Download 7.1: Adaptation and Variation

7.1: Adaptation and Variation
Adaptation: is a process that helps an organism survive and reproduce in a particular environment.
Organisms that survive long enough to reproduce have the opportunity to pass their genetic information
to their offspring.
Structural Adaptations: affects a specific part or feature of the organism’s body. For example – Human’s
opposable thumbs
Behavioural Adaptations: affect the way an organism acts. Behavioural adaptations can include hunting
strategies, migration, hibernation, and other behaviours that help an organism survive in a particular
environment.
Physiological Adaptations: permit an organism to perform special functions.
Mimicry: is a special type of adaptation. It is a structural adaptation in which a harmless species
resembles a harmful species in coloration or structure. Predators that avoid the harmful species will also
avoid the mimic. (Monarch Butterfly and the Viceroy)
The Eastern Massasauga rattlesnake (Sistrurus catenatus catenatus) is Ontario’s only venomous snake,
has developed several adaptations that help it survive in its environment.
Structural Adaptations
-The dark, saddle-shaped
blotches on its brown to
greyish-brown body help the
snake blend into its
environment.
Behavioural Adaptations
- Snakes are ectothermic. The
snake uses the temperature of
its surrounding environment to
maintain an optimal body
temperature.
- The snake has a rattle at the
end of its tail to frighten
potential predators.
-The snake hibernates to avoid
freezing during the Ontario
winter.
Physiological Adaptations
- The snake injects venom into
its prey through two hollow
fangs. The venom is a
combination of hemotoxins and
cytotoxins. Hemotoxins attack
the blood and cause massive
hemorrhaging, (bleeding).
Cytotoxins attack the tissues,
making it easier for the snake to
digest its prey.
- The snake’s main diet is small
mammals. It uses a small hole
on each side if its head caked a
heat-sensitive pit to detect
warm-blooded animals up to 70
cm away, even in complete
darkness.
Learning Check:
1. What advantages does a fox snake get by mimicking rattlesnake behavior? [k/u]
2. Like most other snakes, rattlesnakes do not need to eat daily, and can go weeks or even months
without food. A rattlesnake re-absorbs a large part of the mass of its digestive tract in between feedings.
Once prey is consumed, the snake rebuilds its digestive system. This adaptation is relate to the
consumption of large, infrequent mails. [k/u, t/i]
a) What type of adaptation is this?
b) Why would this practice be advantageous to the rattlesnake?
3. A xerophyte describes a plant that has structural and physiological adaptations that enable it to
survive in areas with very little free moisture. One adaptation found in some xerophytes plants is the
ability to fold their leaves, especially during the day, reducing the rate of water loss by the plant.
What type of adaptation is this? [k/u]
4. The Eastern White Pine (Pinus strobus) is the provincial tree of Ontario. Eastern white pine is
moderately fire resistant. Mature trees survive most surface fires because they have thick bark, very few
branches on their trunks, and moderately deep root systems.
a) Identify the adaptations of the Eastern White Pine that would help this species of tree survive and be
successful in Ontario. [k/u]
b) What types of adaptations did you describe in Part a? [k/u]
5. Think of an animal or plant and identify the adaptations it has that help it survive and reproduce.
[app]