Separation and Ultrastructure of Proplastids from Dark-grown Euglena Cells

Green algae and plants, including green stems and unripe fruit, harbor specialized organelles called chloroplasts to carry out photosynthesis. They coordinate both stages of photosynthesis — the light-dependent reactions and the light-independent reactions. The light-dependent reactions use sunlight to release oxygen and produce chemical energy in the form of ATP and NADPH, and the light-independent reactions capture CO2 and use ATP and NADPH to produce sugar.
Structure of Chloroplasts
A...

Cell division is essential for organismal growth and development. In animal cells, the central spindle and its associated proteins form the midbody, a structure that has an essential role in cytokinesis. In plants, the central spindle, along with the microtubules, actin, and other cell components, matures into the phragmoplast, which is necessary for cytokinesis. Unlike the stationary midbody, the phragmoplast expands centrifugally, eventually leading to the formation of the new cell wall.
The...

The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...

Cell division is essential for organismal growth and development. In animal cells, the central spindle and its associated proteins form the midbody, a structure that has an essential role in cytokinesis. In plants, the central spindle, along with the microtubules, actin, and other cell components, matures into the phragmoplast, which is necessary for cytokinesis. Unlike the stationary midbody, the phragmoplast expands centrifugally, eventually leading to the formation of the new cell wall.
The...

Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...

Protists are diverse eukaryotic microorganisms that lack the specialized tissues of plants and animals and the chitinous cell walls of fungi. Their early divergence within Eukarya resulted in structural, functional, and ecological diversity. They are classified into supergroups such as Archaeplastida, Excavata, Amoebozoa, Rhizaria, Alveolata, and Stramenopiles, determined through genetic analysis and structural similarities.Structural and Functional AdaptationsProtists have various adaptations...