Algae

• Green algae is a type of algae that contains chlorophyll and is commonly found in freshwater environments.
• The cell is the basic structural and functional unit of all living organisms
• Cells can be classified into two types: prokaryotic and eukaryotic
• Prokaryotic cells:

  • Do not have a nucleus
  • Have a simple structure
  • Examples include bacteria
• Eukaryotic cells:

  • Have a nucleus
  • Have complex structures
  • Examples include plant and animal cells
• Cell organelles are specialized structures within a cell that perform specific functions
• Cell organelles include:

  • Nucleus: controls cell activities and contains genetic material
  • Mitochondria: produces energy through cellular respiration
  • Chloroplasts: found in plant cells, responsible for photosynthesis
  • Endoplasmic reticulum: involved in protein and lipid synthesis
  • Golgi apparatus: packages and transports proteins
  • Lysosomes: contain enzymes for digestion
  • Vacuoles: store water and nutrients
  • Ribosomes: involved in protein synthesis
• Cell division is the process by which a cell divides into two daughter cells
• There are two types of cell division:

  • Mitosis: produces two identical daughter cells for growth and repair
  • Meiosis: produces gametes (sex cells) with half the number of chromosomes for sexual reproduction
• Cellular respiration is the process by which cells break down glucose to produce energy in the form of ATP
• Photosynthesis is the process by which plants convert light energy into chemical energy stored in glucose
• DNA (deoxyribonucleic acid) is the genetic material that carries the instructions for the development, functioning, growth, and reproduction of all organisms
• Genes are segments of DNA that code for specific traits or proteins
• Mutation is a change in the DNA sequence that can lead to variations in traits
• Natural selection is the process by which organisms better adapted to their environment tend to survive and reproduce more successfully
• Evolution is the change in the heritable characteristics of biological populations over successive generations
• Starch granules store excess energy from photosynthesis.
• Chlorophyll is found within the thylakoid membranes, which are stacked into grana.
• On the basis of habitat algae are classified into 3 group:

  Aquatic

  Terrestrial

  Algae of unusual habitat
• Some species of algae have evolved specialized structures called holdfasts that anchor them firmly to substrates.
• In aquatic habitats, algae may be free-floating or attached to surfaces such as rocks or plants.
• The cell wall of algae may be composed of various materials such as cellulose, chitin or silica.
• In some cases, algal cells form colonies through aggregation or fusion with other cells.
• Algae can also produce gas vesicles, which allow them to float at specific depths in water bodies.
• The evolutionary history of algae can be traced back more than 2 billion years ago when they were among the first organisms on Earth capable of carrying out oxygenic photosynthesis.
• Algae play important roles in ecosystems by producing oxygen through photosynthesis and serving as food sources for other organisms.
• Algae can also form symbiotic relationships with other organisms, forming lichens.
• They also contribute significantly to global carbon cycling and nutrient cycles.
• Algae can also grow on the surface of other organisms, forming symbiotic relationships known as lichens.
• Algae play important roles in ecosystems by producing oxygen during photosynthesis and serving as food sources for many marine animals.
• They contribute significantly to global carbon fixation and oxygen production.
• Algae play important roles in ecosystem functioning by providing food sources for herbivores and serving as primary producers in many marine environments.
• The mycobiont provides protection and nutrients while the photobiont performs photosynthesis.
• 1. Aquatic algae are found in fresh water and in saline water of the sea
• • Fresh water occur in fresh water that is ponds lakes rivers pools
  • Some fresh water algae are cladophora,odegonium,ulthorix,chara are found in slow running water
  • Whereas others such as chlamydomonas,hydrodictyon,volvox,spirogyra are found in stagnant water
• Marine forms of algae are found in saline water of the sea

  They are represented by the members of phaeophyceae(ectocarpus,fycus,sargassum)and rhodophyceae(polysiphonia)
• Aquatic algae may be either free floating eg;chlamydomonas,volvox, spirogyra

  Or they may be attached to the substratum with the help of holdfast with is a attachment disc like structure examples are cladophora,oedogonium ulthorix, chara.
• Algae can also grow on rocks or other surfaces underwater, forming colonies called thalli. These thalli can take various shapes depending on the species, including filamentous (like hair), sheet-like (like paper), or branching structures.
• Algae have different reproductive strategies based on their life cycle stages. Some reproduce sexually through the fusion of gametes, while others reproduce asexually through fragmentation or budding.
• Algae can form symbiotic relationships with animals, where one partner benefits from living together with another organism without harming it. For example, some corals host zooxanthellae, which are photosynthetic algae that live inside the coral's tissues and provide them with energy.