biology notes
biology is the study of living thing biotic things are living abiotic like humans. things are non living like rocks
smallest are atoms then molecules, macromolecules, organelles, then cells being the largest. cells are the basic unit of life. smallest thing that can check off the 5 needed things of life.
living things like bacteria are unicellular while humans are multicellular. cells vary in size shape and complexity.
cells have charateristics like a being enclosed in s membrane.
know the difference between eukaryotes and prokaryotes
Eukaryotes - contains membrane-enclosed organelles, including a
DNA-containing nucleus
larger than prokaryotes cells
Prokaryotes - lack a nucleus or other membrane-bound organelles
and are generally smaller than eukaryotic cells
• Examples: bacteria, archaea
levels of biological organization organismal level
tissues( smallest)
organs
organ system
organism
Population-to-Biosphere level:
• Population (smallest)
same species cats aren’t included
• Community
• Ecosystem made up of biotic and abiotic factors
• Biosphere (largest) includes land water everything.
A SPECIES is a group of a specific type of organisms
summary
cells are the basic unit of life. the two forms are eukaryotes and prokaryotes humans are eukaryotes.
prokaryotes include bacteria and archaea and lack nucleus , membrane-bound organelles
eukaryotes have membrane bound organelles like nucleus animals plants and fungi
Levels of biological organization from smallest to largest:
atoms
molecules
macromolecules (proteins, lipids, carbs)
organelle
cell
tissue
organ
organ system
organism
population
community
ecosystem
biosphere
movement and cognitive thinking aren’t characteristics of life **
all living things require energy to carry out any function
energy is the capacity to do work
metabolism is the chemical process in cells that use/ convert or use energy to sustain life in the organism
the source of energy for all living things is the sun
Autotrophic organisms, like plants, can make their own energy
through processes like photosynthesis
• Heterotopic organisms (like us!) either eat plants or eat other
organisms
homeostasis
is the ability to maintain balance in the body despite the changes to an external environment changes.
Organisms can sense and respond to stimuli to maintain homeostatic
conditions
• Example: body temperature
• Stimulus = hot or cold environment
• Response = sweating or shivering
Growth, development, and reproduction
All living things are capable of growing and producing offspring
• Growth refers to the increase in size of an organism
• Development involves changes across the lifespan of an organism
• Reproduction is the process by which organisms create new individuals
of their species
• Asexual reproduction involves one parent, where as sexual reproduction involves two
living organisms
an adaptation that is any heritable mod that makes an organism better able to function in a specific place
evolution is the change in genetic composition (heritable traits) of a population of organisms over time
DNA
all living things have genetic code that uses DNA
The Central Dogma of Biology describes the one-way flow of genetic
information within a cell
goes from DNA to RNA to protein rna changes what the cells look like.
summary
biotic refers to things that meet the five characteristics
of life, whereas those that do not can be referred to as being
the five characteristics of life
homeostasis,
cellular organization
energy utilization,
growth repair and development
adaptation and heredity
cells are the most basic unit of life
universal genetic code is transmitted via dna
central dogma of biology is Dna to Rna to protein is also the one way flow of information.
Evolution and classification of life
The theory of evolution explains the
diversity and unity of life.
• The theory of evolution suggests that all living
organisms descended from a common ancestor.
• Common descent with modification.
scientific theory vs law
Scientific Theory:
• Concepts that join together two or more well-
supported and related hypotheses.
• Supported by a broad range of observations,
experiments, and data.
scientific Principle/Law:
• Widely accepted set of theories.
• No serious challenges to validity
for example gravity
natural selection
Natural selection is the evolutionary mechanism proposed by Charles
Darwin.
• Some aspect of the environment (“environmental pressure”) selects
which traits are more likely to be passed on to the next generation.
• Individuals with the favorable traits produce the greater number of offspring that survive and
reproduce = “Survival of the fittest”
• This increases the frequency of those favorable traits in a population.
Evolutionary Tree of Life
An evolutionary tree is like a family tree. An evolutionary tree traces the ancestry of life on Earth to a common ancestor.
LUCA –
Last
Universal
Common
Ancestor
not a lot of evidence on luca dude to soft tissue not being able to fossilize like bones
Domain Bacteria
Consists of prokaryotic unicellular organisms that reproduce asexually
• No membrane-bound organelles or nucleus
• Heterotrophic bacteria: non-photosynthetic
bacteria
• Important in ecosystems; keep chemical cycling
going
• Parasitic bacteria cause disease
• Cyanobacteria: large, photosynthetic (autotrophic)
bacteria
• May have been the first organisms to contribute oxygen to early Earth’s atmosphere extremophiles like the archaea in yellow stone Prokaryotic unicellular organisms that reproduce asexually
• Do not undergo photosynthesis; can be both autotrophic and heterotrophic; autotrophic processes are distinct to archaea
• Live in extreme environments thought to be like early Earth
• Plasma membrane and cell wall chemically different from bacterial cell wall
• No membrane-bound organelles or nucleus
Domain Eukarya
unicellular and multicellular organism
Cells with a membrane-bounded nucleus
• Sexual reproduction common
• Heterotrophs and autotrophs
Includes the protists, plants, fungi and animals
bacteria | archaea | Eukarya |
Domain Eukarya Kingdom
Protists are difficult to classify and define; includes unicellular and multicellular organisms that are both heterotrophic and autotrophic
• Fungi are mostly multicellular, saprotrophic organisms that form spores, lack flagella, and have cell walls containing chitin.
• Plants are photosynthetic, multicellular organisms that are primarily adapted to a land environment.
• Animals are motile, multicellular heterotrophic organisms.
bio classification
domain (eu
karayote), kingdom(animalia), phylum(chordata), class(reptilia), order(, family, genus species.
in order from largest to smallest
scientific names
biological names are usually Latin based.
genus being the street species being the address
Chapter 15
the earth is around 3.5- 5 billion years old
diversity came from evolution
phenotype is physical appearance
The simplest definition of evolution is a change in the genetic composition of a population over time (from generation to generation)
ideas of change over time
evolution is the change in a population over time and can grow to turn into new species.
humans are a very young species but made a lot of change. most people assume its a gradual change. geological change comes over time that resulted from gradualism a suggestion from the geologist James Hutton. evolution comes from gradualism which makes new species
Jean-Baptiste de Lamarck Lamarckism is symbolized by giraffes. species evolved from the use or unuse of certain body parts or like learning languages ‘use it or lose it’. you cant evolve with in your own life span. while with Darwinism it has to be linked to DNA. But, his study occurred before the knowledge of DNA.
Charles Darwin grew up with plants, he first studied medicine, and wasnt successful and changed to theology. December 1831: 22-year old Darwin took a position as naturalist for what was supposed to be a two year around-the-world voyage on the HMS Beagle.the voyage was suposed to be 2 years but took 5. he collected thousands of plants and animals. he described features that suited organisms to their enviornments. he looked at fossils resembled living species from the same region , and living species. he noticed that species must have colonized the galapagos.
Darwin’s finches are what show adaptation and evolution
fitness = reproduction
in 1844 he wrote an essay on natural selection and descent and didn’t release it publicly. in june 1858 he got a manuscript from Alfred Russell Wallace.
summary
the simplest definition of evolution is the gradual change in a species’ genetic composition losing unused traits and only pushing on the best genes to the next generation.
An organism’s genotype refers to an organism’s genetic composition or genetics. Any thing that can be inherited by the next generation
Whereas the organism’s phenotype is the physical appearance
scientific hypothesis needs to be testable and falsifiable based on tests and evidence.
a scientific theory is an explaination that is verifys hypothesis and is based on a large amount of experements, test and eventually evidence.
Types of evolution thru selection
natural selection is one of few ways of evolution. It could come from anywhere like artifical and experimental selections. its the only reliable evolution that benefits the population to the enviornment.
INDIVIDUAL ORGSNISMS CANT EVOLVE DURING THEIR LIFE SPAN.
natural selection does used the individuals but only the population can evolve
Artificial selection is when evolution is decided by and outside source like breeding gods. if your looking at one trait