ANIMALS
1. THE CHARACTERISTICS OF ANIMALS
1.1. What are animals like?
• Wide variety of:
•
•
•
•
•
Shapes
Sizes
Structures
Behaviours
Environments
• Eukaryotic
• Multicellular
• With organs (even systems)
• Their bodies are symmetrical: Symmetry
Bilateral
Radial
SYMMETRY
1.2. Vital functions
• NUTRITION: They are heterotrophic.
• INTERACTION:
• They can move.
• They have: - locomotor system
- nervous system
- sense organs (cephalisation)
• REPRODUCTION: They reproduce sexually (although some can also reproduce
asexually)
1.3. Classification (the main animal groups)
• INVERTEBRATES:
They don´t have:
a vertebral column
an internal skeleton
• VERTEBRATES:
They have:
bilateral symmetry
a vertebral column
an internal skeleton
2) NUTRITION (1): OBTAINING NUTRIENTS
Tentacles
2.1. Feeding:
- Taking in food.
- Structures:
Tongue
Chelicerae
Beak
Teeth
2.2. Digestion
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Definition: Consist of transforming food to obtain the nutrients it
contains (molecules small enough to enter the cell).
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Types of digestion in animals:
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INTRACELLULAR DIGESTION:
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Animals without digestive system.
-
Digestion takes place inside the cells.
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Eg: sponges.
EXTRACELLULAR DIGESTION:
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Animals with a digestive system.
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Digestion takes place outside the cells.
- EXTRACELLULAR DIGESTION (Animals with a digestive system)
- Processes:
1) DIGESTION: Food → nutrients.
2) The nutrients are ABSORBED and transported to the cells (by
the circulatory system).
3) Undigested food → ELIMINATED (feces)
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Types of digestive systems:
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Gastrovascular cavities.
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Digestive tracts.
ACTIVITIES:
- Copy the outlines on page 59 and write two examples of each type of animal.
- Why is it necessary the digestion of food?
- How do the nutrients obtained in digestion reach the cells?
- What happens to indigested food?
- Tell the differences between gastrovascular cavities and digestive tracts.
- Activity 3 on page 76 (parts of a digestive tract).
3) NUTRITION (2): RESPIRATION
- Respiration: gas exchange with the external
environment:
- Taking in O2: necessary to cellular
respiration.
- Expelling CO2: produced by cellular
respiration.
- Animals have specialised body parts for carrying
out gas exchange:
- Animals that obtain O2 from water:
through the skin or gills.
- Animals that obtain O2 from air: through
tracheae or lungs.
MITOCHONDRION
Animals in which gas exchange takes place through
THE SKIN:
- In animals that live in water or in very moist land environments.
- Types of animals with this kind of respiration:
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Sponges
Cnidarians
Worms
Some amphibians
Animals in which gas exchange takes place through
GILLS:
- In aquatic animals.
- Gills consist of sheets-like structures or filaments covered in a very thin skin and
full of blood vessels.
- Types of animals with this kind of respiration:
- Fish
- Crustaceans
- Aquatic molluscs
- Some amphibians
Animals in which gas exchange takes place through
TRACHEAE:
- Tracheae are very thin tubes, with openings called
spiracles, that branch out to reach the tissues.
- Types of animals with this kind of respiration: INSECTS
Animals in which gas exchange takes place through
LUNGS:
- Lungs are two sponge-like organs, made up of million of
cavities ( alveoli ) with thin walls covered in blood vessels.
- Types of animals with this kind of respiration:
- Amphibians
- Reptiles
- Birds
- Mammals
4) NUTRITION : CIRCULATION AND EXCRETION
4.1. CIRCULATION
- Aim: transporting substances to the cells.
- Types of animals:
- With no circulatory system:
- Sponges and cnidarians (jellyfish and polyps).
- Their cells exchange substances with the environment directly.
- With circulatory system
CIRCULATORY SYSTEM:
- PARTS →It Is made up of:
• Circulatory fluid (or liquid) (eg. Blood).
• Tubes called vessels.
• A pumping mechanism (a heart).
- Types of circulatory systems:
- Open circulatory system.
- Closed circulatory system.
OPEN CIRCULATORY SYSTEM
- Circulating fluid (blood) →
• It is able to move in and out of the vessels.
• It bathes the tissues
- Types of animals →
- ARTHROPODS.
- MOLLUSCS.
CLOSED CIRCULATORY SYSTEM
- Circulating fluid (blood) → Never leaves the inside of the vessels
- Types of animals →
- VERTEBRATES.
- Some invertebrates, such as annelids.
4.2. EXCRETION
- Aim: expelling waste products.
- Types of animals:
- Animals that don´t have specialised body parts for carrying out excretion:
- Sponges and cnidarians (jellyfish and polyps).
- They eliminate waste through the Surface of their bodies.
- Animals that eliminate waste through specialised
structures:
- They pick up waste from fluids (such as blood)
inside the bodies.
- The organs that carry out excretion are:
- RESPIRATORY ORGANS:
- They remove CO2 from celular respiration:
- CO2 BLOOD → external environment.
- EXCRETORY ORGANS:
- They filter the blood, pick up any waste and
expel it (eg. Through urine).
- Eg. Kidneys in vertebrates.
CIRCULATORY SYSTEMS
Heart
Carry O2 and nutrients
to the cells
OPEN CIRCULATORY
SYSTEM
FUNCTION
Found in
- Some invertebrates
- All vertebrates
PARTS
Found in:
- Arthropods
- Molluscs
Vessels
Circulating fluid
CLOSED CIRCULATORY
SYSTEM
Remove CO2 and other
wastes from the cells
TYPES
CIRCULATORY SYSTEMS
Heart
Carry O2 and nutrients
to the cells
OPEN CIRCULATORY
SYSTEM
FUNCTION
Found in
- Some invertebrates
- All vertebrates
PARTS
Found in:
- Arthropods
- Molluscs
Vessels
Circulating fluid
CLOSED CIRCULATORY
SYSTEM
Remove CO2 and other
wastes from the cells
TYPES
5) INTERACTION IN ANIMALS: RECEPTORS
SENSE ORGANS:
• DEFINITION: They are receptors which perceive a specific type of stimulus.
• TYPES:
• PHOTORECEPTOR ORGANS: they perceive light
• MECHANORRECEPTOR ORGANS: they perceive:
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Vibrations
Position of the body
movement
Pressure
• CHEMORECEPTOR ORGANS: they perceive chemical substances.
PHOTORECEPTOR ORGANS
• They perceive LIGHT: so the enable the sense of SIGHT
• TYPES:
• SIMPLE EYES: in many invertebrates
• COMPOUND EYES: in ARTHROPODS (such as insects)
• CAMERA-TYPE EYES: In some invertebrates (eg. Cephalopods)
In all vertebrates.
MECHANORECEPTOR ORGANS
- TYPES depending on the stimulus perceived:
• HEARING ORGANS:they perceive vibrations in the air or water.
they enable the sense of HEARING
• BALANCE ORGANS: They provide information about position and
movement of the body
• LATERAL LINE (In fish): Detect vibrations and movement
• SKIN: perceives pressure, so it enables the sense of TOUCH.
CHEMORRECEPTOR ORGANS
• They perceive chemical substances present in air, water, or food.
• They enable the senses of SMELL and TASTE.
• They are located in the head, near the mouth.
• EXAMPLES:
•
ANTENNAE: in arthropods.
•
TONGUE
•
NASSAL PASSAGES
VERTEBRATES
TUBERS
6) INTERACTION IN ANIMALS:
COORDINATION
Animals have two coordination systems:
the nervous system and the endrocrine
system.
NERVOUS SYSTEM
- FUNCTIONS:
• Receiving the information
perceived by the sense organs.
• Interperting it and generating
orders (responses).
• Sending these orders to the
effectors.
NERVOUS SYSTEM
• It is made up of cells called NEURONS.
• NEURONS:
• They are connected to each other forming a communications network.
• They transmit information by means of electrical signals called nerve impulses.
- TYPES OF NERVOUS SYTEMS:
1. Network of nerves: in simple animals (eg. jellyfish, polip)
2. Nerve centers and nerves: in more complex animals.
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Nerve centers: process information (eg. Encephalon)
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Nerves: connect nerve centers with
- sense organs
- effectors
ENDOCRINE SYSTEM
- It is made up of organs called ENDOCRINE GLANDS.
- The information is transmitted by means of
substances called HORMONES:
• They travel through the blood.
• They trigger responses in effectors.
₋ EXAMPLES OF RESPONSES coordinated through
hormones:
• Metamorphosis in arthropods.
• Reproduction cycles.
• Growth.
ACTIVITY: Comparison
between the nervous and
endocrine systems
Type of cells/ organs
involved:
Type of signals they
produce:
How do signals “travel”?
Type of processes they
coordinate:
COORDINATION SYSTEMS
NERVOUS SYSTEM
ENDOCRINE SYSTEM
ACTIVITY: Comparison
between the nervous and
endocrine systems
TYPE OF CELLS/ ORGANS
INVOLVED:
TYPE OF SIGNALS THEY
PRODUCE:
HOW DO SIGNALS
“TRAVEL”?
TYPE OF PROCESSES
THEY COORDINATE:
COORDINATION SYSTEMS
NERVOUS SYSTEM
ENDOCRINE SYSTEM
Neurons (cells)
Endocrine gland (organ)
Nerve impulses
(electrical signals)
Substances called
hormones
The impulses travel
through nerves (they are
made up of neurons)
Hormones travel through
the blood
Movements
Reproduction, growth,
metamorphosis
7) INTERACCION: EFECTORS
- Effectors carry out two main types of responses:
- 1. Movement.
- 2. Secretion of substances.
- MOVEMENT:
- Is enabled by the action of MUSCLES. They generate
movement when they contract.
- Actions of the muscles:
- Movement of the internal organs (eg. the heart)
- Changes in the posture or position of the body
(these muscles belong to the locomotor system)
- Examples of muscles belonging to the locomotor system:
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In invertebrates without an exoskeleton (eg. Earthworms):
Muscles are in the outer wall of the body
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In vertebrates with an exoskeleton (eg. Insects):
Muscles are attached to the inside of the exoskeleton
•
In vertebrates:
Muscles are attached to the internal skeleton
- SECRETION OF SUBSTANCES
- Secretion: production of substances and their discharge.
- These substances are produced by organs called glands.
- Examples:
- Poison (in the skin of some amphibians)
- Milk (in mammals)
- FRUITS:
- The fruit develops from the ovary.
- PURPOSE OF A FRUIT:
- To protect the seeds.
- To help with the dispersion of the seeds.
- TYPES OF FRUITS:
- Fleshy fruits.
- Nuts.
6.5. Seed dispersión and germination
- Seeds are dispersed by the wind, by animals...
- Dispersion methods of fruits and seeds:
- By propulsion.
- By wind.
- By animals.
- By water.
- When the seeds fall to the ground (if conditions are favourable) germination occurs.
- GERMINATION:
- The seed absorbs water.
- The seed opens up.
- The embryo begins to develop a new plant.
7. CLASSIFICATION OF PLANTS
PLANTS
Plants with seeds
Plants
without seeds
MOSSES
SPERMATOPHYTES
FERNS
GYMNOSPERMES
ANGIOSPERMES
PINE (pino)
FIR (abeto)
CYPRESS
(ciprés)
9.2. Plants and the environment
- Thanks to PHOTOSYNTHESIS, plants:
- Provide the atmosphere with oxygen.
- Reduce the excess of CO2 in the
atmosphere.
- Provide the heterotrophic living
beings with organic nutrients.
Label the parts
of your flower
and write the
function of each
of them