Lecture 2

Question 1

What are 3 characteristics of living organisms?

Answer 1

1. grow and/or survive
2. reproduce
3. pass on characteristic traits to next generation (hereditary)

Question 2

How do all organisms achieve their basic processes?

Answer 2

• organization based on cells bounded by semi-permeable membranes
• ATP based energy currency
• common chemical machinery for the synthesis and degradation of essential molecules
• hereditary via nucleic acids using a common genetic code

Question 3

What are protocells?

Answer 3

simple clusters/bundle of lipids/amino acids, that grow and bud-off, and could form membrane bound vesicles that enclose organic rich media

Question 4

what is the most favored current theory regarding early life?

Answer 4

alkaline deep sea vents very suitable for evolution of earliest life

Question 5

What type of environment are deep sea vents?

Answer 5

thermophilic

Question 6

What are hetertrophs and autotrophs?

Answer 6

heterotrophs: cannot produce its own food

autotrophs: can produce its own food

Question 7

Which evolved first: Autotrophs or Heterotrophs?

Answer 7

Heterotrophs evolved first

Question 8

What is the importance of photosynthesis in regards to early life?

Answer 8

• required specialized pigments
• changed the earth’s atmosphere (ozone, O2)
• greatly influenced the subsequent evolution of life

Question 9

Does the evolution of organisms influence the evolution of environments?

Answer 9

yes

Question 10

what is a biological species?

Answer 10

• reproductive isolation
• a group of natural populations whose members can successfully interbreed with one another and produce viable fertile offspring, but not with members of other such groups

Question 11

What is a morphological species/

Answer 11

differences in structure

Question 12

what is an ecological species

Answer 12

niche differences

Question 13

what is a phylogenetic species?

Answer 13

nucleic acid sequence differences

Question 14

What is a prokaryotic species

Answer 14

• they have strains not species
• strains that share a common set of stable biochemical properties

Question 15

What is systematics?

Answer 15

the study of biological diversity

*the study of evolutionary relationships between all branches of the tree of life

Question 16

What is taxonomics?

Answer 16

• theory and practice of naming and classifying organisms
• framework for classifying ancestral relationships
• assessment and management of biodiversity
• environmental impact assessment

Question 17

what is phylogenetics?

Answer 17

theory and practice of discovering the evolutionary interrelationships among organisms (now mainly DNA based)

Question 18

what are the groups under phylogenetics?

Answer 18

• monophyletic
• paraphyletic
• polyphyletic

Question 19

what is monophyletic?

Answer 19

one that includes a group of organisms descended from a single ancestor

Question 20

what is paraphyletic?

Answer 20

a group of any size and systematic rank that originated from a single common ancestor, but does not – as opposed to a monophyletic group – contain all descendants from this ancestor

Question 21

what is polyphyletic/

Answer 21

organisms that are grouped together despite not being closely related.

Question 22

How do we do our naming?

Answer 22

Genus (italics, capatlized first letter) Species (italics)

Question 23

What is classification based on?

Answer 23

similarities in traits that are supported by DNA sequences

Question 24

What is a virus?

Answer 24

a genome that replicates itself within a host cell by directing the machinery of the host cell to synthesize viral nucleic acids and proteins

Question 25

are viruses organisms?

Answer 25

• lack fundamental cellular features
• do not grow by increasing in size or dividing
• do not respond to external stimulii
• cannot carry on independent metabolism

therefore it can be argued that no, they are not organisms

Question 26

What is the simplified virus replication cycle?

Answer 26

1. the virus enters the cell and is uncoated releasing viral dna and capsid proteins
2. host enzymes replicate the viral genome
3. meanwhile, host enzymes transcribe the viral genome into viral mRNA, which host ribosomes use to make more capsid proteins
4. viral genomes and capsid proteins self assemble into new virus particles, which exit the cell

Question 27

Do viruses have slow or rapid evoltuion?

Answer 27

extremely rapid evolution

Question 28

do viruses have a fossil record?

Answer 28

no

Question 29

what is the possible theory of the origin of viruses?

Answer 29

probably renegade segments of host genomic material that became partially independent

Question 30

Do viruses have a profound impact on life?

Answer 30

yes

Question 31

what is the virus general structure?

Answer 31

• very small
• dna (mainly animal viruses) or rna (mainly plant viruses)
• single or double stranded
• surrounded by protein coding
• some have an outer lipid envelope
• protein coating

Question 32

what is the key for medical treatment against viruses typically?

Answer 32

identifying the protein coating

Question 33

how can viral transmission occur?

Answer 33

• bodily fluids
• animal vectors
• air
• hand contact

Question 34

what is a vaccine?

Answer 34

a preparation of a weakened pathogen or some of its components that primes the organism’s defense mechanisms against the virulent strain

Question 35

what are alternatives to vaccinations?

Answer 35

• antiviral drugs: inhibit reverse transcriptase as it attempts to synthesize dna from the orignal viral rna
• protease inhibitors that block virion protein capsule assembly

Question 36

does the species definition based on the potential for interbreeding work for both plant and animals equally?

Answer 36

• works well for animals
• not so well for plants
• does not apply to prokaryotes

Question 37

how can phylogenetic trees be constructed?

Answer 37

using a wide range of different characteristics including morphological features, pigments, amino acid sequences, dna sequences