Transcript Living Things and the Environment

Review 8
Adaptations Review

 In your groups, answer the following questions
about your Arctic adaptation:
 1. Is the adaptation structural, behavioral or
physiological? Explain why.
 2. Why did that organism adapt that particular trait?
 3. How do you think that organism would be
different if it were in a desert instead of the Arctic?
Living things and the
environment

 Living things must be able to notice and react to
stimuli, such as sounds, chemicals, light or
temperature changes in its environment.
Thought Question 1
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 You and your friends decide to play basketball
because the Sun has come out. Describe the stimulus
and the response.
Types of stimuli in plants
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 Tropism: a plants response to stimuli such as
moisture, light or gravity
 Phototropism
 Gravitotropism
 Heliotropism
Phototropism
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 A plants response to light sources
Gravitotropism
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 The fact that all plants’ roots grow down and their
shoots grow up
 This is controlled by plant hormones called auxinsthey concentrate in the direction the plant should
grow
Heliotropism

 A plant adjusts its leaves throughout the day to catch
the Sun’s rays
Thought Question 2
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 During periods of droughts, plants need to conserve
their moisture. Would plants use heliotropism to
orient their leaves parallel or perpendicular to the
Sun’s rays? Explain your answer.
Stimulus and response
in animals

 Animals show more complex responses to stimuli
than plants do. Even bacteria show complexity.
 A taxis is a movement toward or away from a
stimulus.
 They’re different from plant tropism in that taxis
involve the movement of the whole organism , not
just part of it.
 Chemotaxis
Animal responses to
stimuli
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 Animals exhibit responses far more complex than a
tropism or taxis.
Thought question 3

 Perhaps you have seen an animal, such as a cat or an
owl, get around pretty well at night. What are two
differences in eye structure between typical
nocturnal animals and that of a human?
Research sensory
responses

 Use your laptops to research the following sensory organs or
structure. Fill in the type of sensory information that is collected, and
write a brief description about how that information is processed.
The first one has been completed for you:
 Eyes: Light, color, shades of black and white; light is focused onto
the retina, where rods and cones translate it into nerve impulses
 Ears:
 Tongue:
 Fingertips:
 Nose:
Homeostasis

 In addition to
monitoring the external
environment, an
organism’s body
constantly monitors
and maintains its
internal environment to
keep itself alert and
healthy.
Negative feedback
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 When your body senses a physiological change,
called negative feedback, it can stop the system from
moving in the direction it’s going
Innate responses
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 Innate behaviors are those that do not need to be
learned or taught. They are programmed within the
organism’s central nervous system.
 Examples:
 Taxis
 Reflex
Instincts

 More complex, innate animal behaviors triggered by
external stimuli.
Thought Question 4

 A colony of E. coli moves toward a source of sugar. A
pack of wolves sees one its members running with its
head raised and tail straight out, and the other
wolves begin to run toward the prey. In both cases,
animals moved toward a source of food. How was
the E. coli response different from the wolf pack
response?
Hidden instincts

 Some organisms release chemical messengers called
pheromones into their environments to
communicate with members of their own species.
Thought Questions 5 & 6

 Taxes, reflexes, and instincts all have the same
fundamental purpose. What is this purpose?
 Describe the major difference between a taxis and an
instinctive response.
Review

 Stimulus- external factor that affects an organism
 Tropism- Plant’s response to stimuli
 Taxis- Animal’s response to stimuli
 Reflex- nervous system reaction
 Instinct- more complex reaction to environment
Learned Behaviors
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 When things don’t come naturally, they must be
passed on from parents to their children through
learned behaviors
Conditioned responses
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 Some responses are learned, rather than innate.
Other complex animal
behaviors
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 Mating rituals
 Territoriality
 Schooling
Exit Ticket (Monday)

 What are some instinctual behaviors of humans?
 What are the least complex instincts called? What are
the most complex instincts called?
 Knowing how life developed, pose a theory about
how the complexity of instinctual behavior
developed over the history of the world, from plants
to humans.