Download Animal Systems I

Name
Class
Date
Animal
Systems I
Structure and Function
Q: How do the structures of animals allow them to obtain essential materials
and eliminate wastes?
WHAT I KNOW
27.1 How do
different animals
obtain and digest
food?
27.2 How do
animals in different
environments
breathe?
27.3 How have
animals evolved
complex, efficient
ways to move
materials through
their bodies?
27.4 How do
animals in different
environments excrete
metabolic wastes?
WHAT I LEARNED
SAMPLE ANSWER:
Most animals
have mouths and digestive
tracts.
Some
invertebrates break down
food through intracellular
digestion, but many animals
use extracellular digestion.
SAMPLE ANSWER:
Animals need
oxygen. Some animals obtain
oxygen with gills. Others
obtain oxygen with lungs.
SAMPLE ANSWER: Many aquatic
animals exchange gases
through gills. Respiratory
structures in terrestrial
animals include skin, mantle
cavities, book lungs, tracheal
tubes, and lungs.
SAMPLE ANSWER:
Blood moves
materials through an
animal’s body.
SAMPLE ANSWER: Most vertebrates
with gills have a single-loop
circulatory system. Most
vertebrates that use lungs for
respiration have a double-loop
circulatory system.
SAMPLE ANSWER:
SAMPLE ANSWER: Aquatic animals
allow ammonia to diffuse
out of their bodies into
surrounding water. Some
terrestrial invertebrates
produce urine in nephridia.
Other terrestrial invertebrates
convert ammonia into uric
acid. Mammals and land
amphibians convert ammonia
into urea.
Animal wastes
are removed by the excretory
system.
SAMPLE ANSWER:
Chapter 27 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
421
Name
Class
Date
27.1 Feeding and Digestion
Lesson Objectives
Describe the different ways animals get food.
Explain how digestion occurs in different animals.
Describe how mouthparts are adapted for an animal’s diet.
Lesson Summary
Obtaining Food Animals obtain food in different ways.
▶ Most filter feeders catch algae and small animals by using modified gills or other
structures as nets that filter food items out of water.
▶ Detritivores feed on detritus, or decaying bits of plant and animal material. Detritivores
often obtain extra nutrients from the bacteria, algae, and other microorganisms that grow
on and around the detritus.
▶ Carnivores eat other animals.
▶ Herbivores eat plants or parts of plants in terrestrial and aquatic habitats.
▶ Many animals rely upon symbiosis for their nutritional needs. Parasites live within or
on a host organism, where they feed on tissues or on blood and other body fluids. In
mutualistic relationships, both participants benefit.
Processing Food Some invertebrates break down food primarily by intracellular digestion,
but many animals use extracellular digestion to break down food.
▶ In intracellular digestion, food is digested inside specialized cells that pass nutrients to
other cells by diffusion.
▶ In extracellular digestion, food is broken down outside cells in a digestive system and
then absorbed.
• Some invertebrates, such as cnidarians, have a gastrovascular cavity with a single
opening through which they both ingest food and expel wastes.
• Many invertebrates and all vertebrates, such as birds, digest food in a tube called a
digestive tract, which has two openings: a mouth and an anus. Food travels in one
direction through the digestive tract.
Specializations for Different Diets The mouthparts and digestive systems of animals
have evolved many adaptations to the physical and chemical characteristics of different foods.
▶ Carnivores typically have sharp mouthparts or other structures that can capture food,
hold it, and “slice and dice” it into small pieces.
▶ Herbivores typically have mouthparts adapted to rasping or grinding.
▶ Some animals have specialized digestive organs that help them break down certain foods.
For example, cattle have a pouchlike extension of their stomach called a rumen, in which
symbiotic bacteria digest cellulose.
Lesson 27.1 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
422
Name
Class
Date
Obtaining Food
1. Complete the table about types of feeders.
Types of Feeders
Type of Feeder
Description
Filter feeder
filters food items out of water
Detritivore
feeds on decaying bits of plant and animal material
Carnivore
eats other animals
Herbivore
eats plants or parts of plants
Parasitic
symbionts
live within or on a host organism, where they feed on tissues or
on blood and other body fluids
Mutualistic
symbionts
live within or on a host organism and gain their nutrition in
such a way that they do not harm the host
2. Explain the difference between a parasite and a host.
A parasite lives within or on a host organism and feeds on that host organism. The
host is usually harmed by the feeding behavior of the parasite.
3. Give an example of a mutualistic relationship involving a nutritional symbiont.
Some kinds of coral and algae have a mutualistic relationship. The algae produce
food for the coral through photosynthesis. In return, the algae use some of the coral’s
waste products as nutrients.
Processing Food
4. How is the digestion of food different in simple animals compared with more complex
animals?
Simple animals break down food primarily through intracellular digestion, but more
complex animals use extracellular digestion. Also, simple animals have a gastrovascular cavity through which food enters and wastes are expelled. More complex animals
have a one-way digestive tract through which food moves.
5. How is a one-way digestive track like a “disassembly line”?
Food is broken down one step at a time through mechanical and chemical digestion.
Lesson 27.1 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
423
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Class
Date
6. Label the digestive structures of this cnidarian.
Mouth/Anus
Gastrovascular
cavity
Specializations for Different Diets
7.
Carnivore
Herbivore
The visual analogy compares different types of teeth with common tools. Complete the
table about the different kinds of teeth found in mammals and the tools they are like.
Teeth Adaptations in Mammals
Type of Teeth
Description
Tool Analogy
Canines
pointed teeth used for piercing, gripping, and tearing
fork
Incisors
chisel-like teeth used for cutting, gnawing, and grooming
nail clippers
Molars
flat teeth used for grinding food
pieces of
sandpaper
8. Explain whether organisms with a gastrovacular cavity or organisms with a digestive tract
obtain and process nutrients more efficiently.
SAMPLE ANSWER:
Organisms with digestive tracts obtain and process nutrients more
efficiently. They are able to take in nutrients and excrete wastes at the same time
because their mouth and anus are separate orifices.
Lesson 27.1 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
424
Name
Class
Date
27.2 Respiration
Lesson Objectives
Describe the characteristics of respiratory structures that all animals share.
Explain how aquatic animals breathe.
Identify the respiratory structures that enable land animals to breathe.
Lesson Summary
Gas Exchange Animals have evolved respiratory structures that promote the movement
of oxygen and carbon dioxide in the required directions by passive diffusion.
▶ Gases diffuse most efficiently across a thin, moist membrane.
▶ Respiratory structures maintain a difference in concentrations of oxygen and carbon
dioxide on either side of the respiratory membrane, promoting diffusion.
Respiratory Surfaces of Aquatic Animals Many aquatic invertebrates and most
aquatic chordates, other than reptiles and mammals, exchange gases through gills.
▶ Gills are feathery structures that expose a large surface area of thin, selectively permeable
membrane to water.
▶ Aquatic reptiles and aquatic mammals, such as whales, breathe with lungs, organs that
exchange oxygen and carbon dioxide, and must hold their breath underwater.
Respiratory Surfaces of Terrestrial Animals Terrestrial animals must keep their respiratory membranes moist in dry environments.
▶ Respiratory structures in terrestrial invertebrates include skin, mantle cavities, book lungs,
and tracheal tubes.
▶ All terrestrial vertebrates breathe with lungs.
• In mammalian lungs, alveoli provide a large surface for gas exchange.
• In birds, a unique system of tubes and air sacs enables one-way airflow.
Gas Exchange
For Questions 1–5, write True if the statement is true. If the statement is false, change the
underlined word or words to make the statement true.
passive
1. In respiratory systems, gas exchange occurs through active diffusion.
True
2. Substances diffuse from an area of higher concentration to an area of
lower concentration.
moist
3. Gases diffuse most efficiently across thin, dry surfaces.
True
4. Respiratory structures have a selectively permeable membrane.
carbon dioxide
5. Respiratory structures maintain a difference in the relative
concentrations of oxygen and nitrogen on either side of the
membrane.
Lesson 27.2 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
425
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Class
Date
6. Respiratory organs have large surface areas. How is this an advantage to an animal?
The more surface area that is exposed to the environment, the greater the amount of
gas exchange that can occur.
7. Respiratory surfaces are moist. How does this enable respiration to take place?
Gases diffuse most efficiently across a moist membrane.
Respiratory Surfaces of Aquatic Animals
8. Complete the flowchart that describes the path of water as it moves through fish.
mouth
Water flows in through the fish’s ________________,
where muscles pump the
gills
water across the ________________.
oxygen
As water passes over the gill filaments, the filaments absorb ________________
carbon dioxide
from water and release ________________.
operculum
Water and carbon dioxide are pumped out behind the ________________.
Respiratory Surfaces of Terrestrial Animals
9.
Label the book lung, spiracles, and tracheal tubes in the organisms
below. Write a description of these structures on the lines below the organisms.
Grasshopper
Spider
tracheal tubes
Airflow
spiracles
book lung
Book lungs are made of parallel, sheet-
Tracheal tubes extend throughout the
like layers of thin tissues that contain
body. Air enters and leaves the system
blood vessels.
through openings called spiracles.
Lesson 27.2 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
426
Name
Class
10.
Date
Label the nostrils, mouth, and throat; trachea; and lungs of the
animals below.
Nostrils, mouth,
and throat
Trachea
Trachea
Nostrils,mouth,
and throat
Lung
Lung
Amphibian
Reptile
Nostrils,
mouth,
and throat
Trachea
Mammal
Lung
11. Describe the basic process of breathing among land vertebrates.
Inhaling brings oxygen-rich air through the trachea into the lungs. The oxygen diffuses into the blood, and carbon dioxide diffuses out of the capillaries into the air.
Oxygen-poor air is then exhaled.
12. Why are the lungs of birds more efficient than those of most other animals?
Air flows through bird lungs in only one direction. Thus, gas exchange surfaces are
continuously in contact with oxygen-rich air.
13. Compare the structure and function of fish gills with the structure and function of bird lungs.
Both fish gills and bird lungs function to receive a constant supply of oxygen. The
structure of fish gills allows this one-way flow by pumping water through the mouth,
over the gill filaments, and out the operculum as a fish swims. A unique system of
tubes allows the one-way flow of oxygen in bird lungs.
Lesson 27.2 • Workbook A • Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
427