Biological Classification & Tissue Types

Posted on Nov 18, 2024 in Biology

Classification of Animals

Util-harmful-redundant.

Classification of Plants

Production of fruits, vegetable producers, or wood fiber producers.

Carl Von Linné described plant and animal species in SYSTEMA NATURAE.

Ernst Haeckel proposed the Protista kingdom:
Higher Protista (eukaryotic): algae, fungi, protozoa
Lower Protista (prokaryotes): bacteria

Robert Whittaker:
Prokaryotic or Monera: bacteria, archaea
Protista: fungi, mucous protozoa, some algae
Unicellular fungi: yeast; Multicellular fungi: fleshy mushroom
Plantae: mosses, ferns, flowering plants
Animalia: sponges, worms, insects, and vertebrates

Biogenesis Theory

Living cells come from pre-existing cells. A cell can only originate from another living cell.

Abiogenesis Theory

Life forms could appear spontaneously from inert matter (e.g., meat producing worms, which is actually due to microorganisms like bacteria and fungi).

I) Characteristics of Living Things

Highly organized, living organisms have a defined, complex structure divided into distinct levels:

a) Atomic level: CHONPS (Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur)
Properties:
1. Covalently share 1, 2, 3, and 4 electrons.
2. Light elements that can form covalent bonds.
3. Carbon atoms can form carbon skeletons and single bond chains.
4. Carbon-based systems in living organisms are often hydrogenated.

b) Molecular level: amino acids, monosaccharides
c) Macromolecular level: proteins, polysaccharides, lipids
d) Molecular aggregate level: core proteins, lipoproteins
e) Organelle level: mitochondria, lysosomes, smooth and rough endoplasmic reticulum (SER and RER)
f) Cellular level: plant cell, animal cell
g) Tissue level: nerve tissue, muscle tissue, epithelial tissue
h) Organ level: lung, heart
i) Organ system level: nervous system, respiratory system
j) Multicellular organism level: humans, plants, animals
k) Population level: group of organisms of the same species
l) Community level: interacting populations
m) Ecosystem level: communities and their environment

II) Metabolic Activity

Energy required for anabolic processes (synthesis) and catabolic processes (degradation) of biomolecules.

III) Reproduction Capability

Self-perpetuating over time through offspring.

IV) Irritability and Adaptation

Irritability: Responsiveness to physical and chemical changes.
Adaptation: Ability to exploit the environment for survival, causing temporary or permanent changes.








Tissues

Groups of cells with the same function.

Epithelial Tissue

Consists of continuous cell layers lining internal cavities; functions include protection, absorption, secretion, and sensation. Everything that enters or leaves the body passes through this tissue.

  • Squamous: Flat, slab-like cells, generally with a central nucleus; located on the skin surface, mucosa, esophagus, and vagina.
  • Cuboidal: Cube-shaped cells with lateral nuclei; line various channels like renal tubules.
  • Columnar: Elongated cells with nuclei at the base; line the stomach and intestines.
  • Ciliated: Cells with cytoplasmic projections that move foreign material; found in the ciliated respiratory system.
  • Sensory: Specialized cells for receiving stimuli; found in nostrils.
  • Glandular: Cuboidal and columnar cells capable of secreting substances like milk, sweat, serum, and saliva.
  • Exocrine Glands: Secrete products into ducts that lead outside the body or into cavities (e.g., digestive glands, sweat glands).
  • Endocrine Glands: Secrete products into the bloodstream or extracellular fluid for distribution.

Connective Tissue

Contains a fundamental substance (extracellular material) that is more or less liquid and amorphous; supports and connects all cells.

Tissues are classified by the characteristics of their matrix.

Fibrous Connective Tissue: Matrix is a thick, complex network of fibers secreted by the tissue’s cells.
Varieties: Tendons (flexible), ligaments (elastic), attached to bones, skin (collagen-rich).

Cartilaginous Tissue: Skeletal support during embryonic development; stiff but elastic.

Bone Tissue: Composed of yellow and red marrow cells; matrix is secreted in plates; light, comprising 18% of body weight.

Blood and Lymph:
Lymph: Colorless, composed of plasma, white blood cells, and formed elements.
Blood: Originates in bone marrow, lives about 120 days, 5 million/mm3, functions in transport of O2 and CO2, pH control.

Lymphocytes:
T cells: Responsible for cellular immunity.
B cells: Produce antibodies.
Monocytes: Phagocytize bacteria.
Neutrophils: Resist bacterial infection.
Basophils: Involved in inflammatory responses.
Platelets: Involved in blood clotting.

Muscle Tissue

Cells contain contractile elements; three types: smooth, cardiac, and striated.

Smooth: Involuntary, surrounds internal organs.
Cardiac: Heart wall.
Striated: 2-3 cm long, have peripheral nuclei; 40% of body weight.

Nervous Tissue

Neurons (Nerve Cells): Transmit impulses.
Glial Cells: Support neurons, provide nutrients, protect, and insulate (form myelin sheath); nervous tissue constituents are bundles of nerve fibers.
Ganglia: Clusters of nerve cells outside the central nervous system (CNS).
Tracts: Groupings of nerve fibers.

Plant Tissues

Basic, vascular, dermal.

Leaves: Photosynthetic parenchymal cells; spongy mesophyll cells with large, irregularly shaped spaces between them.

Substances enter and exit through vascular tissues and stomata.

Leaf vascular tissue is for transport (e.g., xylem transports water); stomata are small openings or pores surrounded by two specialized cells; plants lose water through stomata.

Stem: Green when young and photosynthetic; two important cell types:

Fiber cells: Provide structural support.
Phloem: Conducting tissue.

Structural Molecules

Inorganic

  • Do not contain carbon.
  • Water: Most abundant substance, solvent, high heat capacity, thermal conductor, polar.
  • Mineral Salts: Chloride, phosphate, sulfate, carbonate (involved in pH regulation).
  • Metal Ions: F, Cl, Br, Si, etc. (many are enzyme cofactors).

Organic


SI hold carbon. Tenras other atoms can cmo o, n, s, p
a) carbohydrate or carb to Cn (H2O)
· Monosaccharides, can be triose-tretrosa-pentose-hexose
glycosidic bond
à disaccharide (o + monosacardios)
à oligosaccharide (10 monosaccharides approx)
à polysaccharides (many monosaccharides)
b) lipid
Fatty Acids formed by 12 to 28 carbons
There are three fatty acids.
-Saturated simple
-Insaturadosà 1 double bond
Polinsaturadoà + 1-link.
· Neutral fat or triglyceride alcohol + 3 fatty acids.
· Phospholipids to fatty acid alcohol +2 + fosfoto
· Esterolesà cholesterol.
c)) protein complex and sometimes Chons P
There are 20 amino acids dif.

RNA synthesis (in cytoplasm)
Three types of RNA.
M RNA to occur in the nucleus = triplet codons.
T RNA to transport amino acids, has an anticodon.
Rà RNA allows the coupling of the two.

c) Vitamins A vital and lively.
– Comp. Natural food
-absent in diet
– Diseases for lack of vita avitaminosas