an object
Define data
Any and all information that scientists gather in trying to answer their questions.
How are cells similar and how are they organized?
Cells are surrounded by a membrane and have genetic information to make new cell parts and new cells from the molecules that the cell takes in. They contain special structures that carry out the cell's life processes.
Define differentiation
Cells becoming different from one another as they multiply and follow the various roles supplied for them by their genetic instructions.
Define evolve
Change, over generations
What is natural selection driven by?
Competition driven by resources needed for survival, like food. Some individuals have traits that help them to survive and reproduce and they tend to pass these traits on.
What is broken down into living things and what are living things set apart by?
Complex chemicals which are reassembled into chemicals and structures needed by the organism, their complexity
What are inferences drawn from?
Data gathered from a field study or experiment, considered together with previous knowledge. It is NOT testable
What must occur after a scientist has collected and organized data? What is analyzing data involve?
Data must be analyzed; Process of determining whether data is reliable or supports or does not support a hypothesis or prediction
What is quantitative data? Example.
Data that can be measured in numbers, dimensions of an object, number of objects in a group, duration of an event, or other characteristics in precise units
Define DNA
Deoxyribonucleic acid, a large molecule. It is enclosed in a membrane in some unicellular organisms, and in a loop for other unicellular organisms.
Define dependent variable
Driven by results from the independent variable. it is what is being measured.
define ecosystem
Environmental community
What occurs in asexual development?
Hereditary information from different organisms is not combined, one cell gives rise to two cells. Each of the two cells contains an identical copy of the hereditary information from the original bacterium.
What is the final steps of most investigations? Define it.
Model, Essentially an explanation of the data, and involves constructing a representation of an object, system, or process that helps show relationships among data.
What is scientific understanding of the natural world based on? It is the ______________ of something unusual or unexplained that raised the first __________________ in a scientific observation.
Observation, observation, questions
Define reproduction
Organisms producing two organisms like themselves, organisms transmit hereditary information through hereditary information
Define heterotroph
Organisms that must take in food to meet their energy need, include all animals and fungi as well as many unicellular organisms and a few plants. They must consume autotrophs or other heterotrophs.
What does organizing data involve? Why is it important?
Placing observations and measurements in some kind of logical order, like a graph, chart, table, or map. It is important because data is of little use unless it is organized.
Describe photosynthesis
Plants and some types of unicellular organisms capture the energy from the sun and change it into a form of energy that can be used by living things
Define derived units
Produced by the mathematical relationship between two base units or between 2 derived units
What occurs in the observation stage? Example.
Scientists take notice of what they want to study or notice an unusual circumstance. An observation of the new outbreak of a disease such as Ebola in Zaire.
Define base units
Seven fundamental units in SI: length, mass, time, electric current, thermodynamic temperature, amount of substance, luminous intensity
Explain the scanning electron microscope (SEM)
Striking 3D images. Specimens are not spliced for viewing instead they are sprayed with a metal coating, beam of electrons passes over surface and causes metal to emit shower of electron which is projected onto photographic plate or fluorescent screen. 100,000 times, No living specimens
What do animal bodies have to maintain internal conditions?
Systems that maintain temperature, water content, and food intake, at stable levels
Define ecology
The branch of biology that studies the interactions of organisms with one another and with their environment. Scientists may study a certain species or just an ecosystem
Define cell division
The formation of two cells from an existing cell
Define natural selection
The most important driving force in evolution, organisms that have certain favorable traits are better able to successfully reproduce than organisms that lack these traits.
What is the lense in the eyepiece called?
The ocular lens
Describe development
The process by which an adult organism arises. Produced by repeated cell divisions and cell differentiation. Adult organisms are made of many cells
Define biology and explain what it includes
The science of life (the study of all living things). Includes study of microscopic structure of single cells, study of global interactions of millions of organisms, study of life history of individual organisms as well as history of all organisms.
Define homeostasis
The stable level of internal conditions, found in all living things, including single cells.
Define sampling and what must be done for it to be useful
The technique of using a sample, a small part, to represent an entire population. Large and random, so they should include as many subjects as possible and scientists must sample a cross section of the population so an accurate representation can be made.
Define independent variable
The variable that separates the control group from the experimental group. It also is what the dependent variable depends on.
Explain the transmission electron microscope (TEM)
Transmits a beam of electrons through a very thinly sliced specimen. Magnetic lenses enlarge the image and focus it down on a screen or photographic plate, 200,000 power, No living specimens
What effect do humans have on environments around the world?
Tropical rainforests; plant and animal species become extinct, thin topsoil layer becomes depleted of nutrients and hardened by he sun, makes land unsuitable for planting, oxygen produced by dense forest is lost, replaced by carbon dioxide, loss of this could affect all life on Earth.
The cell is the ____________________________. All organisms are ____________ and _________________ cells.
basic unit of life, made of, develop from
In real life situations, scientists combine some of the steps in ways that is ______________ suited to answer the questions that they ask.
best
What are the six characteristics of life?
cells, organization,energy use, homeostasis, growth, and reproduction
Many organisms have not been identified live in regions of the world that are _________________________________________.
difficult to explore, like dense tropical rain forests and deep ocean waters. Or they are so small that they escape detection.
What are most observations in science? What is an example of the opposite quality
direct, electricity is observed indirectly
The stability of the ______________ depends on the healthy functioning of __________________ in that environment.
environment, organisms
Define organism
living thing
4 important aspects of collecting data
observing, measuring, sampling, organizing data
All scientific investigations begin with one or more __________________. What is the most important question for a disease outbreak?
questions; What is the disease causing agent?
Living things, from single cells to entire large organisms, maintain ___________________________________.
very stable internal conditions
Models can be...
visual, verbal, or mathematical
