BIOL 1001 EXAM 1 QUESTIONS AND
ANSWERS 2026 VERIFIED.
What question do scientists debate about viruses like Ebola? - ANS Scientists debate whether
viruses are truly living organisms because while they share some features with living things
(e.g., reproduction inside host cells), they lack characteristics like independent metabolism and
cellular structure.
What are the characteristics of life that all organisms share? - ANS Actively maintain
organized complexity; Acquire and use materials and energy (metabolism); Sense and respond
to stimuli; Maintain homeostasis; Grow and develop; Reproduce (sexually or asexually); Evolve
as populations over time
What is homeostasis? - ANS Homeostasis is the ability of organisms to maintain stable
internal conditions (e.g., temperature, pH) despite external changes.
What are the two main cell types? - ANS Prokaryotic cells: Lack a nucleus and organelles;
unicellular; include Bacteria & Archaea. Eukaryotic cells: Have a nucleus & organelles; can be
unicellular or multicellular; include plants, animals, fungi, protists.
What is the function of the nucleus in eukaryotic cells? - ANS The nucleus stores the cell's
DNA and controls cell activities, including protein synthesis and reproduction.
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,What separates a cell from its environment? - ANS A plasma membrane encloses the cell,
containing cytoplasm inside and regulating what enters and leaves.
What are the two main ways organisms acquire energy? - ANS 1. Photosynthesis
(Phototrophs): Use sunlight to make energy-rich molecules (ATP) and synthesize sugars from
CO₂. 2. Consumption (Chemotrophs): Use chemical reactions (oxidation) or organic matter for
energy.
What is the difference between autotrophs and heterotrophs? - ANS Autotrophs make their
own food (e.g., plants using photosynthesis). Heterotrophs must consume other living or dead
organisms for energy.
What are chemolithotrophs? - ANS Organisms that obtain energy by oxidizing inorganic
compounds like hydrogen sulfide (H₂S) or ammonia (NH₃); use CO₂ to build organic molecules.
What is the difference between energy flow and nutrient cycling? - ANS Energy flows one
way (eventually lost as heat), while nutrients (e.g., water, minerals) cycle repeatedly through
ecosystems.
How do organisms respond to stimuli? - ANS They use energy to detect and respond to
changes in their environment (e.g., animals sense light, temperature; plants bend toward
sunlight).
How do mammals maintain a stable internal temperature? - ANS Through homeostasis
mechanisms like sweating to cool the body when external temperatures rise.
How do organisms grow and develop? - ANS Single-celled organisms enlarge and divide
(asexual reproduction). Multicellular organisms grow via cell division (mitosis/meiosis) and
often develop more complexity as they mature.
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, What is DNA and what does it do? - ANS DNA (deoxyribonucleic acid) stores genetic
information, encodes proteins, and is passed to offspring during reproduction.
How do mutations occur? - ANS Errors in DNA replication by enzymes; Damage by mutagens
like radiation or pollutants; Can be neutral, harmful, or beneficial to survival.
What is evolution? - ANS Evolution is the process by which populations accumulate genetic
changes over time, driven by mutation, natural selection, and adaptation, leading to the
diversity of life.
Who proposed the theory of evolution by natural selection? - ANS Charles Darwin and Alfred
Wallace in the mid-1800s.
What causes extinction? - ANS If species cannot adapt genetically to changing environments,
they may go extinct (e.g., dinosaurs after environmental changes).
List the levels of biological organization from smallest to largest. - ANS Atom → Molecule →
Cell → Tissue → Organ → Organ system → Organism → Population → Community → Ecosystem
→ Biosphere
What is a community vs an ecosystem? - ANS Community = all interacting populations in an
area. Ecosystem = community + its physical environment (air, water, soil).
What are the three domains of life? - ANS 1. Bacteria - Prokaryotic, no nucleus, simple cells 2.
Archaea - Prokaryotic, unique adaptations, some traits like eukaryotes 3. Eukarya - Eukaryotic
cells with nuclei & organelles
What are the four kingdoms of Eukarya? - ANS Animalia: multicellular, heterotrophic, no cell
walls, motile Plantae: multicellular, photoautotrophic, cell walls of cellulose Fungi: mostly
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ANSWERS 2026 VERIFIED.
What question do scientists debate about viruses like Ebola? - ANS Scientists debate whether
viruses are truly living organisms because while they share some features with living things
(e.g., reproduction inside host cells), they lack characteristics like independent metabolism and
cellular structure.
What are the characteristics of life that all organisms share? - ANS Actively maintain
organized complexity; Acquire and use materials and energy (metabolism); Sense and respond
to stimuli; Maintain homeostasis; Grow and develop; Reproduce (sexually or asexually); Evolve
as populations over time
What is homeostasis? - ANS Homeostasis is the ability of organisms to maintain stable
internal conditions (e.g., temperature, pH) despite external changes.
What are the two main cell types? - ANS Prokaryotic cells: Lack a nucleus and organelles;
unicellular; include Bacteria & Archaea. Eukaryotic cells: Have a nucleus & organelles; can be
unicellular or multicellular; include plants, animals, fungi, protists.
What is the function of the nucleus in eukaryotic cells? - ANS The nucleus stores the cell's
DNA and controls cell activities, including protein synthesis and reproduction.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 18
,What separates a cell from its environment? - ANS A plasma membrane encloses the cell,
containing cytoplasm inside and regulating what enters and leaves.
What are the two main ways organisms acquire energy? - ANS 1. Photosynthesis
(Phototrophs): Use sunlight to make energy-rich molecules (ATP) and synthesize sugars from
CO₂. 2. Consumption (Chemotrophs): Use chemical reactions (oxidation) or organic matter for
energy.
What is the difference between autotrophs and heterotrophs? - ANS Autotrophs make their
own food (e.g., plants using photosynthesis). Heterotrophs must consume other living or dead
organisms for energy.
What are chemolithotrophs? - ANS Organisms that obtain energy by oxidizing inorganic
compounds like hydrogen sulfide (H₂S) or ammonia (NH₃); use CO₂ to build organic molecules.
What is the difference between energy flow and nutrient cycling? - ANS Energy flows one
way (eventually lost as heat), while nutrients (e.g., water, minerals) cycle repeatedly through
ecosystems.
How do organisms respond to stimuli? - ANS They use energy to detect and respond to
changes in their environment (e.g., animals sense light, temperature; plants bend toward
sunlight).
How do mammals maintain a stable internal temperature? - ANS Through homeostasis
mechanisms like sweating to cool the body when external temperatures rise.
How do organisms grow and develop? - ANS Single-celled organisms enlarge and divide
(asexual reproduction). Multicellular organisms grow via cell division (mitosis/meiosis) and
often develop more complexity as they mature.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 18
, What is DNA and what does it do? - ANS DNA (deoxyribonucleic acid) stores genetic
information, encodes proteins, and is passed to offspring during reproduction.
How do mutations occur? - ANS Errors in DNA replication by enzymes; Damage by mutagens
like radiation or pollutants; Can be neutral, harmful, or beneficial to survival.
What is evolution? - ANS Evolution is the process by which populations accumulate genetic
changes over time, driven by mutation, natural selection, and adaptation, leading to the
diversity of life.
Who proposed the theory of evolution by natural selection? - ANS Charles Darwin and Alfred
Wallace in the mid-1800s.
What causes extinction? - ANS If species cannot adapt genetically to changing environments,
they may go extinct (e.g., dinosaurs after environmental changes).
List the levels of biological organization from smallest to largest. - ANS Atom → Molecule →
Cell → Tissue → Organ → Organ system → Organism → Population → Community → Ecosystem
→ Biosphere
What is a community vs an ecosystem? - ANS Community = all interacting populations in an
area. Ecosystem = community + its physical environment (air, water, soil).
What are the three domains of life? - ANS 1. Bacteria - Prokaryotic, no nucleus, simple cells 2.
Archaea - Prokaryotic, unique adaptations, some traits like eukaryotes 3. Eukarya - Eukaryotic
cells with nuclei & organelles
What are the four kingdoms of Eukarya? - ANS Animalia: multicellular, heterotrophic, no cell
walls, motile Plantae: multicellular, photoautotrophic, cell walls of cellulose Fungi: mostly
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 18
