Download Sections 1.6-1.8

1.6-1.8 Warm-Up
1. What is a theory?
2. Explain natural selection.
3. What is an adaptation and how is it related to natural selection?
4. How does energy flow in an ecosystem?
5. How do nutrients move through an ecosystem?
1.6 Evolution explains the unity and diversity of life
What is a theory?
A theory in science is a comprehensive idea with broad explanatory
power
Why is Charles Darwin famous?
The Theory of Evolution by natural selection
This theory explains the diversity of life and underlying
commonalities among organisms
It is the central theme of Biology
When does evolution occur?
Evolution happens when populations of organisms with inherited
variations are exposed to environmental factors that favor the
success of some individuals over others
English Peppered Moth
How does evolution occur? What drives it?
The Theory of Natural Selection is the mechanism that allows
evolution to proceed
How does natural selection work?
natural selection is the ability to survive long enough to reproduce
the survivors have adaptations (inherited traits) that help them to
survive
these adaptations are passed down to their offspring
Natural Selection
(1) Population with varied inherited traits
(2) Elimination of individuals with certain traits
Figure 1.6B
(3) Reproduction of survivors
What adaptation helps these sea horses survive?
camouflage
Name some adaptations of the pangolin.
tough body armor with overlapping scales
a long tongue to flush termites and ants
out of their nests
What adaptations help the orca (a mammal) survive in the water?
breathes air from the top of its head through
nostrils
emits clicking sounds to communicate
uses echoes to locate obstacles and prey
1.7 Living organisms and their environments form
interconnecting webs
What is a food web?
a food web shows the interactions of organisms within an
ecosystem
it shows how energy flows through an ecosystem
Autotroph vs Heterotroph
an autotroph can make its own food through photosynthesis
a heterotroph needs to consume food (other animals or
plants) for energy and nutrients
Which organisms are the ultimate source of energy?
autotrophs (which include plants, some prokaryotes, and
some protists)
What are decomposers, and how do they fit into a
food web?
decomposers are prokaryotes, fungi, and small animals that feed on
dead organisms
they recycle dead organic matter into mineral nutrients that plants
can use
Matter vs Energy
BIOLOGY AND EVERYDAY LIFE
1.8 Connection: Biology is connected to our
lives in many ways
Can you name some current issues in society that relate to Biology?
Global Warming
Genetic Engineering
Medicine
Nutrition and Exercise
Endangered Species
Pollution
What is technology?
Technology is the application of scientific knowledge
Many technological advances stem from the scientific study of
life
Homework
Packet Exercises 5-7