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 organs in a multicellular organism’s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One way that cells communicate is through direct contact with other cells. The points of contact that connect adjacent cells are called intercellular junctions.

In a multicellular organism, cells must communicate to work together in a coordinated manner. One way that cells communicate is through direct contact with other cells. The points of contact that connect adjacent cells are called intercellular junctions.
Intercellular junctions are a feature of fungal, plant, and animal cells. However, different types of junctions are found in different kinds of cells. Intercellular junctions found in animal cells include tight junctions, gap junctions, and...

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...

Positioning the cell division plane is a critical step during development and cell differentiation, particularly during mitosis when the plane is essential for determining the size of the two daughter cells. The cell division plane is perpendicular to the plane of chromosome segregation, but different types of organisms have different cell division mechanisms to suit their morphology and function. 
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division...

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...