Lecture 10 Diversity of Nature Survey Kingdom Survey

Lecture 10: Diversity of Nature Survey Kingdom Survey Prokaryotes Kingdom Survey Protista Kingdom Survey Fungi Kingdom Survey Plantae Kingdom Survey Animalia Prepared by Mayssa Gh. ANNOUM

Overview Taxonomy organisms. is the ordered division and naming of 1. Binomial Nomenclature by (Carolus Linnaeus) Two key features of Carolus Linnaeus system remain useful today: two-part names for species( a binomial) by Latin Scientific names. and hierarchical classification. → The first part is the name of the genus. → The second part, called the species (nickname), is unique for each species within the genus. Example: Homo sapiens where Homo is the genus and sapiens is the specific epithet. Meaning ( wise man).

Binomial name is written in specific way: → First letter of first name should be a capital letter. → First letter of the second name should be a small letter. Two parts of a species name should be italicized or underlined separately: Rosa indica or Rosa indica Both parts together name the species (not the specific epithet alone).

2. Hierarchical Classification Linnaeus introduced a system for grouping species in increasingly broad categories. The taxonomic groups from broad to narrow are: domain, kingdom, phylum, class, order, family, genus, and species Each taxonomic unit at any level of hierarchy is called a taxon (plural, taxa). BACTERIA ANIMALIA EUKARYA ARCHAEA PLANTIA FUNGI PROTIST

Species: Panthera pardus Fig. 26. 3, page 537 Genus: Panthera Family: Felidae Order: Carnivora Class: Mammalia Phylum: Chordata Kingdom: Animalia Bacteria Domain: Eukarya Archaea

Kingdom Survey Prokaryotes are found almost everywhere, including places too acidic, salty, cold, or hot for most other organisms. Prokaryotic species are also very well adapted to more normal habitats- the lands and waters in which most other species are found. They have an amazing genetic diversity

Kingdom Survey Prokaryotes Their ability to adapt to a broad range of habitats helps to explain why prokaryotes are the most abundant organisms on Earth. Their collective biological mass is at least ten times that of all Eukaryotes. Prokaryotes are divided into two domains: bacteria and archaea

Kingdom Survey Prokaryotes Most prokaryotes are unicellular, although some species form colonies (refers to several individual organisms of the same species living closely together). Prokaryotic cells typically have diameters in the range of 0. 5 -5µm, much smaller than the 10 -100 µm diameter of many eukaryotic cells. Prokaryotic cells have a variety of shapes, the three most common of which are spheres (cocci), rods (bacilli), and spirals. Prokaryotes are well organized, achieving all of an organism’s life functions within a single cell.

The most common shapes of Bacteria 1 µm (a) Spherical (cocci) 2 µm (b) Rod-shaped (bacilli) 5 µm (c) Spiral Fig. 27. 2

Kingdom Survey Prokaryotes Cell-Surface Structure All prokaryotic cells have cell wall, which maintains cell shape, provides physical protection, and prevents the cell from bursting in a hypotonic environment. The cell walls of prokaryotes differ in molecular composition and construction from those of eukaryotes. Most bacterial cell walls contain peptidoglycan, a network of modified-sugar polymers cross linked by short polypeptides. Archaeal cell wall contain a variety of polysaccharides and proteins but lack peptidoglycan.

Kingdom Survey Prokaryotes Motility Of the various structures that enable prokaryotes to move, the most common are flagella ( sing, flagellum). Flagella may be scattered over the entire surface of the cell or concentrated at one or both ends. Prokaryotic flagella are one tenth the width of eukaryotic flagella and very different from them in their molecular composition and their mechanism of propulsion.

Kingdom Survey Prokaryotes Reproduction In a favorable environment, Prokaryotes have a potential to reproduce quickly by binary fission. A single prokaryotic cell divides into 2 cells, which then divides into 4, 8, 16, and so on. Under optimal conditions, many prokaryotes can divide every 1 -3 hours; some species like E. coli, can produce a new generation in only 20 min. In reality, prokaryotic reproduction is limited. The cells eventually exhaust their nutrients supply, poison themselves with metabolic wastes…

Kingdom Survey Prokaryotes have both harmful and beneficial impacts on humans. Some tend to be the bacteria that cause illness in humans, called pathogenic bacteria Example: Mycobacterium tuberculosis, which cause the lung disease tuberculosis. Other prokaryotes have positive interactions with humans, and some play essential roles in agriculture and industry.

Kingdom Survey Protista Protist is the informal name of the kingdom of mostly unicellular eukaryotes. Protists are very small eukaryotes and thus have organelles and are more complex than prokaryotes. Most protists are unicellular, but there are some colonial and multicellular species.

Kingdom Survey Protista Types of protists are the following: Photoautotrophs, which contain chloroplasts Heterotrophs, which absorb organic molecules or ingest larger food particles Mixotrophs, which combine photosynthesis and heterotrophic nutrition Protists can reproduce asexually or sexually

Amoeba Euglena

Kingdom Survey Fungi are Eukaryotes, Heterotrophs – they cannot make their own food as plants and algae can. But unlike animals, fungi do not ingest their food. A fungus absorbs nutrients from the environment outside of its body. Many fungi accomplish this task by secreting powerful hydrolytic enzymes into their surroundings. These enzymes break down complex molecules to smaller organic compounds that the fungi can absorb into their bodies and use.

Kingdom Survey Fungi Other Fungi use enzymes to penetrate the walls of plant cells, enabling the fungi to absorb nutrients from the plant cell. Collectively, the different enzymes found in various fungal species can digest compounds from a wide range of sources, living or dead. As a result, a fungi take on many roles in ecological communities, with different species living as decomposers, parasites or mutualists.

Kingdom Survey Fungi The morphology of multicellular fungi enhances their ability to grow into and absorb nutrients from their surroundings. The bodies of these fungi form a network of tiny filaments, called hyphae. Hyphae consist of tubular cell walls surrounding the plasma membrane and cytoplasm of the cells. Unlike plant cell walls which contain cellulose, fungal cell walls are strengthened by chitin ( a strong flexible nitrogen- containing polysaccharide).

Kingdom Survey Fungi Fungal hyphae form an interwoven mass called a mycelium that filtrates the material on which the fungus feeds. Fungi produce spores through sexual or asexual life cycles. Spores can be carried long distances by wind or water. If they land in a moist place where there is food, they germinate, producing new mycelia.

Kingdom Survey Fungi Humans benefit from fungi’s services to agriculture and forestry as well as their essential role in making products like bread, plus they have great medical value by producing Antibiotics, ex. Penicillium. They can serve as decomposers of organic materials. They can be edible(ex. Mushroom). But some fungi can be pathogens and cause diseases in plants and animals.

Kingdom Survey Plants are eukaryotes, multicellular, photosynthetic, autotrophs. Plants cell have cell walls and chloroplasts. Plants cell walls are made of cellulose. Plants supply the ecosystem with oxygen and are the ultimate source of most food eaten by land animals.

Kingdom Survey Plants Green algae, also called charophytes, are the only algae that share four distinctive traits with land plants, they are the closest relatives of plants. 1. Rosette-shaped cellulose synthesizing complexes. 2. Peroxisome enzyme 3. Structure of flagellated sperm. 4. Formation of phragmoplast ( group of microtubules).

Kingdom Survey Plants Land plants can be informally grouped based on the presence or absence of vascular tissue. Vascular tissue: cells joined into tubes that transport water and nutrients throughout the plant body. Most plants have a complex vascular tissue system and therefore called: Vascular plants. Plants that do not have an extensive transport system are described as: Nonvascular plants.

Vascular plants They are grouped into: → Seedless vascular plants, ex. Ferns → Seed plants a seed is an embryo packaged with a supply of nutrients inside a protective coat. Seed plants can be divided into two groups, gymnosperms and angiosperms, based on the presence or absence of enclosed chambers in which seeds mature. ü Gymnosperms: are grouped together as “naked seed”. ü Angiosperms: consisting of all flowering plants, where seeds develop inside chambers called ovaries which originate within flowers and mature into fruits.

Nonvascular plants that do not have vascular tissues are commonly called bryophytes , Their life cycle has two generations: Sporophyte & Gametophyte. Example: Mosses

Fig. 29. 3, Example of charophytes. 5 mm Chara species, a pond organism Coleochaete orbicularis, a disk-shaped charophyte that also lives in ponds (LM) 40 µm

PLANT PHYSIOLOGY Plants like most animals, have organs composed of different tissues, which in turn are composed of cells of different types. Plants have three organs: roots, stems and leaves, these organs form a root system and shoot system (stem & leaves).

Cell growth A plant can grow throughout its life; this is called indeterminate growth. Some plant organs, such as most leaves, flowers stop growing after reaching a certain size, this is called determinate growth. → Meristems: are plant tissues that remains embryonic as long as the plant lives, and allow for indeterminate growth. 1. Apical meristems: are located at the tips of roots and shoots. - Apical meristems elongate shoots and roots, process known as primary growth. 2. Lateral meristems: add thickness to woody plants, in a process called secondary growth.

Growth occurs just behind the root tip in 3 zones of cells: 1. Zone of cell division. 2. Zone of elongation. 3. Zone of differentiation.

Type of plant tissues Each plant organ: root, stem or leaf has dermal, vascular, and ground tissues. Each of these three categories form a tissue system, a functional unit connecting all of the plant’s organs. Each tissue system is continuous throughout the plant.

Type of plant tissues The dermal tissue system: is the plant’s outer protective covering. Like humans skin, it forms the first line of defense against physical damage and pathogens. The vascular tissue system: carries out long-distance transport of materials between the root and shoot systems. There are two type of vascular tissues: Xylem: conducts water and dissolved nutrients upward from roots into the shoots. Phloem: transports sugars, from where they are made (leaves) to where they are needed ( roots and sites of growth).

Type of plant tissues The ground tissue system: ground tissue that is internal to the vascular tissue is known as pith, and ground tissue that is external to the vascular tissue is called cortex. The ground tissue system is not just filler. It includes various cells specialized for functions such as storage, photosynthesis, and support.

Common Types of Plant Cells Like any multicellular organism, a plant is characterized by cellular differentiation, the specialization of cells in structure and function. Cellular differentiation may involve changes both in the cytoplasm and its organelles and in the cell wall.

Common Types of Plant Cells The major types of plant cells are: 1. Parenchyma cells 2. Collenchyma cells 3. Sclerenchyma cells 4. The water-conducting cells of the Xylem 5. The sugar-conducting cells of the Phloem

Reproduction • Flowers and fruits are unique features of the angiosperms life cycle. • The life cycle of plants is characterized by an alternation of generations in which: → The Diploid (2 n): sporophytes produce spores by meiosis, these grow into (n) haploid gametophytes, ( male and female ). Seed development, form and function § After fertilization, each ovule develops into a seed. § The ovary develops into a fruit enclosing the seed(s).

Plant Hormones: helps coordinate growth, development, and responses to stimuli, and they are produced in very low concentrations: hormone Site of synthesis Function Auxin(IAA) Shoot apical meristems and young leaves Stimulates stem elongation regulates development of fruit Cytokinins roots Regulate cell division in shoots and roots Gibberellins Meristems of apical and roots Stimulate stem elongation , pollen development Brassinosteroids all plant tissues promote xylem differentiation , promote seed germination. Abscisic acid(ABA) all plant cells promotes stomatal closure during drought stress. Inhibits growth Ethelene all parts of plant Promotes ripening of fruits promotes flowering

Kingdom Survey Animalia Animals are multicellular , heterotrophic eukaryotes. Most animals reproduce sexually, with the diploid stage usually dominating the life cycle. Animal cells have a specific cell membrane performing selective permeability.

Kingdom Survey Animalia Animals can vary according to: I. The organization of tissues: True tissues are collections of specialized cells surrounded by membranous layers. (sponges lack true tissues). II. The body cavity: fluid or air space separating digestive tract from the outer body wall.

Kingdom Survey Animalia III. Symmetry Animals can be characterized by body plans (symmetry): § animals may lack symmetry (sponge) § or may have radial symmetry (sea anemone) § or bilateral symmetry (lobster). (a) Radial symmetry (b) Bilateral symmetry

Kingdom Survey Animalia Kingdom Animalia is grouped according to the presence or absence of backbone into: 1 - Vertebrates: animals with backbone, there are five classes: Mammals , Birds, Fish , Amphibians , Reptiles 2 - Invertebrates: animals without backbone. they account for 95% of known animal species, ex. Worms, Arthropods, Echinoderms, sponges, Mollusks…….