Biology Chapter 1: Evolution, Themes of Bio and Scientific inquiry
Bio: the study of life
- Organization: can be studied in different levels, from molecular to entire planet
- Emergent properties: result from the arrangement and interaction of parts as complexity
increases (photosynthesis)
- Reductionism: involves studying the isolated components of bio systems
Cell: the smallest unit of an organization that can perform all activities required for life
- Cell theory: all living organisms are made of cells
- Every cell is enclosed by a membrane that regulates passage of materials b/w the cell and
its environment
- Eukaryotic cells: membrane enclosed organelles, largest= nucleus
- Prokaryotic cells: simpler, usually smaller and DOES NOT contain a nucleus/ other
membrane-enclosed organelles.
DNA: structures called chromosomes that contain genetic material
- Each chromosome contains one long DNA molecule with hundreds or thousands of
regions, called genes.
- Genes contain info for building the molecules synthesized within the cell
The genetic information encoded by DNA directs the development of an organism
- Each DNA molecule is made up of two long chains arranged in a double helix
- Each chain is made up of four kinds of chemical building blocks called nucleotides
and abbreviated A, G, C, and T.
Gene expression: is the process of converting information from gene to cellular product
- Provide the blueprint for making a protein a cell needs
- DNA is transcribed into RNA, which is then translated into a protein
Genomics: large scale analysis of DNA sequences
- The study of whole sets of genes in one or more species
Proteomics: is the study of whole sets of proteins and their properties
- The entire set of proteins expressed by a given cell, tissue, or organ is called a proteome.
Bioinformatics: the use of computational tools to process a large volume of data very rapidly.
- Interdisciplinary research teams
,Theme: life requires the transfer and transformation of energy and water
- Cellular work requires energy
- The chemical energy generated by plants and other photosynthetic organisms
(producers) is passed along to consumers
- Consumers are organisms that feed on other organisms or their remains
Theme: From molecules to ecosystems, INTERACTIONS are important in biological systems
Interactions between the components of the system ensure smooth integration of all the
parts and function as a whole.
- This holds true across organization levels in biology ranging from molecules in a cell and
the components of an ecosystem.
Feedback: process can self-regulate
Feedback regulations: the output/product of a process and regulates that very process
- The most common form of regulation is negative feedback, in which the response
reduces the initial stimulus
Ecosystems: an organism’s interactions with other organisms and the physical environment
Evolution: concept that living organisms are modified descendants of common ancestors
- Each species is given a two-part name
- Genus: to which the species belongs
- Species name that is unique to that species
The three domains of life
- Bacteria (prokaryotes)
- Archaea (prokaryotes)
- Eukarya (eukaryotic organisms)
Domain Eukarya includes the four subgroups
- Plants
- Fungi
- Animals
- Protists
Natural Selection (Charles Darwin): individuals best suited to their environment are more
likely to survive and reproduce. Over time, more individuals in a population will have
advantageous traits.
Science means “to know”
, - Inquiry: the search for information and explanations of natural phenomena.
Use a process of inquiry that includes making observations, forming logical hypotheses, and
testing them.
Data: recorded observations
- Qualitative data: often take the form of recorded descriptions
- Quantitative data: expressed as numerical measurements organized into tables and
graphs
Collection and Analysis of observations can lead to conclusions using inductive reasoning
Inductive reasoning: derives generalizations from a large number of specific observations
- Ex: all organisms are made of cells
Hypothesis: an explanation based on observations and assumptions, that leads to a testable
prediction
- Must be testable
Experiment: a scientific test, carried out under controlled conditions
Deductive reasoning: uses general premises to make specific predictions.
- Initial observations may give rise to multiple hypotheses (if...then logic)
- Ex: if all organisms are made of cells, and humans are organisms, then humans are made
of cells
The goal of science is to understand natural phenomena
The goal of technology is to apply scientific knowledge for some specific purpose
, Biology Chapter 2: Chemical Context of Life
Negative feedback: corrections return to normal levels
- High glucose= insulin decreases, low glucose= glucagon increases
Positive feedback: amplify or increase the change (moves away from normal state)
- Damage tissue releases chem to start platelet activation->platelets activate->platelets
release more chems. or labor contractions
Matter consists of chemical elements in pure form and in combinations called compounds
- Organisms are composed of matter
- Matter: anything that takes up space and has mass
- Matter exits in various forms like rocks, metals, oils, and gases
- The numerous elements make up matter.
Element: is a substance that cannot be broken down to another substance using chemical
reactions (92 elements found in nature).
Compound: is a substance that contains two or more elements combined in a fixed ratio
- Has emergent properties different from those of its elements.
Essential elements: about 20-25% of the 92 elements that are required for life
- Carbon, hydrogen, oxygen, and nitrogen make up 96% of living matter
Trace elements: are required by an organism in only minute quantities.
An element’s properties depend on the structure of its atoms
- Each element consists of unique atoms
Atom: the smallest unit of matter that still retains the properties of an element
- Composed of subatomic particles
Subatomic particles-
- Neutrons (no electrical charge)
- Protons (positive charge)
- Electrons (negative charge)
Atomic nucleus: formed by neutrons and protons
Electrons form a “cloud” of negative charge around the nucleus
Neutrons mass and proton mass are almost identical and are measured in Daltons and atomic
mass units.
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