bio exam 1

Question 1

What is peptidoglycan?

Answer 1

A polymer that forms the cell wall of many bacteria

It provides structural support and protection to bacterial cells.

Question 2

Define prokaryotes.

Answer 2

Single-celled organisms without a nucleus

Examples include bacteria and archaea.

Question 3

What is the role of histones?

Answer 3

Proteins that help package DNA into nucleosomes

They are crucial for DNA organization in eukaryotic cells.

Question 4

Define autotroph.

Answer 4

Organisms that produce their own food from inorganic substances

Examples include plants and some bacteria.

Question 5

What is horizontal gene transfer?

Answer 5

The transfer of genetic material between organisms in a manner other than traditional reproduction

It plays a significant role in the evolution of prokaryotes.

Question 6

What is a nucleoid?

Answer 6

The region in a prokaryotic cell where the genetic material is located

It is not surrounded by a membrane.

Question 7

Define heterotroph.

Answer 7

Organisms that obtain their food by consuming other organisms

Most animals and many fungi are heterotrophs.

Question 8

What are ether-linked phospholipids?

Answer 8

Phospholipids with ether bonds, found in some archaea

They differ from the ester-linked phospholipids found in bacteria and eukarya.

Question 9

What is a nucleosome?

Answer 9

A structural unit of a eukaryotic chromosome

It consists of a segment of DNA wrapped around histone proteins.

Question 10

What is a chemo(litho)troph?

Answer 10

Organisms that obtain energy by oxidizing inorganic compounds

They are key players in nutrient cycling.

Question 11

Define antibiotic resistance.

Answer 11

The ability of bacteria to survive and grow in the presence of antibiotics

It poses a significant challenge in treating bacterial infections.

Question 12

What is an antibiotic?

Answer 12

A substance that kills or inhibits the growth of bacteria

They are used to treat bacterial infections.

Question 13

What is binary fission?

Answer 13

A method of asexual reproduction in prokaryotes

It involves the division of a single cell into two identical cells.

Question 14

Define phototroph.

Answer 14

Organisms that obtain energy from light

Examples include plants and some bacteria.

Question 15

What does MRSA stand for?

Answer 15

Methicillin-resistant Staphylococcus aureus

It is a strain of Staphylococcus that is resistant to many antibiotics.

Question 16

What does CRE stand for?

Answer 16

Carbapenem-resistant Enterobacteriaceae

These are bacteria that have developed resistance to carbapenem antibiotics.

Question 17

List three beneficial roles of prokaryotes.

Answer 17

• Decomposing organic matter
• Fixing nitrogen
• Producing antibiotics

Prokaryotes play essential roles in ecosystems and human health.

Question 18

Explain why antibiotics specifically kill bacteria instead of the host.

Answer 18

Antibiotics target specific bacterial structures or functions not present in human cells

This selective toxicity minimizes harm to the host.

Question 19

Explain why antibiotics that kill many different species of bacteria tend to cause side effects for the host.

Answer 19

They disrupt the balance of normal flora in the host, leading to opportunistic infections

This can result in conditions like antibiotic-associated diarrhea.

Question 20

What characterizes viruses as obligate intracellular parasites?

Answer 20

They can only replicate inside a host cell

They lack cellular machinery for independent reproduction.

Question 21

Why are viral diseases difficult to treat with drugs?

Answer 21

Viruses utilize host cellular machinery for replication, making it hard to target them without harming the host

This complicates the development of antiviral medications.

Question 22

Name a synapomorphy of the taxon containing the Archaea and Eukarya.

Answer 22

Presence of histones in their DNA

This characteristic distinguishes them from bacteria.

Question 23

Are Archaea more closely related to Bacteria or Eukarya?

Answer 23

Eukarya

Molecular studies have shown a closer evolutionary relationship.

Question 24

Identify whether organisms with histones form a monophyletic group.

Answer 24

Yes, they are monophyletic

This group includes Archaea and Eukarya.

Question 25

Was the common ancestor of all species living today prokaryotic or eukaryotic?

Answer 25

Prokaryotic ## Footnote All life on Earth is believed to have descended from prokaryotic ancestors.

Question 26

Will Archaea stain gram positive or gram negative?

Answer 26

Gram negative ## Footnote This is due to their unique cell wall structure.

Question 27

Will Eukarya stain gram positive or gram negative?

Answer 27

Varies; some stain gram positive, others gram negative ## Footnote This depends on the specific organism and its cell wall composition.

Question 28

What are drawbacks to killing 99.9% of all household bacteria?

Answer 28

Potential disruption of normal flora and emergence of resistant strains ## Footnote Killing beneficial bacteria can lead to health issues.

Question 29

Describe a negative consequence of regularly using broad spectrum antibiotics.

Answer 29

Disruption of normal gut microbiota, leading to opportunistic infections ## Footnote This can result in conditions such as Clostridium difficile infection.

Question 30

Label the following stage: Exit from host cell.

Answer 30

Release of new virions from the infected host cell ## Footnote This is a critical step in the virus's life cycle.

Question 31

Label the following stage: Host cell entry.

Answer 31

Virus attaches to host cell and injects its genetic material ## Footnote This marks the beginning of viral replication.

Question 32

Label the following stage: New virions assembly.

Answer 32

Formation of new viral particles from replicated components ## Footnote This occurs after the viral genome has been replicated.

Question 33

Label the following stage: Transmission to a new host.

Answer 33

Spread of the virus to another organism ## Footnote This ensures the continuation of the viral life cycle.

Question 34

Label the following stage: Viral protein production.

Answer 34

Synthesis of proteins necessary for new virions ## Footnote This occurs after the viral genome is replicated.

Question 35

Label the following stage: Viral genome replication.

Answer 35

Duplication of the virus's genetic material ## Footnote This is essential for the production of new virions.

Question 37

Define a monophyletic group

Answer 37

A group that includes an ancestor and all its descendants ## Footnote Monophyletic groups are essential for understanding evolutionary relationships.

Question 38

What is systematics?

Answer 38

The scientific study of the diversity of organisms and their relationships ## Footnote Systematics combines taxonomy and phylogenetics.

Question 39

What does a node represent in a phylogenetic tree?

Answer 39

A point where a branch splits, representing a common ancestor ## Footnote Nodes are crucial for understanding evolutionary divergence.

Question 40

Define character states

Answer 40

The observable traits or characteristics of an organism ## Footnote Character states are used to determine evolutionary relationships.

Question 41

What is colonialism?

Answer 41

The practice of acquiring control over another country, occupying it with settlers, and exploiting it economically ## Footnote Colonialism has significant historical implications for scientific classification.

Question 42

What is a branch in a cladogram?

Answer 42

A line that represents the evolutionary pathway of a taxon ## Footnote Branches illustrate the relationships among different groups.

Question 43

Define taxon

Answer 43

A group of one or more populations of organisms that form a unit ## Footnote Taxa can be species, genera, families, etc.

Question 44

What is Systema Naturae?

Answer 44

A work by Carolus Linnaeus that laid the foundations for modern taxonomy ## Footnote It introduced hierarchical classification and binomial nomenclature.

Question 45

What does phylogeny refer to?

Answer 45

The evolutionary history and relationships among species or groups ## Footnote Phylogenetic studies are essential for understanding biodiversity.

Question 46

Define outgroup

Answer 46

A species or group that is closely related to the ingroup but not part of it ## Footnote Outgroups help in determining the evolutionary relationships within the ingroup.

Question 47

What is taxonomy?

Answer 47

The science of naming, describing, and classifying organisms ## Footnote Taxonomy is critical for organizing biological diversity.

Question 48

Define cladogram

Answer 48

A diagram that shows the evolutionary relationships among a group of organisms ## Footnote Cladograms are based on shared characteristics.

Question 49

What is synapomorphy?

Answer 49

A shared derived characteristic that is used to define a clade ## Footnote Synapomorphies are crucial for constructing cladograms.

Question 50

Define binomial nomenclature

Answer 50

A two-part naming system for organisms, consisting of genus and species ## Footnote Developed by Carolus Linnaeus, it standardizes organism naming.

Question 51

What is a clade?

Answer 51

A group of organisms that includes an ancestor and all its descendants ## Footnote Clades represent branches in the tree of life.

Question 52

What is a tip in a cladogram?

Answer 52

The endpoint of a branch representing a species or group ## Footnote Tips indicate the current state of a lineage.

Question 53

True or False: Racism has influenced the fields of nomenclature and taxonomy.

Answer 53

True ## Footnote Historical racism affected how species were classified and understood.

Question 54

Who is Carolus Linnaeus?

Answer 54

A Swedish botanist who developed the system of binomial nomenclature ## Footnote Linnaeus is often referred to as the father of modern taxonomy.

Question 55

List the properties of life

Answer 55

* Growth and development * Reproduction * Response to stimuli * Homeostasis * Metabolism * Cellular organization * Adaptation through evolution ## Footnote These properties are essential for defining living organisms.

Question 56

Explain evolutionary longhand

Answer 56

A detailed description of how specific traits have evolved over time ## Footnote It can include the adaptive significance of traits.

Question 57

Compare taxonomy and systematics

Answer 57

Taxonomy focuses on classification, while systematics emphasizes relationships and evolution ## Footnote Both are essential for understanding organismal diversity.

Question 58

Identify the parts of a cladogram

Answer 58

* Nodes * Branches * Tips * Clades ## Footnote Understanding these parts helps in interpreting evolutionary relationships.

Question 59

Interpret a cladogram

Answer 59

Make inferences about the evolutionary relationships and character state evolution among groups ## Footnote Cladograms provide visual representations of phylogenetic relationships.

Question 60

Given traits, identify a species you’ve never encountered

Answer 60

Analyze the traits and compare them to known characteristics of bacteria, archaea, protists, plants, fungi, or animals ## Footnote This skill involves applying taxonomic and systematic knowledge.

Question 61

Explain the biological significance of colonialism in taxonomy

Answer 61

Colonialism influenced the naming and classification of organisms, often disregarding indigenous knowledge ## Footnote This has led to a loss of local biodiversity understanding.

Question 62

Describe gains of reverting to indigenous nomenclature

Answer 62

Restoration of cultural identity, improved local understanding of biodiversity, and respect for indigenous knowledge ## Footnote Indigenous nomenclature often reflects ecological relationships.