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Question 1

Describe the basic requirements for life and justify their role in supporting life.

Answer 1

-Water
-biogenic elements
-Dna
-energy source

Question 2

Evaluate the characteristics of living organisms and identify those that are shared by living organisms only.

Answer 2

-Cellular organization: All living things are made up of cells.
-Metabolism: Chemical reactions that provide energy for cellular functions.
-Homeostasis: Ability to maintain stable internal conditions.
-Growth and development: Increase in size and complexity over time.
-Reproduction: Ability to produce offspring.
Response to stimuli: Reacting to environmental changes.
-Evolution: Genetic changes over generations to adapt to the environment.

Question 3

Use the characteristics of living organisms to evaluate if viruses should be considered living or not.

Answer 3

Viruses do not meet most of the criteria for life, except for reproduction (inside a host) and evolution. Since they lack cells, metabolism, and independent reproduction, most scientists do not classify viruses as living organisms.

Question 4

Describe the basic components that make up a virus.

Answer 4

-genome (DNA)
-Capsule
-envelope
-proteins

Question 5

Explain why antibiotics do not affect viruses.

Answer 5

-viruses have no cell wall
-antibiotics are bacteria killas

Question 6

Explain why a cellular membrane is required for living organisms to carry out many of their functions.

Answer 6

-The membrane controls what enters and exits the cell (homeostasis)
–transports water and nutrients
-prevents harm entering cell

Question 7

Explain what a taxon is.

Answer 7

A group of organisms classified based on shared characteristics.

Question 8

Explain the difference between monophyletic and paraphyletic organismal groups.

Answer 8

-Monophyletic groups represent a complete evolutionary lineage and are used in modern classification.
-Paraphyletic groups exclude some descendants and do not fully reflect evolutionary history.

Question 9

Explain what convergent evolution is and how it relates to analogous structures.

Answer 9

-Convergent evolution occurs when unrelated organisms evolve similar traits due to similar environmental pressures or ecological roles.

Question 10

Differentiate between analogous and homologous structures and give examples of each.

Answer 10

-Homologous structures show common ancestry and divergent evolution.

-Analogous structures result from convergent evolution, where different organisms develop similar adaptations to similar environments.

Question 11

Explain how organic molecules such as amino acids and nucleic acids may have formed on Earth about 4 billion years
ago.

Answer 11

-Likely formed with small common molecules such as CH4, H2O, NH3 and H2.

-Mixture of gases in a lightning strike created amino acids.

Question 12

Explain why the formation of cell membranes and the protocells were essential for life to occur.

Answer 12

-The cell membrane is built up by phospholipids that have polar and non-polar heads.

-Phospholipids may have formed the first protocell.

Question 13

Explain the role RNA (ribonucleic acid) may have played in the early steps leading to life on Earth.

Answer 13

RNA likely self duplicated and made DNA.

Question 14

Describe the likely habitat and energy source of LUCA.

Answer 14

likely near hydrothermal vent marine environments. Archeans ate up yummy inorganic chemicals.

Question 15

Explain THREE characteristics of early prokaryotes.

Answer 15

1. Lack of a Nucleus and Membrane-Bound Organelles
2. Anaerobic Metabolism (Lived Without Oxygen)
3. High Genetic Diversity and Rapid Reproduction

Question 16

Describe what all prokaryotes have in common.

Answer 16

-Lack of nucleus and membrane-bound organelles
-have cell wall
-use horizontal gene transfer to create genetic variation

Question 17

Describe how bacteria and archaea differ

Answer 17

-Many archaea are extremophiles while bacteria have many diverse environments.
-Bacteria have peptidoglycan, archaea do not.
-Bacteria: Ester linked
-Archaea: Ether linked

Question 18

Explain the importance of differentiating between gram-positive and gram-negative bacteria.

Answer 18

Can help choose the right antibiotic during treatment.

Question 19

Differentiate between transformation, transduction and conjugation. (HGT).

Answer 19

Transformation: The process by which bacteria take up free DNA from their environment.

Transduction: The transfer of bacterial DNA from one cell to another via a virus (bacteriophage).

Conjugation: The direct transfer of DNA between bacteria through a pilus

Question 20

Describe several mechanisms that allow extremophiles to cope in extreme
conditions.

Answer 20

-Their membranes can withstand the heat or cold due to their ether linked membrane.

-They have salt and acid resistant proteins.

Question 21

Describe the habitats where chemoautotrophs thrive and give several examples.

Answer 21

-Deep sea hydrothermal vents
-Acidic mines and sulfur springs

Question 22

Describe what caused the “oxygen revolution”.

Answer 22

-Evolution of cyanobacteria is the main contributor to the oxygen evolution because they developed oxygenic photosynthesis.

Question 23

Explain the role of prokaryotes in the carbon and nitrogen cycle.

Answer 23

-They have a unique ability to fixate carbon and nitrogen

-specifically in photosynthesis CO2 is taken and organic compounds are released.

-same goes for nitrogen,
-NH₄⁺ → NO₂⁻ → NO₃⁻

Question 24

Explain why photoheterotrophs such as halobacteria are able to use light as an
energy source.

Answer 24

-Bacteriorhodopsin absorbs light

Question 25

Compare and contrast different modes of metabolism in prokaryotes.

Answer 25

-Photoautotrophs: takes Light, carbon source is CO₂ (fixes carbon) -Photoheterotrophs: takes Light carbon source is Organic Compounds -Chemoautotrophs: takes Inorganic Molecules (H₂, Fe²⁺, NH₃), carbon source is CO₂ (fixes carbon). -Chemoheterotrophs (us): takes in Organic Molecules carbon source is Organic Compounds.

Question 26

Which of the statements below is correct regarding the staining of gram-negative and gram-positive bacteria? A. Gram-negative bacteria stain purple because of their thick peptidoglycan cell wall. B. Gram-positive bacteria stain purple because of their thick peptidoglycan cell wall. C. Gram-positive bacteria stain pink because of their thin peptidoglycan cell wall. D. Gram-negative bacteria stain pink because of their thick peptidoglycan cell wall.

Answer 26

B. Gram-positive bacteria stain purple because of their thick peptidoglycan cell wall.

Question 27

Explain which environmental change that may have promoted the evolution of eukaryotes.

Answer 27

-The Oxygen Increase Led to Eukaryotic Evolution -Endosymbiosis: The Origin of Mitochondria

Question 28

Explain what symbiogenesis is and how it likely led to the evolution of eukaryotes.

Answer 28

-eukaryotic cells evolved through a symbiotic relationship between different prokaryotic cells. - A Larger Prokaryote Engulfed a Smaller one and the mitochondria was born.

Question 29

Evaluate the advantages and disadvantages of sexual reproduction and explain why sexual reproduction is common in eukaryotes.

Answer 29

-Increases Genetic Diversity -Improves Disease Resistance -Eliminates Harmful Mutations -Requires More Energy and Time -Slower Reproductive Rate -Risk of Unsuccessful Mating

Question 30

What is NOT correct about the difference between eukaryotes and prokaryotes? A. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells don’t. B. Most eukaryotes can reproduce sexually, while prokaryotes can’t. C. All eukaryotic organisms are multicellular, while most prokaryotes are not. D. Prokaryotes can live in a wider variety of environments than eukaryotes.

Answer 30

C. All eukaryotic organisms are multicellular, while most prokaryotes are not.

Question 31

Describe the characteristics that all protists have in common.

Answer 31

-nucleus -mitochondria -mostly unicellular

Question 32

Describe the evidence supporting the origin of chloroplasts in photosynthesizing eukaryotes.

Answer 32

-Chloroplasts evolved from free-living cyanobacteria that were engulfed by an ancestral eukaryotic cell. Over time, this symbiotic relationship became permanent

Question 33

Give an example of a protist from each eukaryotic supergroup.

Answer 33

Excavata: Giardia intestinalis Chromalveolata: paramecium Rhizaria: radiolarians Archaeplastida: Chlorophytes (green algae) Amoebozoa: Gymnamoebas Opisthokonta: Choanoflagellates

Question 34

Explain the advantages of multicellularity.

Answer 34

-Different cells can be specialized to do different tasks -increase in size -longer lifespan -complex communication and coordination

Question 35

Describe how some protists are adapted to surviving harsh environmental conditions.

Answer 35

-Dormant structures that resist desiccation -Dormant structures like a cyst can survive unfavorable conditions such as dehydration

Question 36

Describe the characteristics shared by all fungi.

Answer 36

-Cell walls made of chitin -All sessile -Eukaryotic cells -Heterotrophic

Question 37

Explain what extracellular digestion is and how it this process relates to fungi.

Answer 37

-Fungi rely entirely on extracellular digestion for nutrient acquisition. They do not ingest food like animals; instead, they secrete enzymes into their surroundings to decompose organic matter.

Question 38

Describe one difference and one similarity between plants and fungi.

Answer 38

-They are similar as they both have eukaryotic cells. -They are different as they obtain nutrition differently.

Question 39

Distinguish between monokaryotic and dikaryotic hyphae.

Answer 39

Number of Nuclei: Monokaryotic cells have one nucleus, while dikaryotic cells have two.

Question 40

Explain how sexual reproduction in fungi differ from sexual reproduction in plants and animals.

Answer 40

-While plants reproduce sexually by means of seeds, fungi reproduce sexually or asexually through microscopic, unicellular spores, often dispersed by the wind or animals

Question 41

Explain the difference between a parasite, a mutualist and a saprotroph.

Answer 41

Parasite: an organism that lives on or inside another organism (the host) Mutualist: A mutualist is an organism that forms a mutually beneficial relationship with another organism, where both parties gain something of value from the relationship. Saprotroph: A saprotroph is an organism that feeds on decaying organic matter

Question 42

Explain how fungi facilitated early plants on land.

Answer 42

They formed symbiotic relationships with the root of plants. An example being Mycorrhizal fungi.

Question 43

Describe how protists are able to carry out complex functions despite being unicellular.

Answer 43

Their metabolic flexibility, ability to form symbiotic relationships. They also have eukaryotic organelles.

Question 44

Describe the energy source and carbon source for autotrophs, heterotrophs, phototrophs, and chemotrophs.

Answer 44

Autotrophs: Inorganic carbon (CO₂) Heterotrophs: Organic carbon (from other organisms) Phototrophs: can be CO₂ or organic molecules Chemotrophs: can be CO₂ or organic molecules

Question 45

Describe the byproducts of photoautotrophs and chemoheterotrophs.

Answer 45

Phototrophs: Oxygen Chemoheterotrophs: Carbon Dioxide

Question 46

Which polysaccharide is usually found in the cell wall of fungi?

Answer 46

Glycogen

Question 47

Which protist is believed to have evolved following a secondary endosymbiosis?

Answer 47

Brown algae

Question 48

Which fungal phylum is considered the most primitive based on its simple reproductive structures?

Answer 48

Chytridiomycota

Question 49

How do many protists achieve complexity without multicellularity?

Answer 49

Through unique cell shapes and organelle function.

Question 50

What evidence suggests that fungi evolved from an aquatic ancestor?

Answer 50

Presence of flagellated spores in chytrids.

Question 51

Which type of prokaryotes contribute to both the carbon and nitrogen cycles?

Answer 51

Decomposers, cyanobacteria, and archea.

Question 52

A fungal species reproduces primarily through conidia. What can be inferred about this fungus?

Answer 52

It relies mostly on asexual reproduction.

Question 53

Asexually reproducing fungi are HAPLOID or DIPLOID throughout their entire lifecycle!

Answer 53

haploid

Question 54

What is a major function of the coelom (body cavity) in animals?

Answer 54

It serves as a hydrostatic skeleton for support and movement.

Question 55

what are some differences between charophytes and chlorophytes?

Answer 55

-Chlorophytes mostly simple and unicellular. -Charophytes are mostly complex and multicellular.

Question 56

Which environmental conditions did plants have to adapt to in order to thrive on land?

Answer 56

Water Loss & Desiccation Support Against Gravity – Nutrient & Water Uptake –

Question 57

All bilateral animals contain diploblast or triploblasts?

Answer 57

Triploblasts

Question 58

Bilateral animals with a true coelom are classified as either protostomes or deuterostomes based on their patterns of embryonic development. T or F?

Answer 58

True

Question 59

What is cephalization?

Answer 59

Cephalization = Development of a head

Question 60

Which of the following traits are present in red algae, but not in green algae? -Phycoerythrin pigment for photosynthesis -Cell walls -Chlorophyll a -Flagellated sperms

Answer 60

Phycoerythrin pigment for photosynthesis

Question 61

Protostome means “mouth _______”, Deuterostome means mouth _______

Answer 61

protostome: mouth first Deuterostome: mouth second