SG1 Quiz

If the cell you just drew was a typical living cell of a prokaryote, about how big would it be?

1-5 micrometers long, 1 micrometer wide

About how many different proteins are contained within a single cell of E. coli?

1900

What is the optimal temperature for humans?

25 degrees celsius

How old are the oldest fossils?

3.5 billion years old

What is a ribosome and what does it do?

A ribosome is a particle located in the cytoplasm of cells and it carries out the process of making proteins

Choose from below descriptions that would allow you to distinguish between a prokaryotic cell and a eukaryotic cell. (Select all that apply) a) Eukaryotes have membrane enclosed organelles; prokaryotes have no organelles. b) Eukaryotic cells are usually bigger than prokaryotic cells. c) Eukaryotic cells are structurally more complex than prokaryotic cells. d) Eukaryotic cells have DNA present in linear molecular within the nucleus; prokaryotic cells have circular DNA.

All of the above

This prokaryotic cell you drew could represent...

An archaen or a bacterium

Below are examples of an organisms that flourishes at high temperatures. Match the genus of the organism with the domain and the optimal temperature at which this organism flourishes? Archaea, 106℃ Bacteria, 50-95℃ Bacteria, 85-95℃ 1. Pyrolobus 2. Aquifex 3. Thermotoga

Archaea, 106- 1. Pyrolobus Bacteria, 50-95- 3. Thermotoga Bacteria, 85-95- 2. Aquifex

Which of the phylogenetic tree illustrates the relationships of the three domains of cellular life (not including viruses)? a) Bacteria & Archaea on branch then Eukaryotes on separate branch b) Eukaryotes & Archaea on branch then Bacteria on separate branch c) Eukaryotes & Bacteria on branch then Archaea on separate branch

B) Eukaryotes Archaea - Bacteria

On the phylogenetic tree of life, which domains constitute the prokaryotes?

Bacteria Archaea

Name the biologist who pioneered our understanding of the major domains of life.

Carl Woese

How does the model organism E. coli make a living (i.e., it is what kind of -troph?)?

Chemoorganotroph

Most culturable microbes make a living in which way?

Chemoorganotrophic

Where are ribosomes located in prokaryotic cells?

Cytoplasm

Where are ribosomes located in eukaryotic (somatic) cells?

Cytoplasm rER Mitochondria Chloroplasts

What is the name of the lineage or genus known to be the most radiation-resistant group of organisms?

Deinococcus

Select correct descriptions of the organization and characteristics of the genetic material in a prokaryotic cell. (Select all that apply) a) Double-stranded DNA b) Nucleus c) Circular DNA d) Nucleoid e) Haploid f) May have plasmids

Double-stranded DNA Circular DNA Nucleoid Haploid May have plasmids

Which position (A to E) in the tree you select in Q18 is the LUCA - the last, universal common ancestor of cellular life ? A B C D E

E

What word is used to describe these and other microbes that flourish under conditions unfavorable to humans?

Extremophiles

All cells have a cell wall

False

All organisms that cause disease in humans are monophyletic.

False

Only Gram-positive bacteria cause disease in humans.

False

Viruses can replicate outside host cells

False

What is meant by the genome of an organism?

It is all the genetic information that makes up a given organism

What are the major components of the cytoplasm?

Macromolecules Ribosomes Small organic molecules Inorganic ions

Draw and label the major components of a prokaryotic cell

NO ANSWER

Examine the current perspective on the phylogeny of bacteria presented in BR2. Answer following questions(Q43-Q45).

NO ANSWER

Are Bacteria ancestors of Eukarya?

No, both are derived from LUCA

Are microbes monophyletic?

No, they are polyphyletic.

Do all organisms have ribosomes?

No, viruses do not have ribosomes

What are the three major ways in which microbes 'make a living'? Match with correct description. Obtains energy from organic compounds Obtains energy from inorganic compounds Uses light as energy through photosynthesis 1. phototroph 2. chemoorganotroph 3. chemolithotroph

Obtains energy from organic compounds- 2. Obtains energy from inorganic compounds- 3. Uses light as energy through photosynthesis- 1.

What is the phylogenetic tree based on? Why are those data especially useful in inferring the tree of life?

SSU ribosomal RNA or SSU rRNA because they have been conserved very well across every life form and there is ample amount of SSU rRNA which makes it ideal for determining phylogenetics

What lineage is responsible for the human diseases syphilis and Lyme disease?

Spirochetes

What does Env-OP mean?

The unculturable environmental samples from which the ribosomal RNA genes are isolated and sequenced.

All cells have a cell membrane

True

All cells have cytoplasm

True

All prokaryotes known to cause disease in humans are Bacteria.

True

Most life on Earth is prokaryotic - both in terms of number of species and number of cells.

True

The Proteobacteria contain the majority of Gram-negative species.

True

Viruses are microorganisms

True; they are microorganisms but they are not cells

Do all cells have ribosomes?

Yes, because ribosomes aid in protein synthesis which is useful for carrying out cellular functions

Are Archaea more closely related to Eucarya than to bacteria?

Yes, in the tree they are sisters to each other.

Which of the following Bacteria is/are Gram-positive? Select all that apply. a) Staphylococcus b) Escherichia c) Streptococcus d) Lactobacillus

a c d

What is a gene?

a sequence of genetic material (either DNA or RNA) that codes for a specific trait that was inherited by the given organisms ancestors

What characteristic(s) do all Gram-positive bacteria share? (Select all that apply) a) Thick peptidoglycan cell wall b) Single membrane c) Endospore-forming d) Outer membrane e) None of the above

a) b)

What domains of life are represented among the oldest fossils? (Select all that apply) a) Archaea b) Bacteria c) Eukarya

a) b)

What evidence suggests that some organelles arose via endosymbiosis? (Select all that apply) a) Mitochodria and chloroplasts have their own genome. b) Mitochodria and chloroplasts have double membranes. c) Plylogenetic analysis places mitochodria and chloroplasts with bacterial lineages. d) None of the above.

a) b) c)

Choose the correct description of LUCA (the last universal common ancestor of cellular life). (Select all that apply) a) Prokaryote-like cell b) Single cell c)Autotrophic d) Heterotrophic e) Small cell f) Few or no internal membrane-bound structures g) Small genome h) None of the above

a) b) c) e) f) g)

Which lifestyle(s) is/are autotrophic? a) Phototroph b) Chemoorganotroph c) Chemolithotroph

a) phototroph c) chemolithotroph

How can we conclude that organisms are present in the environment if we never culture them? a) They can be found under microscopes. b) We can easily isolate ribosomal RNA genes or other genomic components from cells existing in a natural sample. c) a and b. d) None of the above.

b)

Which lifestyle(s) is/are heterotrophic? a) Phototroph b) Chemoorganotroph c) Chemolithotroph

b) chemoorganotroph

What evidence do we have that life originated on a 'warm planet'? a)Several lineages of Bacteria branch off very early on the phylogenetic tree, very near the root. b) These groups are unified by the common property of growth at high temperature (thermophily). c) a and b d) None of the above

c)

Define endosymbiosis.

one organism living inside another as both live interdependently. This is how mitochondria and chloroplasts came from bacteria and each ended up as a feature of certain eukaryotic cells

Do many eukaryotic cells depend on endosymbionts for energy? Explain.

yes because the mitochondria is considered the powerhouse of the cells it inhabits as it supplies energy, and chloroplasts do the same thing for plant cells