L1: LIFE ON EARTH

Question 1

What are the characteristics that define life?

Answer 1

-All living organisms are made of cells.
-DNA is used for reproduction and controlling cellular processes.
-Living things can maintain homeostasis (stable internal conditions).
-Organisms collect energy (e.g., photosynthesis, consuming other organisms).
-Living things sense and respond to their environment.
-Organisms evolve over time.

Question 2

What are the levels of biological organization?

Answer 2

Molecule → Cell → Tissue → Organ → Organ System → Individual Organism → Population → Community → Ecosystem → Biome → Biosphere.

Question 3

What is the flow of energy in ecosystems?

Answer 3

Energy flows from the sun → producers, → consumers.

Question 4

Are viruses considered alive? Why or why not?

Answer 4

No, viruses are not considered alive because they need a host cell to reproduce.

Question 5

What is systematics and how does it help understand evolutionary relationships?

Answer 5

Systematics is the science of classifying organisms and determining their relationships.

Question 6

How did Carolus Linnaeus contribute to the classification of life?

Answer 6

Linnaeus developed the hierarchical classification system

Question 7

What are the three domains of life?

Answer 7

Bacteria: Single-celled, no organelles, diverse environments.

Archaea: Single-celled, no organelles, often extremophiles.

Eukarya: Organisms with complex cells containing organelles (e.g., plants, animals, fungi).

Question 8

What is the difference between prokaryotic and eukaryotic cells?

Answer 8

Prokaryotic cells: Simple, lack organelles, no nucleus (e.g., bacteria, archaea).

Eukaryotic cells: Complex, have organelles like the nucleus, and specialized functions (e.g., plants, animals, fungi).

Question 9

What are the major kingdoms of life? (6)

Answer 9

Bacteria:
Archaea:
Protista:
Plantae:
Fungi:
Animalia:

Question 10

What is the difference between gymnosperms and angiosperms?

Answer 10

Gymnosperms: Seed-producing plants (e.g., conifers, pine trees).

Angiosperms: Flowering plants, the most diverse group, with flowers for reproduction and fruits to attract animals for seed dispersal.

Question 11

What are fungi and their role in ecosystems? How do they reproduce? Examples?

Answer 11

Fungi are decomposers, breaking down organic matter and absorbing nutrients.
They reproduce using spores.
Includes mushrooms, moulds, and yeast.

Question 12

What is the difference between protostomes and deuterostomes?

Answer 12

Protostomes:
Mouth forms first during embryonic development.

Anus forms first, followed by the mouth during embryonic development.