Cell Wall Definition Around the inner plasma membrane, an outermost layer provides protection and strength to the cell. This outermost layer is the cell wall. Protoplast, a living structure, forms the non-living cell wall. The cell wall is not a characteristic of all types of cells. Some cells show their presence like plant cells, fungi, … Read more
Definition of Eukaryotic Cells Eukaryotic cells feature a membrane-bound, well-defined nucleus as well as several membrane-bound organelles, making them complicated in structure as well as function. The term “eukaryote” comes from the Greek words “eu” as well as “karyon,” which mean “true” as well as “nucleus,” respectively. When compared to prokaryotes, eukaryotic cells have a … Read more
Flagella and Cilia Definition Cilia and Flagella are cytoplasmic filamentous structures which protrude through the cell wall. They are the cell’s minute, highly distinct appendages. An entire cell is propelled by its flagella (singular form: flagellum), which are long, hair-like projections that protrude from the plasma membrane. Small hairlike structures called cilia (singular = cilium) … Read more
Nucleosome Model of Chromosome Chrosomes are self-replicating nucleic acid molecules that have particular organisational and functional characteristics and are essential for inheritance, mutation, variety and evolutionary advancement. Every chromosome’s structure is supported by many layers of DNA wrapped around proteins. Histones and non-histone chromosomal proteins are the traditional classifications for proteins which attach to DNA … Read more
Definition of Microtubules (What are Microtubules?) Microtubules are located within the cytoplasm of every eukaryotic cells, with the exception of human erythrocytes. Microtubules are small, empty, bead-like tubular structures that aid in cell shape maintenance. These are small hollow tubes present within cells that also serve as the cell’s motor. Figure: Diagram of Microtubules Image … Read more
Membrane Carbohydrate Individual cells as well as cellular compartments remain separated by cell membranes, which are selected boundaries. Membranes are made up of binding forces that hold carbohydrates, proteins, and lipids together. Carbohydrates are covalently bonded to proteins or lipids (glycolipids) and are a major constituent of cell membranes, where they serve as cell adhesion … Read more
Definition of Microfilaments Microfilaments, often referred as actin filaments, are components of a cell’s cytoskeleton. It is made up of two parallel polymers of G-actin that are coiled around each other in a helical configuration and have a diameter of 6 to 8 nanometers each. These filaments, which are found in all eukaryotic cells, have … Read more
Definition of Mitosis Mitosis is a type of cell division that occurs in the body. Mitosis is a cell division process in which one cell divides into two genetically identical daughter cells, resulting in cell reproduction and duplication. The number of chromosomes is preserved in both the daughter cells. Mitosis is a short period of … Read more
Definition Prophase For both mitosis and meiosis, prophase is the phase that follows interphase and is usually the first and longest phase in the cell cycle. The chromosomes are visible during this phase of DNA unwinding and chromatin condensation. What Happens in Prophase? During prophase, the DNA that was generated during the interphase phase is … Read more
Definition of Centrioles Near the nucleus, eukaryotic cells include two cylindrical, rod-shaped microtubular structures called centrioles. They are found in most algal cells (with the exception of red algae), moss cells, some fern cells, and most mammal cells, and lack a limiting membrane and DNA or RNA. Prokaryotes, red algae, yeast, cone-bearing and flowering plants … Read more