Diversity of Life Study Guide (2025/2026 Syllabus)
Unit 1: Introduction to Biological Diversity
1. What is biodiversity?
ANSWER ✓ Biodiversity refers to the variety of life at all levels of biological organization,
including genetic diversity, species diversity, and ecosystem diversity.
2. What are the three main levels of biodiversity?
ANSWER ✓ Genetic diversity (variation within species), species diversity (variety of
species in an area), and ecosystem diversity (variety of habitats and ecological
processes).
3. Who developed the binomial nomenclature system?
ANSWER ✓ Carl Linnaeus developed the binomial nomenclature system for naming
species using genus and species names.
4. What is the correct format for writing a scientific name?
ANSWER ✓ Genus capitalized, species lowercase, both italicized (or underlined if
handwritten), e.g., Homo sapiens.
5. What are the three domains of life?
ANSWER ✓ Bacteria, Archaea, and Eukarya.
6. What distinguishes prokaryotes from eukaryotes?
ANSWER ✓ Prokaryotes lack membrane-bound organelles and a true nucleus, while
eukaryotes have both.
7. What are the key characteristics of the domain Archaea?
ANSWER ✓ Extremophiles often living in harsh environments, distinct cell membrane
composition, and genetic machinery more similar to eukaryotes than bacteria.
8. What is the difference between an autotroph and a heterotroph?
ANSWER ✓ Autotrophs produce their own food (e.g., through photosynthesis), while
heterotrophs consume other organisms for nutrition.
Unit 2: Prokaryotes - Bacteria and Archaea
9. What are the three common shapes of bacterial cells?
ANSWER ✓ Cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped).
, 10. What is the function of bacterial endospores?
ANSWER ✓ Endospores are dormant, highly resistant structures that allow bacteria to
survive unfavorable environmental conditions.
11. How do bacteria reproduce asexually?
ANSWER ✓ Through binary fission, where a single cell divides into two genetically
identical daughter cells.
12. What is conjugation in bacteria?
ANSWER ✓ A process where genetic material is transferred between bacterial cells
through direct contact via a pilus.
13. What are extremophiles?
ANSWER ✓ Organisms, primarily archaea, that thrive in extreme environments (high
temperature, salinity, acidity, etc.).
14. What distinguishes gram-positive from gram-negative bacteria?
ANSWER ✓ Gram-positive bacteria have a thick peptidoglycan layer that retains crystal
violet stain, while gram-negative have a thin peptidoglycan layer and an outer
membrane that doesn't retain the stain.
15. What are cyanobacteria?
ANSWER ✓ Photosynthetic bacteria that produce oxygen and were responsible for the
Great Oxygenation Event in Earth's history.
Unit 3: Protists
16. Why are protists considered a "paraphyletic" group?
ANSWER ✓ Because they include some but not all descendants of a common ancestor;
they're defined more by what they're not (not plants, animals, or fungi) than by shared
characteristics.
17. What are the three main nutritional strategies of protists?
ANSWER ✓ Photoautotrophs (algae), heterotrophs (protozoa), and mixotrophs
(combining both strategies).
18. What is the difference between plasmodial and cellular slime molds?
ANSWER ✓ Plasmodial slime molds form a multinucleate mass (plasmodium), while
cellular slime molds exist as individual cells that aggregate when food is scarce.
Unit 1: Introduction to Biological Diversity
1. What is biodiversity?
ANSWER ✓ Biodiversity refers to the variety of life at all levels of biological organization,
including genetic diversity, species diversity, and ecosystem diversity.
2. What are the three main levels of biodiversity?
ANSWER ✓ Genetic diversity (variation within species), species diversity (variety of
species in an area), and ecosystem diversity (variety of habitats and ecological
processes).
3. Who developed the binomial nomenclature system?
ANSWER ✓ Carl Linnaeus developed the binomial nomenclature system for naming
species using genus and species names.
4. What is the correct format for writing a scientific name?
ANSWER ✓ Genus capitalized, species lowercase, both italicized (or underlined if
handwritten), e.g., Homo sapiens.
5. What are the three domains of life?
ANSWER ✓ Bacteria, Archaea, and Eukarya.
6. What distinguishes prokaryotes from eukaryotes?
ANSWER ✓ Prokaryotes lack membrane-bound organelles and a true nucleus, while
eukaryotes have both.
7. What are the key characteristics of the domain Archaea?
ANSWER ✓ Extremophiles often living in harsh environments, distinct cell membrane
composition, and genetic machinery more similar to eukaryotes than bacteria.
8. What is the difference between an autotroph and a heterotroph?
ANSWER ✓ Autotrophs produce their own food (e.g., through photosynthesis), while
heterotrophs consume other organisms for nutrition.
Unit 2: Prokaryotes - Bacteria and Archaea
9. What are the three common shapes of bacterial cells?
ANSWER ✓ Cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped).
, 10. What is the function of bacterial endospores?
ANSWER ✓ Endospores are dormant, highly resistant structures that allow bacteria to
survive unfavorable environmental conditions.
11. How do bacteria reproduce asexually?
ANSWER ✓ Through binary fission, where a single cell divides into two genetically
identical daughter cells.
12. What is conjugation in bacteria?
ANSWER ✓ A process where genetic material is transferred between bacterial cells
through direct contact via a pilus.
13. What are extremophiles?
ANSWER ✓ Organisms, primarily archaea, that thrive in extreme environments (high
temperature, salinity, acidity, etc.).
14. What distinguishes gram-positive from gram-negative bacteria?
ANSWER ✓ Gram-positive bacteria have a thick peptidoglycan layer that retains crystal
violet stain, while gram-negative have a thin peptidoglycan layer and an outer
membrane that doesn't retain the stain.
15. What are cyanobacteria?
ANSWER ✓ Photosynthetic bacteria that produce oxygen and were responsible for the
Great Oxygenation Event in Earth's history.
Unit 3: Protists
16. Why are protists considered a "paraphyletic" group?
ANSWER ✓ Because they include some but not all descendants of a common ancestor;
they're defined more by what they're not (not plants, animals, or fungi) than by shared
characteristics.
17. What are the three main nutritional strategies of protists?
ANSWER ✓ Photoautotrophs (algae), heterotrophs (protozoa), and mixotrophs
(combining both strategies).
18. What is the difference between plasmodial and cellular slime molds?
ANSWER ✓ Plasmodial slime molds form a multinucleate mass (plasmodium), while
cellular slime molds exist as individual cells that aggregate when food is scarce.
