Unit 1 Flashcards
(21 cards)
Modern Cell theory
- smallest unit of life
- living things made of cells
- cells come from other cells
4 Criteria for defining life + brief explain
- evolutionary history (“family tree”)
- all life related to a common ancestor (has a history: past and future) - the physical organization of life (Cells)
- if made of a physical organization like other living things can be considered living - chemical makeup of life (essential molecules)
- all life shares deep structure on the molecular level
- Activities of life (metabolism, synthesis etc..)
- fundamental processes
Explain activities of life
Nutrition
Respiration
Synthesis
Excretion
Response
Homeostasis
Growth
Reproduce
Living system
- conversion of energy and matter (metabolism)
- maintain homeostasis
- replicate itself
Virus living or not?
- don’t have cell structure and can’t reproduce without host
- unclear if maintain homeostasis
- generally not considered alive
Evolutionary history
All forms of life came from single/simple organisms (LUCA)
- most likely looked like bacteria
- made of organic molecules (hydrogen+carbon atoms)
eg: Disease resistance
Formation of atmosphere
-4.6 billion years ago
- initially gases from the foundation of the solar system then later volcanic gases
-atmosphere cooled enough for rocks and liquid water
4 stages of formation of life
Stage 1(chemical):
- conditions were right to form many gases as earth cooles
- inorganic gases synthesized to produce organic molecules
Stage 2 (chemical):
- synthesis reaction over and over to make chain of molecules (polymers) due to right conditions
Stage 3 (biological)
- Polymers enclosed in plasma membrane to form protocell
Stage 4 (biological)
- protocell undergoes biological evolution to make first real cell (self replicating)
- first cells continue evolution with single living lineage
Phylogenic Tree
Three domains contain all life
Bacteria
- unicellular, Prokaryotic (no nucleus)
- found anywhere
- eg: E. coli
Archea
- Bacteria like
- unicellular, Prokaryotic (no nucleus)
- Hostile environment
- closer related to Eukarya
Eukarya
- True Nucleus
- closer related to archea
- Kingdoms: animals, plant, fungi, protists
Binomial Nomenclature
- 2 name system
- Genus first (cap)
- Species second (not cap)
- Both works italicized, bolded, or underlined
Taxonomy Catagories (largest to smallest)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Cladogram and clades
Cladogram:
- allows to inspect evolutionary history
Clades:
- a group that has common ancestor and includes all descendants
Independent confirmation
2 independent pieces of evidence that support same pattern and increases confidence in answer
eg: darwin and Wallace concluded same thing about natural selection
Homology (EFE)
- a trait from a common ancestor and in related species
a) morphological/anatomical phonological structure
b) embryonic development
c) vestigial Structure
d) behaviour (innate vs learned)
e) Molecular biology
Fossils (EFE)
Transitional links
- fossils that have traits of ancestors and descendants
- represents evolutionary shifts (life changed)
- supports continental drift theory
Biogeography (EFE)
the study of the geographical distribution of organisms provides information about how and when species may have evolved
-continental drift theory
Continental drift theory
Darwin found species in same continent but different environments where closer related than ones from diff content but same ecosystem
- supports that continents drifted then formation of descendants
- MORE SIMILAR BASED ON LOCATION VS ECOSYSTEM
- change of landscape goes with change of life
Direct Observation (EFE)
you can observe similar characteristics in diff species
eg: average depth of finch varies from generation based on the amount of rainfall
separation — adaption —- separation — adapt — division — repeat
Theory of natural selection
Observations:
- each gen population produces more offspring than adults (exp, growth) (a)
- population doesn’t grow (a)
- resources are limited (a)
- Individuals vary (B)
-Many variations are heritable (b)
Inferences:
(a) Individuals in the population compete for resources
(b) some heritable traits are advantageous to surviving
Conclusion:
over time population changes as advantageous heritable trait characteristic becomes more common gen after gen
jean baptiste lamarck vs charles darwin
Lamarck’s theory was called the theory of acquired characteristics and Darwin’s was called the theory of evolution by natural selection
Darwin was right as acquired traits can’t be passed down
convergent evolution
when two organisms that lack a recent common ancestor end up more and more alike as they adapt to a similar environment
