Studying Life Vodcast 1.3 Unit 1: Introduction to Biology.
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Transcript of Studying Life Vodcast 1.3 Unit 1: Introduction to Biology.
Studying LifeVodcast 1.3
Unit 1: Introduction to Biology
What is Biology?
Biology – the study of life
Biology is the science that seeks to understand the living world
What Characteristics Do All Living Things Share?
Living things are made up of cellsCells are the basic unit of lifeOrganisms are composed of one or more cells – the smallest units
considered aliveDespite their small size, cells are complex and highly organized
Living things are based on a universal genetic codeAll organisms store the complex information they need to live,
grow, and reproduce in a genetic code written in a molecule call DNA
That information is copied and passed from parent to offspring
Living things obtain and use materials and energyAll organisms must take in materials and energy to grow, develop,
and reproduceMetabolism – the combination of chemical reactions through
which an organism builds up or breaks down materials
Characteristics of Living Things Continued…
Living things grow and developEvery organism has a particular pattern of growth and
developmentDuring development, cells divide and differentiate
(they begin to look different from one another and perform different functions)
Living things reproduceAll organisms reproduce, which means that they
produce new similar organismsSexual reproduction – cells from two parents unite
to form the first cell of a new organismAsexual reproduction – a single organism produces
offspring identical to itself
Characteristics of Living Things Continued…
Living things respond to their environmentOrganism detect and respond to stimuli from their
environmentStimulus – a signal to which an organism responds
Living things maintain a stable internal environmentAll organisms need to keep their internal environment
relatively stable, even when external conditions change dramatically
Homeostasis – relatively constant internal physical and chemical conditions that an organism maintains
Taken as a group, living things evolveOver generations, evolution (change over time)
occurs to groups of organismsEvolutionary change links all forms of life to a common
origin more than 3.5 billion years ago
What Are the Central Themes of Biology?
The study of Biology revolves around several interlocking big ideas:
Cellular Basis of LifeLiving things are made up of cellsUnicellular – single-celledMulticellular – consisting of two or more cells
Information and HeredityLiving things are based on a universal genetic code – DNA
Matter and EnergyLiving things obtain and use materials and energyLife requires matter that serves as nutrients to build body
structures, and energy that fuels life’s processesThe need for matter and energy link all living things on Earth in
a web of interdependent relationships
Central Themes in Biology Continued…
Growth, Development, and ReproductionAll living things reproduceDuring growth and development, generalized cells
typically become more and more different and specialized for particular functions
HomeostasisLiving things maintain a relatively stable internal
environment, a process known as homeostasisFor most organisms, any breakdown of homeostasis
may have serious or even fatal consequences
EvolutionTaken as a group, living things evolveEvolutionary theory is the central organizing
principle of all biological and biomedical science
Central Themes in Biology Continued…
Structure and FunctionStructures have evolved in ways that make
particular functions possible
Unity and Diversity of LifeAlthough life takes an almost unbelievable variety of
forms, all living things are fundamentally similar at the molecular level
One great contribution of evolutionary theory is that it explains both the is unity of life and its diversity
Interdependence in NatureAll forms of life on Earth are connected into a
biosphere – “living planet”Within the biosphere, organisms are linked to one
another and to the land, water, and air around themRelationships between organism and their
environments depend on the cycling of matter and the flow of energy
Central Themes in Biology Continued…
Science as a Way of KnowingScience is not a list of facts, but “a way of knowing”The job of scientists is to use observations,
questions, and experiments to explain the natural world in terms of natural forces and events
Successful scientific research reveals rules and patterns that can explain and predict at least some events in nature
Science allows us to take actions that affects events in the world around us
What are the levels of biological organization?
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Levels of Biological Organization
Atoms – basic unit of matter (ex: C, H, N, O)
Molecules – a chemical structure consisting of two or more atoms (ex: DNA, water)
Organelles – the various functional components present in a cell (ex: mitochondria, chloroplast) Cells – basic
unit of life - the structural and functional unit of all living things (ex: plant cell, animal cell)
Levels of Biological Organization
Tissues – made up of a group of cells that work together, performing a specialized function (ex: epidermal tissue, nervous tissue)
Organs – a body part made up of a group of tissues that carries out a particular function in the body (ex: the brain, leaves)
Organ Systems – a team of organs that cooperate in a larger function (ex: nervous system, digestive system)
Levels of Biological Organization
Organism – individual living thing (ex: elephant, tree)
Population – all the individuals of a species living within the bounds of a specific area
Community – the entire array of organisms inhabiting a particular ecosystem
Levels of Biological Organization
Ecosystem – consists of all the living (biotic) things in a particular area along with all the nonliving (abiotic) components of the environment with which life interacts
Biosphere – consists of all life on Earth and all the places where life exists – all of Earth’s ecosystems combined
How Do Different Fields of Biology Differ in Their
Approach to Studying Life?
Biology includes many overlapping fields that use different tools to study life from the level of molecules to the entire planet