Ethylene and Polyamines: Plant Growth Regulators
UNIT 20 – Ethylene and Polyamines
Definitions
Methionine: An amino acid formed from S-adenosylmethionine (SAM), a precursor in metabolic pathways, including ethylene and polyamine biosynthesis.
Ethylene: A developmental regulatory molecule (hydrocarbon, C2H4) in plants and animals. It has a simple chemical structure and is active in gaseous form. Its effects occur at very low concentrations and are evident in virtually all life cycle stages.
Triple Response: Ethylene’s effect in seedlings, causing reduced
Read MoreCell Biology and Nutrition Essentials
ITEM 1 Cell Parties
Mitochondria
Oval organelles that provide energy.
Reticulum
Sacks and interconnected channels where proteins and lipids are produced.
Vacuoles
Contain water and dissolved substances.
Lysosomes
Transform substances into simpler ones.
Cytoskeleton
Complex filaments forming a network.
Centrioles
Two hollow cylinders with walls formed by filaments.
Ribosomes
Small particles, free or attached, that manufacture proteins.
Golgi Apparatus
Stacks of membranous sacs that package substances manufactured
Read MoreBiological Classification & Tissue Types
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:
Human Skin Structure and Functions
Human Integumentary System
The integumentary system, or skin, weighs over 3-4 kg and covers about 1.5-2 m2. It’s the body’s largest organ, composed of distinct layers.
Skin Histology
The skin has three main layers:
- Epidermis: Squamous epithelial tissue made of flat cells forming a continuous layer. It’s stratified with multiple layers that keratinize.
- Dermis: Connective tissue providing mechanical support and protection.
- Hypodermis: Subcutaneous adipose tissue (not always considered a skin layer).
Epidermis
Read MoreFundamentals of Human Biology
1. Levels of Organization
Atoms: Chemical elements that make up living organisms.
Molecules: Components from which cells build structures, reaching cells from the blood.
Cells: The basic unit of living things, responsible for nourishment, waste elimination, interaction, and reproduction.
Tissue: A group of specialized cells combined for a particular function.
Organ: Composed of different tissues with a specific function.
Apparatus: Association of organs working together for a specific function.
Homeostasis:
Read MoreCell Division and Genetics: Meiosis, Mitosis, and Alterations
Meiosis, Mitosis, and Early Genetics
4 – Meiosis, mitosis, and early genetics and gene expression mechanisms, genetic alterations: enzymopathies and metabolic diseases, chromosomal anomalies: Down syndrome, Turner, Klinefelter, the “cat’s meow,” Edwards, and Patau.
Of the various forms of reproduction (division to multiply) in living cells, in humans, mitosis and meiosis both occur in interphase, prophase, metaphase, anaphase, and telophase (practice with plasticine models). Chromosomes are in the
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