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 - Definition: Consist of transforming food to obtain the nutrients it contains (molecules small enough to enter the cell). - Types of digestion in animals: - - INTRACELLULAR DIGESTION: - Animals without digestive system. - Digestion takes place inside the cells. - Eg: sponges. EXTRACELLULAR DIGESTION: - Animals with a digestive system. - 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) - Types of digestive systems: - Gastrovascular cavities. - 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: - 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: • • • • 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. • Nerve centers: process information (eg. Encephalon) • 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: • In invertebrates without an exoskeleton (eg. Earthworms): Muscles are in the outer wall of the body • 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