Chapter 1 Extended Characteristics of Living Organisms PDF

BY CELL :00201110983031 00201110983031 [email protected] CELL :00201110983031 00201110983031 [email protected]  Describe the characteristics of living organisms by describing: (a) movement as an action by an organism or part of an organism causing a c...

BY CELL :00201110983031 00201110983031 [email protected] CELL :00201110983031 00201110983031 [email protected]  Describe the characteristics of living organisms by describing: (a) movement as an action by an organism or part of an organism causing a change of position or place (b) respiration as the chemical reactions in cells that break down nutrient molecules and release energy for metabolism (c) sensitivity as the ability to detect and respond to changes in the internal or external environment (d) growth as a permanent increase in size and dry mass (e) reproduction as the processes that make more of the same kind of organism (f) excretion as the removal of the waste products of metabolism and substances in excess of requirements (g) nutrition as the taking in of materials for energy, growth and development CELL :00201110983031 00201110983031 [email protected]  MRSGREN RESPIRATION: Chemical reactions that break down nutrient molecules in living cells to release energy for metabolism. NUTRITION: Taking nutrients which are organic substances and minerals to be used in growth, tissue repair, development and production of energy EXCRETION: Removal of toxic materials, waste products of metabolism and substances in excess of requirements. Metabolism : means chemical reactions in cells including (respiration) GROWTH: Permanent increase in size and dry mass (dry mass means mass of the organism after removal of all its water content) by an increase in cell number or cell size or both. REPRODUCTION: The processes that make more of the same kind of organism. MOVEMENT (or locomotion): : An action by an organism or part of an organism causing a change of position or place. SENSITIVITY: the ability to sense or detect the change in the internal or external environment ( stimulus) and to take response. (Singular is stimulus) CELL :00201110983031 00201110983031 [email protected]  DRY MASS Mass of an organism after removal of its water content. HOW TO PREPARE A DRY MASS 1.Heat gently in an oven or an incubator at a low temperature 2. about 80-degree Celsius to increase rate of evaporation without burning the organic matter) 3.After a suitable period of time, leave it to cool and weight. 4. Repeat heating and reweight it until two successive weights become equal to make sure that it has lost all its water content CELL :00201110983031 00201110983031 [email protected]  IMPORTANT DEFINITIONS Classification: living organisms can be sorted into groups on the bases of shared features in morphology and anatomy. Morphology: means external features. Anatomy: means the study of the Internal structure of living organisms.  KINGDOM: the largest order and they are group of living organisms that share the similar features and each kingdom is divided into many phyla. EXAMPLE plant kingdom and animal Kingdom  PHYLUM: group of living organisms that share the similar features and each phylum is divided into classes. Example : phylum Arthropoda  CLASS : group of living organisms that share the similar features and each class is divided into orders. Example: Class Insects And Class Arachnids.  ORDER : group of living organisms that share the similar features and each order is divided into families.  FAMILY: group of living organisms that share the similar features and each family is divided into genus.  GENUS: group of living organisms that share the similar features is divided into smaller groups each is known as species  SPECIES: is a group of organisms which have a lot of features in common and can breed with each other producing young fertile offspring. Examples of species humans ,cat ,and dogs. CELL :00201110983031 00201110983031 [email protected]  importance of classification 1. To facilitate the study of living organisms. 2. To facilitate the identification of living organisms. 3. Classification systems aim to reflect evolutionary relationships The binomial system of naming species Means giving each organism a name of two words. The first represents genus it begins with a capital letter. The second represents species, it begins with a small Letter. The name is written LATIN in italics, or underlined. Example: the scientific name of humans is Homo sapiens Homo represents genus. sapiens represents species. Notice The above system is the traditional system it depends on morphology and anatomy. There are more accurate classification systems such as cladistics which is based on DNA structure. CELL :00201110983031 00201110983031 [email protected]  1. Explain That Classification Systems Aim To Reflect Evolutionary Relationships By classifying organisms, it is also possible to understand evolutionary relationships. By studying the anatomy of different groups of vertebrates it is possible to gain an insight into their evolution. 2.Explain that classification is traditionally based on studies of morphology and anatomy  Classification is traditionally based on studies of morphology (the study of the form, or outward appearance, of organisms)  anatomy (the study of their internal structure, as revealed by dissection). 3.List the features in the cells of all living organisms, limited to cytoplasm, cell membrane and DNA as genetic material All living organisms have certain features in common, including the presence of cytoplasm and cell membranes, and DNA as genetic material. 4. List the features in the cells of all living organisms, limited to ribosomes for protein synthesis and enzymes involved in respiration All living organisms also contain ribosomes in the cytoplasm, floating freely or attached to membranes called rough endoplasmic reticulum (ER). Ribosomes are responsible for protein synthesis. CELL :00201110983031 00201110983031 [email protected]  THE FIVE KINGDOMS 1.Kingdom prokaryotes (Monera or prokaryotes) 2. Kingdom protoctista (protoctista) 3. Kingdom fungi. 4 Kingdom plantae. 5. Kingdom animalia. 1. Kingdom prokaryotes (Monera or prokaryote) prokaryotes are Organisms with no nucleus while organisms known as eukaryotic organisms with nucleus ) Example bacteria shapes of bacteria 1-Spiral 2-Spherical 3-Rod shaped CELL :00201110983031 00201110983031 [email protected]  THE MAIN CHARACTERISTICS OF PROKARYOTIC ORGANISMS 1.Have no nucleus and no organelles except ribosomes 2. The ribosomes are smaller than the other kingdoms 3.Have circular DNA not associated with protein 4.Many types may contain circulating of DNA called plasmids 5.Many types are covered with a slime couple for protection 6. The bacterial cell is surrounded by a cell wall made of proteins and carbohydrates forming a substance called murein 7. its cytoplasm contains stored food in the form of glycogen and lipids. 8. May have flagella (singular flagellum) used in movement 9. May contain chlorophyll to carry out photosynthesis 2. Kingdom Protoctista Involve unicellular animals (known as protozoa and multicellular organisms’ seaweeds. 1. Cells contain nucleus 2. Some have cell wall and chloroplasts known as algae Examples Amoeba, paramecium CELL :00201110983031 00201110983031 [email protected]  3.Kingdom fungi 1. organisms with eukaryotic cells. 2.Have cell walls made of chitin and sometimes chitin and cellulose. 3.Most of them are multicellular but few are unicellular such as yeast. 4. Never motile (self-propelled or can move by itself) as they have no cilia or flagella. 5. Body usually made of hyphae 6. The whole body of a fungus is called mycelium. 7. Reproduce by spores (but yeast reproduce by budding). Comparison BACTERIA FUNGI Have a unicellular form Formed of thread -like structures Have a cell wall made of murein each is Have no nucleus (DNA without a known as hypha and collectively are nuclear envelope called mycelium There are types Hypha contains many nuclei in the of bacteria contain bacterial cytoplasm. chlorophyll and can carry out but yeast is a unicellular fungus) photosynthesis. The cell wall made of chitin. Reproduce by simple binary fission. CELL :00201110983031 00201110983031 [email protected]  Comparison Yeast Other types of fungi Unicellular 1. Reproduce by budding in Formed of hyphae favorable – 2. but reproduce by spore formation. 2. Reproduce by spore formation in 3. May be parasitic or saprophytic unfavourable conditions organism. is not a parasitic organism 4.Kingdom plants The main characteristics of flowering plants: 1-Contain chlorophyll and make their food by photosynthesis 2-Produce flowers for reproduction 3.Produce fruits enclosing seeds 4-Seeds germinate in suitable conditions producing new plants. 5-Organisms with eukaryotic cells. 6-Have cell walls containing mainly cellulose Examples Ferns and flowering plants CELL :00201110983031 00201110983031 [email protected]  Types of flowering plants MONOCOTYLEDON DICOTYLEDON 1 Have narrow leaves(strap-shaped) with parallel veins. 1. have broad leaves with network of 2 The seed contains one cotyledon. branched veins. 3 Have fibrous roots. 2. the seed contains two cotyledons. 4-The number of stomata is equally distributed in the upper and lower 3. have main tap root with lateral surfaces of the leaves. roots. 5. Floral parts such as petals are 4. stomata are usually found in the three or their multiples. lower surface. 5. floral parts are four or five or their multiples. CELL :00201110983031 00201110983031 [email protected] 1) Plants with roots, stems (called rhizome) and leaves (the leaves of fern are called fronds) 2) Do not produce flowers. 3) Reproduce by spores produced on the underside of the fronds. 4) The parts that produce spores are called sporangia (singular is called sporangium 5. kingdom animal 1. Organisms with eukaryotic cells. 2. Multicellular organisms differentiated into tissues. Often motile can move) 3. Have no cell wall. 4. Heterotrophic organisms (means cannot make their own food but obtain it by eat organisms). CELL :00201110983031 00201110983031 [email protected]  Phylum vertebrate Vertebrates are the living organisms which have a vertebral (a backbone). The main classes of vertebrates: 1-Fish 2- Amphibians 3-Reptiles 4- Birds 5- Mammals 1. CLASS FISH A. Bony Fish made of bones Characteristics And adaptation of fish 1. Have streamlined body shape to decrease resistance of water. 2 Covered with scales for protection. 2. Have lateral line for sensation. 3. Have gills for breathing. Cartilaginous fish skeleton is made of cartilages EX : SHARK CELL :00201110983031 00201110983031 [email protected]  2.CLASS REPTILES The main characteristics: 1. Reptiles are land-living vertebrates. 2. Dry scaly skin and the outer layer of epidermis forms a pattern of scales. This dry, scaly skin helps reduce water loss. 3. the eggs of most species have a tough, paperlike 4. shell. So, reptiles are not limited to damp habitats, and they do not need water in which to breed. 5. Reptiles are cold-blooded, but they can try to regulate their temperature. Ex. Reptiles include lizards, snakes, turtles, tortoises and crocodiles 3.CLASS AMPHIBIAN The main characteristics: 1-Have four limbs. 2-Have moist skin with fine capillaries for gaseous exchange (to help their small lungs). 3-Have external ear drum for hearing. 4-Their eyes are protruded to be able to see while the body is submerged in water. 5-Their nostrils (nasal. Openings) are found at the top of the head to be a able to breathe while swimming in water. CELL :00201110983031 00201110983031 [email protected]  NOTICE They lay soft eggs in a jelly- like coat that hatch into tadpoles. (The jelly used to absorb water and swell to act as shock absorber) 7-Their early stages tadpoles are adapted to life in water as follows: Have external gills for breathing Have tails for swimming in water Have streamlined shape to decrease resistance of water 4.CLASS BIRDS The main characteristics: 1. Are covered with feathers which a. Act as an insulating layer b. Decrease the density of the bird to help in flying. c. Is covered with a waterproof oil in order not to absorb water 2. Have beaks modified according to the type of the food. 3.Their fore limbs are modified into wings 4. Have tails to control their direction during flying 5. Their ear drums are found deep in their heads 6. Their females lay eggs with hard shells Examples: eagle, owl and hawk CELL :00201110983031 00201110983031 [email protected]  5.CLASS MAMMALS The main characteristics: 1. Have hairy skin or fur 2. Have external ear pinnae or flap 3. The females have mammary glands that secrete milk 4. Have four limbs 5. Have teeth with different types (other vertebrates have one type only) Example: humans, cats, dogs and bats Note: Explain Bats are not considered birds? because:  They have no feathers  They do not lay eggs  They have no beaks But considered as mammals because:  They have hairy skin  They have ear pinnae  They give birth CELL :00201110983031 00201110983031 [email protected]  VIRUS The main characteristics: Viruses have many characteristics of livings and also have many characteristics of non-livings, therefore: Viruses are considered as link or intermediate stage between livings and non- livings. It is difficult to classify viruses among living organisms. - Characteristics like living organisms: a. Have a core DNA or RNA b. Have proteins c. Can reproduce - Characteristics like non-living things: a. Have no cytoplasm or cell organelles b. Do not carry out any function of life except reproduction inside living cells VIRUS BACTERIA Smaller than a bacteria Larger than virus. - A virus has a protein coat (capsid) - Has a cell wall made of proteins, consists of units called Capsomers lipids and sugars. - Has no cell membrane - Has a cell membrane. - Contains no cytoplasm - Contains cytoplasm. - Contains no cell organelles - Contains few cell organelles such as - Cannot carry out any function of life ribosome. except reproduction. - Can carry out all the functions of the - Cannot be found except as a parasite living organisms. in living cells - Can live free or as a parasite CELL :00201110983031 00201110983031 [email protected]  PHYLUM ARTHROPODS Main Characteristics 1. Invertebrates, have segmented body. (Between segments there are flexible joints whichpermit movement) 2. Have exoskeleton made of chitin for protection and support 3. Have pairs of jointed legs to facilitate their movement 4. In most arthropods the segments are grouped together to form distinct regions, e.g. head,thorax and abdomen The Main Classes of Arthropods 1. Insects 2. Arachnids 3. Crustaceans 4. Myriapods A. CLASS INSECTS The Main Characteristics 1.) The body is divided into head, thorax and abdomen 2.) Have three pairs of jointed legs 3.) Have one pair of antennae 4.) Have compound eyes (few types have simple eyes) Adaptation of insects 1. Have compound eyes for wide vision (a compound eye is an eye composed of many units and lenses) 2. Have antenna for sensation 3. Are small to hide from enemies 4. Have jointed legs for rapid movement 5. Have segmented bodies to facilitate their movement 6. Have exoskeleton for protection and support CELL :00201110983031 00201110983031 [email protected]  B) CLASS ARACHNIDS The main Characteristics: 1)The body is divided into 2 parts only Cephalothorax (head and thorax fused together) and Abdomen 2.) Have four pairs of jointed legs originated from cephalothorax. Usually the legs end with claws for catching preys 3.) Have no wings 4.) Have simple eyes 7. 5.) Have no antenna but a pair of Chelicerae or Pedi-palps which are used to hold prey. Adaptation of Arachnids Have jointed legs for rapid movement Have segmented body to facilitate their movement Have exoskeleton for protection comparison INSECTS ARACHNIDS 1.Body is divided into three regions, 1. Body is divided into two regions only (head, thorax and abdomen) (Cephalothorax and Abdomen) 2. One Pair of antennae is attached to 2. Have no antenna but a pair of head chelicerae which are used to hold prey 3. Three pairs of jointed legs 3. Four pairs of jointed legs originated originated from thorax from cephalothorax 4. One pair of compound eyes (but few 4. Usually have several pairs of simple have simple eyes) eyes 5. May have wings 5. No wings CELL :00201110983031 00201110983031 [email protected]  B) CLASS CRUSTACEAN The Main Characteristics 1.) The body is divided into two parts only (Cephalothorax and Abdomen) 2.) Have two pairs of antennae 3.) Have one pair of stalked compound eyes 4.) Most of them are aquatic, respire by gills 5.) Usually have more than four parts of legs (or appendages) 6.) Have no wings Adaptation of Crustaceans 1. Have antenna for sensation 2. Have stalked compound eyes for wide field of vision 3. May have gills for breathing in water Examples: crabs, lobsters and shrimps B) CLASS MYRIAPODS The Main Characteristics 1.) Are Arthropods (have exoskeleton, segmented body and pairs of jointed legs) 2.) Have head, but the body cannot be obviously divided into thorax and abdomen 3.) Have a pair of legs at each body segment CELL :00201110983031 00201110983031 [email protected]