& GEOLOGY CONTENTS 1. The plant kingdom 1.1. It is an animal 1.2. Animal classification 1.3. Vertebrates: mammals 1 st ESO IES Marqués de Comares
1. THE ANIMAL KINGDOM 1.1. It is an animal From microscopic worms to giant whales, the animal kingdom includes an amazing variety of living things, but all of them have certain characteristics in common. Figure 1. These organisms look like plants, but they re one of the many plantlike animals that can be found growing on shipwrecks and other underwater surfaces. What makes the animals in figure 1 different from plants? Is it because animals eat other living things? Is this enough information to identify them as animals? What characteristics do animals have? 1. Animals are pluricellulars, they are made of many cells. 2. Animal cells are eukaryotic, they have a nucleus and specialized structures inside the cells called organelles. 3. Animals are heterotrophs, they depend on other living things in the environment for food. Some eat plants, some eat other animals, and some eat plants and animals. 4. Mostly animals move from place to place. They can escape from their enemies and find food, mates, and places to live. Animals that move slowly or not at all adapt to their environment can take care of these needs in other ways. 5. All animals are capable of reproducing sexually. Some animals can also reproduce asexually. 4.1
1.2. Animal classification Scientists have identified and named more than 1.8 million species of animals. It is estimated that there are another 3 million to 30 million more to identify and name. Animals can be classified into two major groups, as shown in figure 2. Figure 2. Animals can be classified into two large groups. These groups can be broken down further based on different animals characteristics. All animals have common characteristics, but animals in the same group have characteristics that are more similar because all the members of a group probably descended from a common ancestor. When a scientist finds a new animal, how does he or she begin to classify it? To classify an animal, a scientist first looks to see whether or not the animal has a backbone. Animals with backbones are called vertebrates Their backbones are made up of a stack of structures called vertebrae that support the animal. The backbone also protects and covers the spinal cord a bundle of nerves that is connected to the brain. The spinal cord carries messages to all other parts of the body. It also carries messages from other parts of the body to the brain. Examples of vertebrates include fish, frogs, snakes, birds, and humans. Animals without a backbone are classified as invertebrates About 97 percent of all animal species are invertebrates. Sponges, jellyfish, worms, insects, and clams are examples of invertebrates. Many invertebrates are well protected by their outer coverings. Some have shells, some have a skeleton on the outside of their body, and others have a spiny outer covering. 4.2
1.3. Vertebrates: mammals What is a Mammal? Mammals share a series of characteristics that distinguish their class: A body covered by hair. The birth of live young, and the feeding of newborns with milk produced by the females' mammary glands. All breathe through lungs, All possess a closed, double circulatory system and the most developed nervous systems in the animal kingdom. The ability to maintain a constant body temperature (homeothermy) has allowed them to spread out and conquer every corner of the Earth, from the coldest climates to hot deserts and from the mountains to oceans. Fig. 3. Body hair is unique to mammals and absent in other classes of animals. Sirenians, with little hair, and cetaceans are exceptions; in both cases, the absence of hair is a result of the mammal's adaptation to an aquatic environment. Dolphin Whale Manatee Dentition The majority of mammals change dentition in their passage to adulthood. Teeth are specialized for each function: molars for chewing, canines for tearing, and incisors for gnawing. In rodents such as chipmunks, the teeth are renewed by continuous growth. 4.3
Oviparous Mammals For a mammal to lay eggs seems improbable, but the surprising monotreme females, instead of giving birth to young, are oviparous. They are warm-blooded, have hair, and feed their newborn through mammary glands despite having no nipples. Platypuses seem like a cocktail of nature, inasmuch as parts of their bodies resemble those of other types of animal. The other monotremes, echidnas, are covered with spines, and their young grow in the mother's pouch. Fig. 4. Monotremes or oviparous mammals Platypus Echidna Efficient Nursery Marsupial females carry their newborn offspring in their marsupium, a pouch attached to their belly. The offspring are not very well developed when they come into the world after a gestation period that varies from two to five weeks. Upon emerging, the offspring must immediately climb with their front paws to the marsupium to survive. Once inside, they will be protected. They are continually supplied with milk through their mother's four teats, helping them complete their growth before leaving the pouch for the outside world. Fig. 5. Marsupial mammals Kangaroo Koala Bandico 4.4
VOCABULARY English Pronunciation Spanish Ancestor Animals Backbone ['bækbəʊn] Bandicoot Bird [bɜːd] [ ˈænsest ə(r)] Antepasado [ ˈænɪməls] Animales ['bændɪku:t] Columna vertebral Bandicoot Pájaro Cetacean [s ɪ'teɪʃjən] Cetáceo Chew [tʃu ː] Mascar Chordate [kɔːdeɪt] Cordado Clam [klæm] Almeja Class [klɑːs] Dentition [den'tɪʃən] Clase Dentición Dimorphism [dʌɪˈmɔːfɪk] Dimorfismo Dolphin [ ˈdɒlfɪn] Delfín Echidna [ ɪ'kɪdn ə] Equidna Embryo [ ˈembri əʊ] Embrión Family Feed [fiːd] [ ˈfæməli] Familia Alimentar Fertile [ ˈfɜːtaɪl] Fértil Fish [f ɪʃ] Frog [fr ɒɡ] Genus [ ˈdʒiːnəs] Gnaw [n ɔː] Hair [he ə(r)] Pez Rana Genero Roer Pelo Homeothermy [ ˌhəʊmi' əθɜːrmi] Homeotermo Insect [ ˈɪnsekt] Insecto Invertebrate [ ɪnˈvɜːtɪbrət] Invertebrado Jellyfish ['dʒelɪf ɪʃ] Medusa Kangaroo [ ˈkæŋɡəˈru ː] Canguro Kingdom [ ˈkɪŋdəm] Reino 4.5
Lung [lʌŋ] Pulmón Mammal [ ˈmæməl] Mamífero Manatee [ ˌmænəˈti ː] Manatí Marsupial [mɑːrˈsuːpiəl] Marsupial Monotreme ['mɒnətri:m] Nipple [ ˈnɪpəl] Monotrema Pezón Offspring [ ˈɒfsprɪŋ] Cría Order [ ˈɔːd ə(r)] Orden Oviparous [ əʊ'vɪpərəs] Ovíparo Phylum ['fɑɪləm] Filo Platypus [ ˈplætɪpəs] Ornitorrinco Shell Shelter [ ʃel] [ ˈʃelt ə(r)] Refugio Concha - caparazón Sirenians [sʌɪˈriːnɪəns] Sirenios (orden de mamíferos) Skeleton Snake [sneɪk] [ ˈskelɪtn] Esqueleto Serpiente Species [ ˈspiːʃiːz] Especie Spinal cord [ ˈspaɪnl]/[kɔːd] Médula espinal Spiny [ ˈspaIni] Espinoso Sponge [spʌnd ʒ] Esponja Swear Tear [swe ə(r)] [te ə(r)] Tear [t ɪə(r)] Teeth [tiːθ] Tissue [ ˈtɪʃu ː] Sudor Rasgar Lágrima Dientes Tejido Vertebrate [ ˈvɜːtɪbrət] Vertebrado Whale [weɪl] Worm [wɜːm] Ballena Gusano 4.6