characteristics of living things
specific structure
Cells are the basic units of biological organization
All living organisms are composed of one or more cells
Cells are coated by a plasma membrane
Plasma membrane action
Separate cells from the environment
Becomes a gateway for selective exchange of matter and energy between cells and the environment
The difference between cells and inanimate objects
In addition to containing large amounts of water, it also contains a wide variety of organic molecules
Cells are extremely complex and highly ordered systems
All basic metabolic activities required for life can be carried out in cells.
Metabolism
Highlight the attributes of life
a series of enzymatic reactions
In order to maintain metabolism, it is necessary to continuously exchange materials and energy with the environment
An organism is an open system
Capturing free energy from the outside world to drive chemical reactions
autotroph
Obtain energy from sunlight and use simple raw materials to synthesize its own complex organic molecules
Heterotrophs
Decompose food, release its energy, and use the small molecules formed by decomposition as raw materials to synthesize your own biological macromolecules
homeostasis and stress
Steady state
There are many regulatory mechanisms that keep internal conditions relatively stable as the environment changes
Irritability
Feel the changes (stimuli) in the external environment and make responses that are conducive to maintaining homeostasis and maintaining life activities.
reproduction and genetics
The generation of offspring through reproduction allows the continuation of the species
Various reproductive methods
Single-celled organisms such as bacteria divide into two daughter cells to survive
Most organisms reproduce through specialized germ cells
The offspring has traits similar to those of the parents.
Core: DNA replicates itself
The genetic information carried by DNA is expressed as traits along the DNA-RNA-protein pathway.
growth and development
development
closely related to growth
A series of structural and functional changes occur
Precisely controlled programmed change process
evolution and adaptation
evolution
Reasonable explanations for diversity, unity and adaptability
reason
choose
Make each generation of organisms more adaptable to their environment
adapt
Having certain genetic traits that enhance the ability to survive and reproduce in a specific environment
The biological world is a multi-level organizational system
Special fragments at the level of material structure that determine the object and scope of biological research
11 organizational levels form an orderly hierarchy
cell
Specific form and function, unified structural pattern
Plasma membrane-cytoplasm-organelle (has its own specific function)
organize
A cell group that combines one or several types of cells
individual
The basic unit of life that can exist independently in nature
Can consist of one cell or multiple cells
population
Multiple populations of one species
A group of interbreeding individuals of the same species
No genetic exchange due to geographical isolation
Environmental differences and long-term isolation
community
Inseparable from the environment
A collection of multiple biological populations in a space
Populations of different species are mutually restrictive and interdependent
Products that adapt to the local environment and adapt to each other
ecosystem
Within a certain space, biological components and non-biological components are interdependent and mutually restricted through energy flow and material circulation.
biosphere
the sum of all ecosystems
multi-level classification system of the biological world
To study species, we need to identify, name and classify them
swedish botanist linnaeus
Binary nomenclature (two Latin words making up the scientific name of the species)
Second name - species name
Divide each species into a multi-level life system
Each level is called a classification level
If 7 levels are not enough, you can add one level above or below a certain level.
Two-boundary system classification method
three domain classification theory
An organism and its environment form an interconnected network
ecosystem
composition
biological components
The most important connection: nutritional relationship
producer
Capture solar energy and use water and carbon dioxide in the air to create organic matter through photosynthesis
decomposer
Break down complex organic matter into simple organic matter
nutritional relationship
Food chains are interconnected to form a food web
There is a high degree of unity in the vast diversity of the biological world
Cells become the basis of unity in the biological world
same taxon
There are some traits that separate them from each other
A unified structural pattern encompasses them in a classification hierarchy
methods of studying biology
Practice is the standard for testing truth
Science: Social activities with self-healing mechanisms
The essence of scientific method
Insist that any idea, hypothesis, or theory must be testable
system
natural system
closeness of relationship
Virus
Without the basic systems necessary to achieve metabolism, it cannot replicate itself
After contacting the host cell, the protein coat is removed, and the nucleic acid invades the host cell. With the help of the host cell replication system, the new virus is copied according to the viral genetic instructions.
Many biologists believe that it belongs to the intersection area between living and non-living organisms.
Distinguish between living and non-living things
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