history of life

Question 1

L.O: ORIGINS OF LIFE— explain how life began on Earth & identify key evolutionary milestones, including the RNA World hypothesis & major biological events

Answer 1

• Earth formed 4.6 billion years ago
• Early Earth (Primordial Soup); life began when Organic molecules formed in Earth’s early oceans, as demonstrated by the Miller-Urey experiment.
• RNA predated DNA & proteins as it was the first self-replicating molecule

The earliest life forms were prokaryotes, simple single-celled organisms without a nucleus.

Question 2

L.O: DIVERSITY OF LIFE— define biodiversity, explore its levels & examine Canada’s unique ecosystems & the threats they face

Answer 2

• Biodiversity:

Question 3

L.O: TAXONOMY- understand the hierarchical classification system & its role in organizing biodiversity & guiding conservation efforts

Question 4

L.O: PHYLOGENETIC TREES— interpret phylogenetic trees to understand evolutionary relationships using data from genetics, morphology & fossils

Question 5

when was Earth formed

Answer 5

4.6 billion years ago, through the assembly of an organic molecules

Question 6

when was life likely originated

Answer 6

3.5 to 4 billion years ago in ancient oceans.

Question 7

earth had key chemical ingredients that allowed life to start

Answer 7

methane
ammonia
water
hydrogen

Question 8

abiogenesis

Answer 8

process of life arising from non-living matter like macromolecules

Question 9

THE MILLER-UREY EXPERIMENT (1950S)

Answer 9

electric discharges
produced amino acids, nucleotides & other building blocks of life

Question 10

DNA __________ proteins
proteins ________ ______

Answer 10

DNA encodes proteins
proteins catalyze DNA replication

Question 11

how was RNA molecules formed?

Answer 11

early RNA molecules formed through the polymerization of ribonucleotides

Question 12

WHAT’S THE RNA WORLD HYPOTHESIS

Answer 12

• RNA predated DNA and proteins as the first self-replicating molecule, kickstarting evolution
  through natural selection
• RNA molecules were crucial in the early stages of life because they could store genetic information and catalyze chemical reactions (acting as ribozymes).

Question 13

THE EARLY EARTH (PRIMORDIAL SOUP)

Answer 13

a high-energy
environment rich in simple molecules.

methane, ammonia, water, and hydrogen played a role in making these organic compounds

Question 14

KEY FEATURES OF RNA

Answer 14

1. stores genetic information (sequence of bases: A,C,G, U)
2. acts as a catalyst, forming new RNA molecules
3. natural selection favoured RNA molecules with improved catalytic abilities

Question 15

RNA to DNA to proteins (CHECK CHAT)

Answer 15

RNA speeding up, ribosomes catalyzing replication, formations of polypeptides chains of amino acids,

Question 16

DNA key points

Answer 16

• DNA is more stable than RNA
  making the primary genetic material
• cell membranes (phospholipids) formed
  compartments, enclosing RNA & proteins
• these innovations paved the way for modern cells

Question 17

CYANOBACTERIA EVOLVED ______ ABOUT ___billion years ago

Answer 17

photosynthesis, 2.5 billion years ago

Question 18

CYANOBACTERIA’S OXYGEN PRODUCTION ….

Answer 18

transformed earth, enabling more complex life

Question 19

When did the Cambrian explosion occur?

Answer 19

540 million years ago

Question 20

plants and fungi colonized land about ….

Answer 20

500 million years ago

Question 21

WHAT IS BIODIVERSITY?

Answer 21

• refers to the assortment of living things within an ecosystem, whether were looking at the whole planet or given area

BIODIVERSITY encompasses GENETIC DIVERSITY, SPECIES
DIVERSITY & ECOSYSTEM DIVERSITY

the evolutionary process shapes biodiversity

Question 22

WHY DOES BIODIVERSITY MATTER?

Answer 22

ECOSYSTEM SERVICES— pollination, water purification, carbon
sequestration

biodiversity ENHANCES RESILIENCE TO ENVIRONMENTAL
CHANGES

CULTURAL & ECONOMIC BENEFITS— ecotourism, medicines, food
security

Question 23

BIODIVERSITY UNDER THREAT what are the main threats and impact

Answer 23

• MAIN THREATS:
  habitat
  destruction
  climate change
  invasive species
  pollution
• IMPACT— Extinction reduces
  genetic diversity and disrupts
  ecosystems
• were experiencing the 6th mass extinction

Question 24

WHAT IS TAXONOMY?

Answer 24

the science of naming, describing &
classifying organisms

critical for identifying & protecting biodiversity; helps identify & protect
endangered species

Question 25

HIERARCHICAL SYSTEM

Answer 25

Domain → Kingdom →
Phylum → Class → Order → Family → Genus → Species

(D.K.P.C.O.F.G.S)
Dear King Philip Came Over For Good Soup

Question 26

who’s the father of taxonomy, what did he introduce

Answer 26

Carl Linnaeus (1707-1778)
binomial nomenclature
- ex: humans - homo sapiens
polar bear - ursus maritimus

Question 27

WHAT ARE PHYLOGENETIC TREES

Answer 27

PHYLOGENETIC TREES are visual representations of EVOLUTIONARY HISTORY, showing
how species evolved from COMMON ANCESTORS THROUGH DIVERGENCE EVENT
they are built by GROUPING SPECIES BASED ON SHARED DERIVED
TRAITS & applying the PRINCIPLE OF PARSIMONY to minimize evolutionary assumption

Question 28

_____ define _____ ______, while _______
provide the _______ ______ _________

Answer 28

DERIVED TRAITS

EVOLUTIONARY RELATIONSHIPS

ANCESTRAL TRAITS

FOUNDATION FOR COMPARISON

Question 29

What are HOMOLOGOUS TRAITS

Answer 29

inherited from
a common ancestor (e.g., forelimb bones in mammals)

Question 30

CONVERGENT EVOLUTION

Answer 30

species evolve similar traits independently (e.g., wings in bats & birds)