Week 1 Recall Questions Flashcards
What are the 7 properties of life?
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Displays order
-All forms of life are arranged in someway of organization
-Such as the cells or structures within them, displaying orders. -
Harness and utilizing energy
-Get energy from environment someway and use it to maintain their highly ordered state. -
Reproduce
-Able to make own offspring
-sexual or asexual -
Respond to stimuli
-Make adjustments to structure, behaviour, or function in reaction changes to the external environment/stimuli (Ability to adjust) (more of a short term change) -
Exhibit homeostasis
-Organisms are able to regulate their internal environment such that conditions remain relatively constant. -
Growth and development
-All organisms increase their size by increasing the size and/or number of cells. Many organisms also change over time. -
Evolve
-Populations of living organisms change over the course of generations to become better adapted to their environment. (Long term change)
Viruses?
-Can reproduce and evolve but the ability to reproduce affected by another. Needs another organism in order to reproduce
-Can’t make its own proteins
-Depends on how specific you want to be one labelling what is “life”
What are the 7 properties common to all cells?
- Are bound by a membrane (protective and selective), a lipid bilayer.
- Contain genetic information as DNA
- Show an information transfer from DNA to RNA to protein.
- Have ribosomes to polymerize proteins by using mRNA and tRNA.
- Use proteins as the major structural and catalytic molecule.
- Use ATP as an energy carrier
- Break down glucose through the metabolic pathway of glycolysis
What are some general characteristics of Domain Bacteria?
• Lack internal cell organelles
• ancient linage with diverse evolution (metabolically = live in very diverse environments)
• important roles ecologically especially in decomposition. (Carbon cycle)
• contain peptidoglycan in cell wall (some have lost it but ancestor had it)
• 3 shapes (cocci (circle), bacilli (rod), spirilla (corkscrew))
What are the general characteristics of Domain Archaea?
• lack internal cell organelles
• found widely in oceans, also live in extreme environments
- methanogens, extreme thermophiles, and halophiles
• lack peptidoglycan
• know very little about this group b/c hard to grow in lab
What are the general characteristics of Domain Eukarya?
• found widely across our planet.
• contain a membrane bound nucleus.
• contain organelles (compartmentalization)
• lack peptidoglycan (use other substances in cell walls, similar to Archaea)
• well studied vs Bacteria and Archaea
What is peptidoglycan?
A polymer of sugars and amino acids that forms linear chains.
It makes up most of the cell wall of bacteria. It helps protect cells from external environment and help maintain cells shape.
Do Bacteria have cell organelles?
Most often classified under prokaryotes. Which lack a nucleus and membrane bound organelles. Therefore no.
But I don’t doubt there are exceptions
Do all Bacteria have peptidoglycan?
No. Not all have peptidoglycan as they have lost this trait due to evolution. However, we still see that it is an ancestral character state.
As humans, do we contain healthy bacteria and unhealthy bacteria? What are some of the roles in our human health?
Yes. There are a large number of bacteria in our bodies that help break down food making nutrients available to us. I’m addition to helping defend our bodies from infections.
What is a phylogeny? Sketch the general phylogeny introduced in lecture of the three major Domains. This phylogeny is based on similarities and differences of rRNA sequences. Label the LUCA (last universal common ancestor).
• they represent relationships among organisms in terms of evolutionary history.
What is the problem with using only morphological characteristics to build phylogenetic trees?
2 organisms can have similar characteristics such as structure or function but not share a similar evolutionary history.
Same as 2 organisms can share no physical characteristics but share a evolutionary history.
If you use gene sequences to build a Tree of Life what are three important criteria for what gene you choose to use?
- The specific gene needs to be present in all organisms.
- The gene has to be relatively long. (Larger sequence, more information it contains to make comparisons)
Carl Woese and colleagues built a phylogenetic tree based on what genetic sequences? What three Domains did they describe?
Based on the ribosome = Centre of protein synthesis which uses info in mRNA to synthesize corresponding protein.
A specific gene that codes for rRNA molecule that makes up the small subunit of the ribosome.
“Super kingdoms”: Domains.
Bacteria, Archaea (both showed prokaryotic cell structure)
Eukarya (shower eukaryotic cell structure)
Differentiate between the 3 domains for life
Bacteria-
Chromosome structure: circular
DNA Location: nucleoid
Chromosome segregation: binary fission
Ribosomes: 70s
Membrane Enclosed Organelles: absent
Peptidoglycan in cell wall: present
Temperature tolerance: up to 90°C
Archaea-
Chromosome structure: circular
DNA Location: Nucleoid
Chromosome segregation: binary fission
Ribosomes: 70s
Membrane Enclosed Organelles: absent
Peptidoglycan in cell wall: absent
Temperature tolerance: up to 120°C
Eukarya-
Chromosome structure: linear
DNA Location: Nucleus
Chromosome segregation: meiosis/mitosis
Ribosomes: 80s
Membrane Enclosed Organelles: present
Peptidoglycan in cell wall: absent
Temperature tolerance: up to 70°C
All life forms currently in earth share a common set of attributes or a last universal common ancestor. These attributes are?
- Lipids in a bilayer or membrane that contains the cell.
- A genetic system based on DNA.
- A system of info transfer: DNA —> RNA —> protein.
- A system of protein assembly using messenger RNA and transfer RNA.
- Rely on proteins as major structural and functional molecules.
- Use of ATP as the molecule of chemical energy.
- The breakdown of glucose by the metabolic pathway of glycolysis to generate ATP.
