Chapter 1: Biology, Taxonomy, and Feedback Flashcards
1.1 Hierarchy of Life, Systems Biology, DNA, & Feedback 1.2 Taxonomy, Organization, & Natural Selection 1.3 Scientific Reasoning
Evolution
The process of change that has transformed life on Earth from its earliest beginnings to the diversity of organisms living today.
Biology
Scientific study of life.
Emergent Properties
A property that a complex system or collection of system parts has, but which individual parts do not possess.
Due to arrangement and interactions of parts as complexity increases.
Examples of Emergent Properties
- Photosynthesis occurring in the chloroplast cannot take place in a test-tube mixture of just chlorophyll and chloroplast molecules
- Our thoughts and memories are emergent properties of a complex network of cells (we can’t just create artificial brains that easily).
Reductionism
The approach of reducing complex systems to simpler components that are more manageable to study (especially in complex biological systems).
Systems Biology
An approach that attempts to model the dynamic behavior of whole biological systems based on a study of the interactions among the system’s parts.
Levels of Biological Organization
- Biosphere (The Earth)
- Ecosystem (All things in one area)
- Communities (All organisms in one area)
- Population (All species in one area)
- Organisms
- Organ Systems & Organs
- Tissues
- Cells
- Organelles
- Molecules
Eukaryotic Cell
Subdivided by internal membranes into various membrane-enclosed organelles.
- DNA is enclosed within nucleus and is by far the largest organelle
- Most organelles have their own membranes and all are in the cytoplasm.
- More complex than prokaryotic cells
Prokaryotic Cells
Cells where DNA is not separated from the rest of the cell by enclosure in a membrane-bounded nucleus.
Lacks membrane-enclosed organelles
Which microorganism group(s) are prokaryotic or eukaryotic?
Bacteria and Archaea are entirely prokaryotic.
DNA
Deoxyribonucleic Acid. The substance of genes and units of inheritance which transmit information from parents to offspring, contained in chromosomes.
Its shape is two strands arranged in a double helix.
Nucleotides
Building blocks of DNA, abbreviated A, T, C,G.
4 types of Nucleotides
Adenine
Thymine
Cytosine
Guanine
Gene Expression
The process by which the information encoded in a gene is turned into a function. This mostly occurs via the transcription of RNA molecules that code for proteins or non-coding RNA molecules that serve other functions.
Negative Feedback
Most common form of regulation of a process in which the accumulation of an end product of a process slows that process.
e.g. When a cell makes more ATP than it can use, the excess ATP “feeds back.” The process slows down.
Genome
The entire “library” of genetic instructions that an organism inherits
Positive Feedback
The end product speeds up its own production.
e.g. Clotting of blood during injury. When blood vessels are damaged, more platelets aggregate to seal the wound.
Hierarchy of Biological Classification
From most broad to specific
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
Taxonomy
Branch of biology that names and classifies species, formalizes the ordering of species of increasing degree to which they share charateristics.
The Three Domains
Bacteria, Archaea, and Eukarya
Which domains are prokaryotes?
Bacteria and Archaea are all prokaryotic. Most prokaryotes are single-celled and microscopic.
Which domains are eukaryotes? What kingdoms does this include?
All eukaryotes are grouped in domain Eukarya.
It includes 3 kingdoms of multicellular eukaryotes
1. Plantae
2. Fungi
3. Animalia
How do the 3 multicellular kingdoms of Eukaryotes get distinguished?
Plantae - produce its own sugars and food molecules through photosynthesis
Fungi - absorbs dissolved nutrients from their surroundings
Animalia - Does neither of the two above.
Darwin’s Theory of Natural Selection
Individuals with inherited traits that are best suited to the local environment are more likely to survive and reproduce than less suited individuals.
Natural Selection
Natural environment “selects” for the propagation of certain traits among naturally occurring variant traits in the population
Inductive Reasoning
Derived generalizations from a large number of specific observations.
e.g. “The sun always rises in the east” or “All organisms are made of cells”
Deductive Reasoning
Generally used after hypothesis has been developed. Goes from starting in general premises and leads to specific results that are expected if the premises are true.
The Cell (and the 2 types)
Basic unit of structure and function for organisms. They are either prokaryotes and eukaryotes
