Basics of Botany PDF

Basics of Botany For 1st Year Chemistry, Fac. of Education– English Prof. Dr. Abla AM Farghl Professor Phycology / Dept. Botany, Fac. Science  Basics of Botany ‫أساسيات علم النبات‬ Higher plant Microo...

Basics of Botany For 1st Year Chemistry, Fac. of Education– English Prof. Dr. Abla AM Farghl Professor Phycology / Dept. Botany, Fac. Science  Basics of Botany ‫أساسيات علم النبات‬ Higher plant Microorganisms Terminology Botany: the science of plants Taxonomy: classification of plants Botany: the scientific study of plants and their relationships. Plants affect virtually everything we do in the world. Humans have relied on plants for survival and pleasure for centuries. Plants are the basis for many national and world economies How do we classify the living world? Early scientists classified organisms as either Animal or Plant. Animal Plant moved, had nervous systems Photosynthetic (autotrophic) and showed heterotrophic with a cell wall enclosing the nutrition cytoplasm  Classification of Living Organisms Biologists sort living organisms into groups to make it easier to study them. Grouping of living organisms is called biological classification. Living organisms are divided into five main groups called KINGDOMS. These are the bacteria, protists, fungi, plants and animals.  Plant kingdom Thallophyta Embryophyta Bacteria, Algae, Fungi Byrophyta, Pteridophyta, Spermatophyta Spermatophyta Gymnosperm Angiosperm  In this simple system of plants and animals, "plants" which had no recognizable stem/root/leaf regions were said to have a body termed a thallus and were termed Thallophytes. In this earliest classification system bacteria, fungi and algae were all put into this grouping.  Biodiversity on Earth Each Kingdom is very large and it contains many different types of organisms. 4000 Bacteria 66000 Fungi 150000 Protists 290000 Plants 1200000 Animals  ‫ كارولوس لينيوس‬Carolus Linnaeus Swedish botanist Famous for his work in Taxonomy: the science of identifying, naming and classifying organisms (plants, animals, bacteria, fungi, etc.). He was born in 23 May 1707 - in Råshult, Sweden, and died January 10, 1778,.  Seven Level Classification System Linnaeus used seven groups or taxonomic levels The broadest level Kingdom Phylum Class Order Family Genus Species The most specific level Each Kingdom can be divided into smaller groups Order Order Order Order  What is a cell? Definition of cell - In biology, the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body. A cell has three main parts: the cell membrane, the nucleus, and the cytoplasm. The cell membrane surrounds the cell and controls the substances that go into and out of the cell  Types of Cells Cells are similar to factories with different labourers and departments that work towards a common objective. Various types of cells perform different functions. Based on cellular structure, there are two types of cells: Prokaryotes Eukaryotes Eukaryotes Prokaryotes  W HAT THE WORDS MEAN Prokaryotes Eukaryotes  Pro = before  Eu = true  Karyose = kernel, which  Karyose = kernel, the represents the nucleus nucleus  So prokaryotes occurred  So eukaryotes are the before cells with a cells with a true nucleus nucleus  Ex. Found in animals,  Ex. Bacteria plants, and fungi (yeast)  Cyanophyta  Algae Difference Between Prokaryotic and Eukaryotic Cells Prokaryotic Cells  Prokaryotic cells have no nucleus. Instead, some prokaryotes such as bacteria have a region within the cell where the genetic material is freely suspended. This region is called the nucleoid.  They all are single-celled microorganisms. Examples include archaea, bacteria, and Cyanobacteria.  The cell size ranges from 0.1 to 0.5 µm in diameter. The hereditary material can either be DNA or RNA.  Prokaryotes generally reproduce by binary fission, a form of asexual reproduction.  They are also known to use conjugation – which is often seen as the prokaryotic equivalent to sexual reproduction (however, it is NOT sexual reproduction). Eukaryotic Cells  Eukaryotic cells are characterised by a true nucleus.  The size of the cells ranges between 10–100 µm in diameter.  This broad category involves plants, fungi, protozoans, and animals.  The plasma membrane is responsible for monitoring the transport of nutrients and electrolytes in and out of the cells.  It is also responsible for cell to cell communication.  They reproduce sexually as well as asexually.  There are some contrasting features ‫ السمات المتناقضة‬between plant and animal cells. For eg., the plant cell contains chloroplast, central vacuoles, and other plastids, whereas the animal cells do not.  Eukaryotic and Prokaryotic Cell Structure Typical Animal Cell Structure Prokaryotic Cell Eukaryotic Cell Cell Membrane Yes Yes Cell Wall Yes Yes Cilia or Flagella Yes, simple Yes, complex Endoplasmic Reticulum No Yes Golgi Complex No Yes Lysosomes No Yes Mitochondria No Yes Nucleus No Yes Ribosomes Yes, simple Yes, complex Today we recognize: 1. Monera (Prokaryotes): bacteria, blue green algae 2. Protista (protozoa, slime molds, algae). 3. Fungi 4. Plants 5. Animals Botanical nomenclature Genus species Vicia faba Fig. The prokaryotic cell is much simpler in structure, lacking a nucleus and the other membrane-enclosed organelles of the eukaryotic cell.  BACTERIA  The Bacteria are a group of single- cell microorganisms with prokaryotic cellular configuration.‫خلوي بدائي‬.  The genetic material (DNA) of prokaryotic cells exists unbound in the cytoplasm of the cells. ‫غير مرتبطة في‬ ‫سيتوبالزم الخاليا‬  There is no nuclear membrane, which is the definitive characteristic of eucaryotic cells.  The discipline of biology related to their study is called bacteriology.  Bacteria grow in a wide variety of habitats and conditions. Bacteria are so widespread.  They may be found on the air, soil, water, your body and also on the tops of mountains, the bottom of the deepest oceans, in the guts of animals, and even in the frozen rocks. Forms of bacterial cells Spiral  Most bacteria may be placed into one of three groups based on their response to gaseous oxygen..‫يمكن تصنيف معظم البكتيريا إلى ثالث مجموعات بناء على استجابتها لألكسجين‬ 1. Aerobic bacteria thrive ‫ تزدهر‬in the presence of oxygen and require it for their continued growth and existence. 2. Anaerobic, cannot tolerate gaseous oxygen, such as those bacteria which live in deep underwater sediments, or those which cause bacterial food poisoning..‫لتسمم الغذائي البكتيري‬ 3. Facultative anaerobes, which prefer ‫تفضل‬growing in the presence of oxygen, but can continue to grow without it.  Bacteria classified by the source of their energy, into two categories 1. Heterotrophs: derive energy from breaking down complex organic compounds that they must take in from the environment. 2. Autotrophs: fix carbon dioxide to make their own food source; this may be fueled by light energy (photoautotrophic), or by oxidation of nitrogen, sulfur, or other elements (chemoautotrophic).  Autotrophic Bacteria These bacteria are nonpathogenic, free living, self sustaining in nature, which prepare their own food by utilisation of solar energy and inorganic components like carbon dioxide, nitrogen etc They use carbon dioxide for obtaining carbon and utilise hydrogen sulphide (H2S) as the source of hydrogen to reduce carbon.  Autotrophic Bacteria. They are of two types: i) Photoautotrophs: These bacteria contain bacterio-chlorophyll can prepare their own food by fixing carbon dioxide the nature by the utilisation of solar energy. ii) Chemoautotrophs: -these are the bacteria which prepare they are food by deriving the energy from oxidation of inorganic substances like nitrogen dioxide, carbon dioxide etc. and they can also fix carbon dioxide and water for their nutrition.  Heterotrophic Bacteria These are bacteria which are unable to manufacture their own organic food and hence are dependent on external source. 1. Saprophytic Bacteria ‫البكتيريا المترممة‬ 2. Parasitic Bacteria ‫البكتيريا الطفيلية‬ 3. Symbiotic Bacteria ‫البكتيريا التكافلية‬  Saprophytic Bacteria These bacteria obtain their nutritional requirements from dead organic matter. They breakdown the complex organic matter into simple soluble form by secreting exogenous enzymes. They absorb the simple nutrients and assimilate them, during which they release energy. These bacteria have a significant role in the ecosystem, functioning as decomposers.  Saprophytic Bacteria The aerobic breakdown of organic matter is called as decay or decomposition. It is usually complete and not accompanied by the release of foul gases. - Anaerobic breakdown of organic matter is called fermentation. It is usually incomplete and is always accompanied by the release of foul gases. Anaerobic breakdown of proteins is called putrifaction.  Parasitic Bacteria  These are bacteria which occur in the body of animals and plants, obtaining their organic food from there.  Most of these bacteria are pathogenic, causing serious diseases in the host organisms either by exploiting them or by releasing poisonous secretions called toxins.  Symbiotic Bacteria  These are bacteria which live in a mutually beneficial association with other organisms.  Such bacteria derive the essential nutrients from their host organisms and in that process help the host through some of their biological activities. Familiar Example of Symbiotic Bacteria 1. The nitrogen fixing bacteria found in the root nodules of leguminous plants ‫النباتات البقولية‬. 2. The bacteria found in the human alimentary canal Root hair legumes Escherichia coli are nonpathogenic. 3. cellulose digesting bacteria which occur in the alimentary canal of ruminant mammals such as cows and goats. Mutualistic interaction inside cow rumen  Symbiotic Bacteria The bacteria found in the human alimentary canal Escherichia coli are nonpathogenic. These bacteria check the growth of harmful putrefying bacteria. In addition, these bacteria release vitamins K and B12 which are necessary for blood components. The human host provides shelter and food for these bacteria.