SWOT with Narayankar

General characteristics of prokaryotic cells: i. Prokaryotic cells are primitive type of cells. ii. It does not have membrane bound cell organelles (like endoplasmic reticulum, Golgi complex, mitochondria, etc.) and well-defined nucleus (nuclear membrane is absent).  iii. Genetic material is in the form of nucleoid. iv. Cell envelope       a. Prokaryotic cell has chemically complex protective cell envelope having glycocalyx, cell wall & plasma membrane.       b. In some bacteria, glycocalyx occurs in the form of a slime layer (loose sheath). Other bacteria have a thick and tough covering called capsule. It helps in protection of bacterial cell.  v.  Cell Wall The Gram-positive bacteria show presence of peptidoglycan layer in the cell wall and Gram-negative bacteria show presence of murein in the cell wall. It gives mechanical strength to the cell. Note: In Gram-negative bacteria, cell wall is made up of two layers; inner layer of Murein peptidoglycan and outer layer of Lipopolysacc

i.Totipotency (totus entire, potential power) is the capacity or the potential of living nucleated differentiate into any other type of cell and thus, can form a complete new organism.  ii. A cell is totipotent as it has the entire genetic information of the organism stored in its nucleus. iii.Embryonic animal cells are totipotent and are termed as stem cells. Stem cells are used in curing many diseases. Therefore, they have great potential for medical applications.

i. The rigid, protective and supportive covering, outside the cell membrane is called cell wall. It is present in plant cells, fungi and some protists. ii.Algae show presence of cellulose, galactans, mannans and minerals like calcium carbonate in cell wall. iii.In other plants, it is made up of hemicelluloses, pectin, lipids and protein.  iv. Microfibrils of plant cell wall show presence of cellulose which is responsible for rigidity. v. Some of the depositions of cell wall are silica (grass stem), cutin (epiderma walls of land plants), suberin(endodermal cells of root), wax, lignin. vi. Function: Provides support, rigidity and shape to the cell. Protects the protoplasm against mechanical injury and infections.

i. Eukaryotic cells are the cells possessing well-defined nucleus and membrane bound organelles (like mitochondria, endoplasmic reticulum, ribosomes, Golgi complex etc.).  ii. Eukaryotes include protists, plants, animals and fungi.

In biology, the term "cell envelope" typically refers to the outermost layer or structure that surrounds a cell, particularly in prokaryotic cells like bacteria and archaea. The cell envelope consists of several components, including: 1. **Cell Membrane (Plasma Membrane)**: This is the innermost layer of the cell envelope and is composed of a lipid bilayer. It controls the passage of molecules in and out of the cell and plays a crucial role in maintaining cell integrity. 2. **Cell Wall**: Many prokaryotic cells have a cell wall located just outside the cell membrane. The composition of the cell wall varies among different species. In bacteria, for example, some have peptidoglycan cell walls, while others have different types of cell wall structures. 3. **Capsule or Glycocalyx**: Some bacteria have an additional outer layer called a capsule or glycocalyx. This layer is made up of polysaccharides and helps protect the cell and adhere to surfaces. 4. **S-Layer**: In some archaea

Certainly! Let's break down the statement about Gram-positive and Gram-negative bacteria cell walls: 1. **Gram-Positive Bacteria**:    - In Gram-positive bacteria, the cell wall is primarily composed of a substance called **peptidoglycan**.    - Peptidoglycan is like a protective mesh or layer that surrounds the bacterial cell. It provides structural support and helps the cell maintain its shape.    - Imagine it as a sturdy brick wall around the cell, with each "brick" made up of sugars and amino acids. 2. **Gram-Negative Bacteria**:    - In Gram-negative bacteria, the cell wall is also composed of peptidoglycan, but it's thinner than in Gram-positives.    - What makes Gram-negatives different is that they have an additional outer membrane that surrounds the peptidoglycan layer. This outer membrane is made up of a substance called **murein** or **lipopolysaccharides**.    - Think of it as an extra protective layer outside the peptidoglycan wall, like a second wall aro

Cilia and flagella are like tiny whip-like structures found in cells, and they both help with movement. However, they have some key differences: 1. **Number and Location:**    - **Cilia** are usually shorter and more numerous. They often cover the entire surface of a cell.    - **Flagella** are longer and usually there are fewer of them, typically just one or a few per cell. 2. **Motion:**    - **Cilia** move in a coordinated back-and-forth motion, like oars rowing a boat. This movement is used to move substances across the cell's surface or to propel the entire cell.    - **Flagella** move in a whip-like, undulating motion, similar to the way a fish swims. They are primarily used for cell propulsion, like a tail. 3. **Function:**    - **Cilia** are often found in places where things need to be moved, such as the respiratory tract, where they help move mucus and trapped particles out of the lungs.    - **Flagella** are typically used for cell movement. For example, they're foun