Transcript Animals: Annelids and Insects

Warm-Up / EOC Prep
1.Which of the following adaptations allowed plants to
reproduce more successfully in dry environments?
A seeds
B sapwood
C root systems
D vascular tissue
2. The group of plants divided into monocots and dicots,
which are different flower structures, are
A angiosperms
B bryophytes
C conifers
D gymnosperms
Agenda
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Warm-up
Notes- Annelids and Insects
Annelid & Insect Worksheet
Life Cycle Drawings
Plant Booklet
Clean-Up
Cool-down
ANIMALS: ANNELIDS AND
INSECTS
Guided Notes 48
ANNELIDS
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Annelids are segmented worms. Nearly 70% of
all annelids live in the sea, and the other species
are mostly land earthworms. The size of
annelids can range from as small as 1 mm to as
big as 3 meters.
ANNELIDS
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Three large groups of annelids include marine
worms, earthworms, and leeches.
ANNELIDS
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Annelids are easily recognized by their segments,
which are visible as a series of ring-like
structures along their body. Each segment
contains digestive, excretory, circulatory, and
movement organs, but some segments are used
for specific functions (jobs)-such as reproduction,
feeding, or sensation, which means they are
specialized.
ANNELIDS
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The segments are separated by body walls called
septa. Nutrients and other materials pass
between the segments through their closed
circulatory system (blood).
ANNELIDS
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How do earthworms eat? They literally eat their
way through the soil and consume their body
weight in soil everyday. As they tunnel through
the soil they ingest soil. It travels down the
esophagus, into a storage organ called a crop
and then passed into the gizzard. The gizzard
grinds up the material and nutrients are absorbed
through the intestines.
ANNELIDS
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They have a simple
brain called a cerebral
ganglion. This brain is
then connected to a
nerve chord that runs
along the bottom of the
worm’s body. This
nerve cord connects
nerve centers in the
segments to the brain,
which allows the
delivery of sensory
information.
ANNELIDS
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Inside each segment there is fluid that creates a
hydrostatic skeleton that supports the segment.
Muscles in each segment then pull against this
skeleton. Alternating muscle contractions or pulls
cause the worm to move.
ANNELIDS
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Annelids also share another trait-setae. Setae are
bristles found on the outside of their body that
provide traction for crawling efficiently.
INSECTS
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Insects are the largest group of organisms on
Earth. There are more than 700,000 species, and
many scientists believe that millions more exist
but have not yet been discovered. In fact, 50%
of all animal species are insects.
INSECTS
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All insects share the same body plan made up of
3 sections:
INSECTS
1. Head: On the head are mandibles (jaws),
specialized mouthparts, and antennae. The
mandibles and mouth parts of different species
are different based on what they eat.
INSECTS
2. Thorax: The wings and three pairs of jointed
walking legs are attached to this middle section
made up of 3 fused segments.
INSECTS
3. Abdomen: The last section which is made up of
9-11 segments.
INSECTS
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Respiration: Most insects get oxygen through a
network of fine tubes called trachea. Oxygen
enters the body through holes called spiracles,
and air passes into the trachea, which delivers
oxygen to the rest of the body.
INSECTS
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Excretion: Insects conserve water and eliminate
waste with a system of excretory units called
malpighian tubules. Malpighian tubules are
fingerlike extensions from the gut that are bathed
in blood. Water and small particles move
through the tubules into the gut. Valuable
materials are reabsorbed into the bodily tissues
and the rest is excreted as waste.
INSECTS
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The insect life cycle can be very complex and
often several molts are required before the adult
stage can be reached. The dramatic physical
change that insects go through is called
metamorphosis, and there are two types.
INSECTS
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Complete
Metamorphosis:
EggLarvaPupa
Adult
INSECTS
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In complete metamorphosis the larva creates and
lives inside a capsule called a chrysalis. This is
called the pupa stage, and when it develops into
an adult it leaves the capsule. This type of
development is complex, but it can reduce
competition within species because the larvae
and adults use different habitats and food
sources!
INSECTS
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Incomplete
metamorphosis:
EggNymphAdult
INSECTS
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Incomplete metamorphosis is much less complex.
In this process the insect emerges from the egg
into a juvenile or nymph, that looks exactly like
the adult but smaller and without wings. After
several molts (shedding of the exoskeleton) the
nymph develops into an adult.
INSECTS
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Some insects live in social communities such as
bees and ants. They often live in highly
organized societies of genetically related
individuals and the role each member plays in
the community depends on heredity, diet,
hormones, and pheromones.
Leeches
Life Cycle Depictions
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Draw both incomplete and complete metamorphosis
life cycles.
 One
on each side of the notecard.
 Label both with the phase names.
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Underneath each, give a short description and an
insect that develops with that life cycle.
Page 729 if needed.
Cool-Down
1.
2.
The cerebral ganglion serves what purpose in
annelids?
What is the body plan that all insects share?