There are about 200 different types of cells in the human body, but all cells on earth fit into only two categories; Prokaryotes and eukaryotes.
The two types of cells on earth
All cells on earth can be classified as both prokaryotic Cells or eukaryotic Cells. Eukaryotic organisms can be multicellular or unicellular, but prokaryotes are always unicellular organisms.
Eukaryotic cells are larger and more complex than prokaryotes and usually contain organelles that are absent in prokaryotic cells. This is because eukaryotes contain it membrane-bound organelles (how Nucleus, endoplasmic reticulum, Golgi apparatus, and Mitochondria), But not prokaryotes.
Types of eukaryotic cells
The four types of eukaryotic cells are animal cells, plant cells, fungal cells, and protists.
Animal cells are the basic building blocks of all animals, including birds, fish, reptiles, mammals, and amphibians. Like eukaryotic cells, they contain membrane-bound organelles (such as a nucleus, mitochondria, a Golgi apparatus, and an endoplasmic reticulum) and are surrounded by a plasma membrane.
Plants are made up of plant cells. Plant cells contain many of the same organelles that are common to all eukaryotes, but they contain additional structures that are not found in animal cells. For example, plant cells are surrounded by a tough cellulose-based structure called a cell wall. They also contain organelles called chloroplasts, which are the site of photosynthesis and enable plant cells to produce carbohydrates from carbon dioxide, water and light energy.
The Mushrooms The kingdom is made up of yeasts, powdery mildew, molds, and mushrooms. Fungal cells contain many of the structures and organelles found in plant and animal cells, such as the nucleus, mitochondria, cell membrane, mitochondria, Golgi apparatus, and endoplasmic reticulum. However, they do not contain chloroplasts. Although they have a cell wall, it is mostly made up of a polysaccharide called Chitin, rather than cellulose (as is the case with plant cells).
Protists are a very diverse group of organisms, and the Protista kingdom is made up of all eukaryotes that are not animals, plants, or fungi. Protist cells contain all of the membrane-bound organelles found in animal cells, and some types also contain chloroplasts. They can also have a cell wall made of cellulose.
Types of prokaryotic cells
Prokaryotic cells are smaller and simpler in structure than eukaryotic cells because they do not contain membrane-bound organelles. Prokaryotic organisms are always unicellular and can be bacteria or Archaea. Bacterial and archaeal cells have the same basic structure, but some of their components are made of different materials.
Bacteria are unicellular, prokaryotic organisms. Their cells do not contain any membrane-bound organelles, so they have no nucleus, mitochondria, endoplasmic reticulum, or Golgi apparatus. However, they have a cell membrane, cytoplasm, ribosomes, and free-floating loops of DNA. Bacterial cells also have a cell wall made from a polymer called Peptidoglycan (AKA Murein). Some bacteria have additional specialized structures, like that capsule (a sticky layer of carbohydrates that surrounds the cell) or Flagella (whip-like structures that allow the bacteria to move).
Archaea are also unicellular prokaryotes and contain many of the same structures found in bacterial cells. However, they typically have a different composition. For example, the bacterial cell wall contains peptidoglycan, but the archaeal cell wall does not. The plasma membrane in bacterial cells (and eukaryotes) is a lipid bilayer, but the plasma membrane of archaeal cells is a lipid monolayer. After all, the cell membrane in bacteria contains fatty acids, but the cell membranes of archaea contain a hydrocarbon called a hydrocarbon Phytanyl.
Types of cells in the human body
Adult humans are made up of around 37 trillion individual cells and around 200 different cell types. Some key cell types in the human body include stem cells, muscle cells, blood cells, bone cells, nerve cells, fat cells, sperm cells, and egg cells.
Muscle cells are the basic units of muscle tissue. These cells are highly specialized to facilitate muscle contraction and contain protein filaments (called) Myofibrils) and many mitochondria.
Stem cells are cells that can develop into other types of cells. They differentiate to make up all of the specialized cells in the human body and are found in both Embryos and certain adult body tissues (like that Bone marrow).
Bones are living tissues with their own network of blood vessels and are made up of different types of cells. The main types of bone cells are Osteoclasts (Cells that dissolve bone tissue)Osteoblasts (Cells that make new bone tissue), and Osteocytes (which are located in the bone and communicate with other bone cells).
Blood contains a number of cells. The three main types of blood cells are Red blood cells (which carry oxygen), White blood cells (which are components of the immune system, and Platelets (Cell fragments that allow blood to clot).
Nerve cells (AKA Neurons) make up the nervous system. Their key function is to carry messages between the body and the brain.
Fat cells are also known as Fat cells. They are specially adapted to store energy in the form of adipose tissue and are found throughout the body. The fatty tissue that is stored under the skin is called subcutaneous fat, and the fat that surrounds the internal organs is known as visceral fat.
Sperm are male reproductive cells. They are the smallest cell type in the human body and have various adaptations for fertilization, such as: tail (for swimming) and many Mitochondria (for power generation).
Female reproductive cells are called egg cells. Egg cells are much larger than sperm and contain a large amount of nutrient-rich cytoplasm to help the new organism develop.