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Questions and Answers
What is the basic unit of life in all organisms?
What process explains how new organisms arise from older kinds?
Which of the following themes of biology addresses the internal balance of organisms?
What must multicellular organisms undergo as they develop?
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What is a characteristic of cells?
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What is the maximum magnification of a compound light microscope?
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Which of the following statements about electron microscopes is true?
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What term describes the clarity or detail of an image produced by a microscope?
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What must be done to specimens before using a compound light microscope?
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Which type of microscope produces a three-dimensional image?
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What is the main disadvantage of using transmission electron microscopes?
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Which lenses are part of a compound light microscope?
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Which measurement system is most widely used globally?
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What is the result of cell growth when a cell's surface area is insufficient for its volume?
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Which statement accurately defines development in biological terms?
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What is essential for the continuation of a species?
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How is evolution driven in organisms?
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What is the first step of the scientific method?
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Which best describes a hypothesis?
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What is a control group in a scientific experiment?
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What denotes the successful organization of data in scientific studies?
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What steps follow after collecting and analyzing data in scientific research?
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What distinguishes a scientific theory from a hypothesis?
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What is the primary component of genetic information in all cells?
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In sexual reproduction, what forms after fertilization occurs?
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What process do organisms undergo when they reproduce asexually?
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Natural selection primarily explains how which of the following occurs?
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Which term describes organisms that produce their own food using sunlight?
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What is a key characteristic of multicellular organisms in terms of cell organization?
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What is the ultimate source of all energy used by living organisms?
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How do heterotrophs obtain their energy?
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What does the term 'homeostasis' refer to in biological systems?
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Which process allows organisms to convert sunlight into energy?
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What is coevolution?
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In the context of evolution, the term 'survival of the fittest' refers to which concept?
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Which of the following best describes metabolism in living organisms?
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Study Notes
Biology - The Study of Life
- Life arose more than 3.5 billion years ago
- First organisms were single-celled
- Organisms changed over time, evolving
- New organisms arose from older kinds
- Millions of species exist today
- Organisms inhabit almost every region of Earth
Themes of Biology
- Cell structure and function
- Stability and homeostasis
- Reproduction and inheritance
- Evolution
- Interdependence of organisms
- Matter, energy and organization
### Cell Structure and Function
- Cell is the basic unit of life
- All organisms are made of and develop from cells
- Organisms are:
- Unicellular (one cell)
- Multicellular (many cells)
- Cells are different and undergo differentiation
- Cells are small and are highly organized
- Cells contain specialized structures (organelles) that carry out the cell's life functions
- Many different kinds of cells exist in multicellular organisms
- All cells are surrounded by a plasma membrane
- Cells contain a set of instructions called DNA (genetic information) which is passed on from parent to offspring
Stability and Homeostasis
- Organisms must maintain stable internal conditions - Homeostasis
- Internal conditions that must be maintained include:
- Temperature
- Water content
- Chemical content
Reproduction and Inheritance
- All organisms produce new organisms like themselves- REPRODUCE
- Organisms transmit hereditary information to their offspring - INHERITANCE
### DNA
- DNA is the genetic information found in all cells
- Deoxyribonucleic Acid
- DNA contains instructions for traits - GENES
- DNA also makes structures and chemical compounds necessary for life - PROTEINS
- DNA in every body cell (somatic) is exactly alike
Sexual Reproduction
- Hereditary information from two different organisms of the same species are combined
- Egg and sperm --> zygote (fertilized egg)
- Zygote contains hereditary information from both parents
Asexual Reproduction
- Hereditary information from one, usually unicellular organism, that divides.
- The resulting cells contain identical hereditary information
- Genetic information from a single parent.
Evolution
- Populations of organisms change (evolve) over generations.
- This explains how many different kinds of organisms came into existence - SPECIES
- It also explains how modern organisms are related to past organisms
- This explains why organisms look and behave the way they do
- It provides a basis for exploring the relationships among different groups of organisms
Natural Selection
- Natural selection is the driving force of evolution
- Organisms that have certain favorable traits are better able to successfully reproduce than organisms that lack these traits.
- Survival of organisms with favorable traits causes a gradual change in populations over many generations
- This is also called “Survival of the Fittest”
Interdependence of Organisms
- Organisms interact with one another and their environment - ECOLOGY
- Organisms depend on each other for food and resources -e.g. insects and flowers
- This relationship is called coevolution, where organisms have evolved together to depend on each other.
Matter and Energy and Organization
- Living things are highly organized
- They require a constant supply of energy to maintain their orderly state
Energy
- All energy comes from the Sun (directly or indirectly)
- Photosynthesis is the process by which some organisms capture the energy of the sun (solar) and transform it to energy (chemical) that can be used by living things
Autotrophs
- Organisms that make their own food are called autotrophs
- There are two types:
- Phototrophs
- Use solar energy (photosynthesis)
- Convert H2O and CO2 into sugar and oxygen
- Chemotrophs
- Use different chemical processes to get energy
- Phototrophs
Heterotrophs
- Organisms that must take in food to meet their energy needs are called heterotrophs
- These organisms include:
- Herbivores (eat plants)
- Carnivores (eat other animals)
- Omnivores (eat both plants and animals)
- They consume other organisms to get their energy needs
- Complex chemicals are broken down and reassembled into chemicals and structures needed by organisms
Characteristics of Life
- Cells
- Organization
- Energy Use
- Homeostasis
- Growth
- Development
- Reproduction
- Responsiveness
- Evolve
Cells
- All living things are composed of cells
- In multicellular organisms, many cells are specialized to perform specific functions
- Cells are always very small
Organization
- Organized at both the molecular and cellular levels
- They take in substances from the environment and organize them in complex ways
- Specific cell structures (organelles) carry out particular functions
- In multicellular organisms, cells and groups of cells (tissues) are organized by function
- Cells > tissues
- Tissues > organs
- Organs > systems
- Systems > ORGANISM
Energy Use
- Organisms use energy in a process called metabolism which is the sum of all chemical processes
- Organisms require energy to maintain their molecular and cellular organization, to grow and to reproduce
Homeostasis
- Organisms maintain stable internal conditions such as:
- Temperature
- pH
Growth
- Growth occurs as a result of cell division and cell enlargement
- Cell division is the formation of two cells from a preexisting cell
- New cells enlarge as they mature
- When a cell grows to a size where its surface area isn’t big enough for its volume, the cell divides
Development
- Development is the process by which an adult organism arises
- This is done through repeated cell divisions and cell differentiation
Reproduction
- All species have the ability to reproduce
- Not essential to survival of the individual
- But essential for continuation of a species
Responsiveness
- Respond to stimuli in the external environment
- Organisms detect and respond to changes in:
- Light
- Heat
- Sound
- Chemical and mechanical contact
- Organisms coordinate their responses
Evolve
- Organisms adapt to their environment through the process of evolution
- Favorable characteristics are selected for and passed on to offspring - Adaptations
- Driven by natural selection or “survival of the fittest”
Scientific Method
- Observation
- Asking a question
- Forming a hypothesis
- Experimenting
- Organizing data
- Analyzing data
- Conclusion
- Communication
Observation
- Employing your five senses to perceive objects or events
Asking a Question
- One or more questions are generated based on observations
Forming a Hypothesis
- A statement is testable if evidence can be collected that either does or doesn’t support it.
- Can never be proven beyond a reasonable doubt
- Often must be refined and revised or discarded
- It is a statement made in advance that states the results that will be obtained from testing the hypothesis
- Often written in the form of an “if, then” statement
Experimenting
- Testing a hypothesis or prediction gathering data under controlled conditions - a controlled experiment
- Based on a comparison of a control group with an experimental group
- Both groups are identical except for one factor (Independent Variable)
- Observations and measurements are taken for a particular factor (dependent variable) in both groups
Organizing Data
- Involves placing observations and measurements (data) in order
- Graphs, charts, tables, or maps
Analyzing Data
- Collected and organized data must be analyzed
- The process of determining whether data are reliable or whether they support or do not support a hypothesis
Conclusion
- Conclusions are made on the basis of facts, not observations
- Often drawn from data gathered from a study or experiment
- Should support the hypothesis
- Should be re-testable
Communication
- Scientists must share the results of their studies with other scientists (peers)
- Publish findings in journals
- Present their findings at scientific meetings
- Scientists must be unbiased
- Should not tamper with their data
- Only publish & report tested & proven ideas
- Sharing information is essential to the scientific process
- Subject to examination and verification by other scientists
- Allows scientists to build on the work of others
Theories
- Formed after many related hypotheses have been tested and supported with experimental evidence
- Broad and comprehensive statements of what is thought to be true
- Supported by considerable evidence
- Ties together related hypotheses
Laws
- A statement of fact that concisely explains an action or group of actions
- e.g. Law of Gravity
- Accepted to be true
- Universal
- May be expressed as a math equation
- e.g. E=mc2
Microscopes
- Microscopes produce an enlarged image of an object used to study organisms, cells and cell parts
- Increase in apparent size is called magnification
- The ability to show details clearly is called resolution
- Microscopes vary in both magnification and resolution
Compound Light Microscopes
- Specimen mounted on a glass slide
- Must be thinly sliced or very small
- Pair of lenses:
- Ocular lens (eyepiece)
- Objective lens (nosepiece)
- Can be used to study live specimens
- Magnification determined by multiplying the power of both lenses
- Eyepiece 10X times Objective power (20X, 40X…)
- Highest Maximum magnification is around 1000X
Electron Microscope
- The transmission EM (TEM)
- Uses beam of electrons to produce an enlarged image of very thinly sliced specimen on screen or photographic plate
- Image focused by magnetic lenses
- 200,000X magnification
- Cannot be used to view living specimens
- The Scanning EM (SEM)
- Produces 3-D images
- Specimens not sliced for viewing
- Surface sprayed with a fine metal coating
- Also uses an electron beam and fluorescent screen or photographic plates
- 100,000X magnification
- Cannot be used to view living specimens
Measurements
- We will be using SI units or the metric system when possible (the entire world uses the metric system except the United States)
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Description
This quiz explores fundamental concepts in biology, focusing on the origins of life, cellular structure, and the principles that govern living organisms. It covers themes such as evolution, reproduction, and the interdependence of species in various ecosystems. Test your understanding of how life has evolved and adapted over billions of years.
