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Cells

A cell is a basic unit of life. It is the basic building blocks that makes all living things. Cells come from other cells, splitting into identical cells in a process called Mitosis. These daughter cells have identical replicates of chromosomes. Cells are responsible for carrying out essential life processes such as metabolism, growth, reproduction, and responding to stimuli from the environment.

Cells are the building blocks of all living things. They are so small that they can only be seen through a microscope. There are many different types of cells, including animal cells and plant cells. Animal cells have a cell membrane, cytoplasm, and a nucleus. Plant cells also have these structures, as well as a cell wall and chloroplasts.

Cells have different functions depending on their type. For example, red blood cells transport oxygen to different parts of the body, while nerve cells send messages throughout the body. Cells can also reproduce, either through mitosis or meiosis.

Another process called Meiosis is a special process of producing cells for reproduction like sperm cells and egg cells that have half the normal chromosomes.

Cells are the functional and structural units of living organisms that are needed for growth, reproduction and sustaining life. Cells can exist as single-cellular organisms (prokaryotic cells) to a myriad of multi-cellular organisms (eukaryotic cells)

Cells are small compartments that hold all the biological materials needed to carry out the function of life. It has specialised structures called organelles with distinct functions that help the cell to operate. Different combinations of organelles will create a cell with a different function to the organism. If a cell’s compartment breaks or an organelle is missing or fails, the cell will then die.

Plant cells and Animal cells.

There are two types of cells, plant cells and animals cells. Plant cells have a cell wall that protects the cell from injury. It also has organelles called chloroplast that conduct photosynthesis.

Main Parts of a plant cell:

1. Cell wall
2. Cell membrane
3. Chloroplast
4. Cytoplasm
5. Nucleus
6. Vacuole

Main Parts of an animal cell:

1. Cell membrane
2. Cytoplasm
3. Nucleus
4. Vacuole

Types of animal cells

There are many types of animal cells, each with its own specific structure and function. Here are some examples:

1. Red blood cells: Also known as erythrocytes, red blood cells are responsible for carrying oxygen from the lungs to the rest of the body. They are small, disc-shaped cells that lack a nucleus and are filled with hemoglobin, a protein that binds to oxygen.
2. Nerve cells: Also called neurons, these specialized cells are responsible for transmitting electrical impulses throughout the body. They have a unique structure, with long extensions called axons and dendrites that allow them to communicate with other nerve cells.
3. Muscle cells: There are three types of muscle cells in animals: skeletal, smooth, and cardiac. Skeletal muscle cells are responsible for movement, smooth muscle cells are found in the walls of organs and help with involuntary movements, and cardiac muscle cells are found in the heart and are responsible for pumping blood.
4. Epithelial cells: These cells line the surfaces of organs and structures throughout the body, such as the skin, the lining of the intestines, and the lining of blood vessels. They are responsible for protection, secretion, and absorption.
5. Fat cells: Also called adipocytes, these cells store energy in the form of fat. They are found throughout the body and can expand or shrink in size depending on the body’s energy needs.

Animal Cells

Animal cells are the basic unit of structure and function in animals. They have a complex structure, and several distinct components that work together to carry out the life processes of the cell. Animal cells are complex structures with many distinct components that work together to carry out the life processes of the cell. Each organelle has a specific function, and the overall structure of the cell is critical to its proper functioning. Here’s a summary of the structure of animal cells:

1. Cell membrane: The cell membrane is a thin, flexible barrier that surrounds the cell, regulating the movement of materials in and out of the cell.
2. Cytoplasm: The cytoplasm is the gel-like substance that fills the cell, providing support and a site for many of the cell’s metabolic reactions.
3. Nucleus: The nucleus is a membrane-bound organelle that contains the cell’s genetic material in the form of DNA.
4. Mitochondria: Mitochondria are membrane-bound organelles that are the site of cellular respiration, which is the process by which cells produce energy.
5. Endoplasmic reticulum: The endoplasmic reticulum is a network of membranous tubules and sacs that is involved in the synthesis, modification, and transport of proteins and lipids.
6. Golgi apparatus: The Golgi apparatus is a series of stacked membranes that is responsible for processing and packaging proteins and lipids for transport to other parts of the cell or outside of the cell.
7. Lysosomes: Lysosomes are membrane-bound organelles that contain digestive enzymes, which break down macromolecules and cellular debris.
8. Cytoskeleton: The cytoskeleton is a network of protein fibers that helps to maintain the shape and structure of the cell, as well as playing a role in cellular movement.

Plant Cells

Plant cells are eukaryotic cells that have a complex structure, with several distinct components that work together to carry out the life processes of the cell. Here’s a summary of the structure of plant cells:

1. Cell wall: Plant cells have a rigid cell wall that provides structural support and protection to the cell.
2. Cell membrane: The cell membrane is a thin, flexible barrier that surrounds the cell, regulating the movement of materials in and out of the cell.
3. Cytoplasm: The cytoplasm is the gel-like substance that fills the cell, providing support and a site for many of the cell’s metabolic reactions.
4. Nucleus: The nucleus is a membrane-bound organelle that contains the cell’s genetic material in the form of DNA.
5. Chloroplasts: Chloroplasts are membrane-bound organelles that are the site of photosynthesis, which is the process by which plants produce energy from sunlight.
6. Mitochondria: Mitochondria are membrane-bound organelles that are the site of cellular respiration, which is the process by which cells produce energy.
7. Endoplasmic reticulum: The endoplasmic reticulum is a network of membranous tubules and sacs that is involved in the synthesis, modification, and transport of proteins and lipids.
8. Golgi apparatus: The Golgi apparatus is a series of stacked membranes that is responsible for processing and packaging proteins and lipids for transport to other parts of the cell or outside of the cell.
9. Vacuole: Plant cells have a large central vacuole that is involved in storage, waste management, and maintaining turgor pressure.

Chloroplast: A special organelle

Found in plant cells and eukaryotic algae that conducts photosynthesis. It uses the pigment chlorophyll that absorbs sunlight energy with presence of water and carbon dioxide to produce energy storage molecules ATP and NADPH whilst freeing oxygen from water.

Chloroplasts are specialized organelles found in the cells of plants, algae, and some other photosynthetic organisms. They are the site of photosynthesis, the process by which light energy is converted into chemical energy in the form of organic molecules.

Chloroplasts contain a green pigment called chlorophyll, which absorbs light energy from the sun. This energy is then used to power the conversion of carbon dioxide and water into glucose and oxygen through a series of chemical reactions.

Chloroplasts have a unique structure, with a double membrane that surrounds the organelle and a series of flattened, disc-like structures called thylakoids inside. The thylakoids are arranged in stacks called grana, and the space surrounding the thylakoids is called the stroma.

The thylakoids contain the chlorophyll and other pigments needed for photosynthesis, and the stroma contains the enzymes and other molecules needed for the chemical reactions of photosynthesis to occur.

Leaf Structure

The structure of a leaf is highly specialized to support the process of photosynthesis. Here’s how:

1. Cuticle: The cuticle is a waxy, water-resistant layer on the outer surface of the leaf that helps to prevent water loss.
2. Epidermis: The epidermis is a thin, transparent layer of cells that covers the surface of the leaf. It contains stomata, which are small pores that allow gases to enter and exit the leaf.
3. Mesophyll: The mesophyll is the middle layer of the leaf and is where photosynthesis takes place. It contains two types of cells: palisade mesophyll cells and spongy mesophyll cells. Palisade mesophyll cells are located near the upper surface of the leaf and contain the majority of the chloroplasts, which are the organelles that carry out photosynthesis. Spongy mesophyll cells are located below the palisade mesophyll cells and are loosely packed, allowing for gas exchange.
4. Veins: The veins of the leaf contain the vascular tissue that transports water and nutrients throughout the plant. The xylem, which transports water, is located on the upper side of the vein, while the phloem, which transports nutrients, is located on the lower side of the vein.

The specialized structure of the leaf allows for efficient gas exchange, with the stomata allowing for the entry of carbon dioxide needed for photosynthesis and the exit of oxygen produced during photosynthesis. The chloroplasts located in the palisade mesophyll cells are positioned to maximize the absorption of light energy, while the vascular tissue ensures that the products of photosynthesis are transported to other parts of the plant where they are needed.

Cell Wall

Cell walls are only found in plant cells and surrounds a cell membrane, Made of cellulose, it protects the plant cell, filtering nutrients and maintains the shape of the plant to support plant parts. (the equivalent of the skeletal structure in animals) It also provides elasticity to plants, helping plants to bend in the wind or move its leaves in the direction of sunlight.

Cell walls can be tough, flexible and rigid. It helps prevent over pressure of plant cells, keeping the cell from over expansion. Up to three cell walls can be found in plant cells.

Cells walls have small holes called plasmodesmata in it that allows waste and nutrients to pass. It is also the reason during a drought, where water can be lost to the surrounding, the cell loses its turgidity and leaves the plant limp. However, the cell wall will still maintain its basic shape and will be filled back to its original shape when there is presence of water.

1. found only in plants
2. made of cellulose

They serve a number of important functions, including:

1. Providing support and protection: Cell walls help to maintain the shape and structure of the cell, protecting it from external stresses and providing mechanical support to the plant.
2. Regulating water balance: The cell wall allows water and other small molecules to pass through it, which helps to regulate the water balance within the cell.
3. Preventing cell lysis: The cell wall provides a protective layer around the cell, preventing it from bursting or undergoing lysis when exposed to changes in osmotic pressure.
4. Facilitating cell-to-cell communication: Cell walls can contain channels or pores that allow for the exchange of signals and nutrients between neighboring cells.
5. Serving as a barrier to pathogens: Cell walls can provide a physical barrier to pathogens, preventing them from entering the cell and causing infection.

Cell Membrane

Cell membrane separates the interior of a cell from its surrounding. Like our skin, it acts as a barrier to the environment and protects the cell. It also controls the movement substances into and out of the cell. (for example oxygen, carbon dioxide and steroids) It is composed of lipids and proteins.

The cell membrane, also known as the plasma membrane, is a thin, semi-permeable barrier that surrounds the cells of plants and other organisms. It serves a number of important functions in plant cells, including:

1. Regulating what enters and exits the cell: The cell membrane controls the movement of molecules in and out of the cell, allowing essential nutrients to enter and waste products to exit.
2. Maintaining cell shape and structure: The cell membrane provides structural support to the cell, helping to maintain its shape and prevent it from bursting under changes in osmotic pressure.
3. Facilitating cell-to-cell communication: The cell membrane contains receptors and other proteins that allow cells to communicate with each other, coordinating processes such as growth, development, and responses to the environment.
4. Serving as a barrier to pathogens: The cell membrane can help to prevent the entry of pathogens, such as viruses and bacteria, into the cell.
5. Transporting ions and other molecules across the membrane: The cell membrane contains channels and transporters that allow for the movement of ions and other molecules across the membrane.

The cell membrane is a vital structure in plant cells in helping to maintain the integrity of the cell while also allowing for the exchange of nutrients and information between cells.

Mitochondria

Mitochondria are the organelles of a cell that take in nutrients, break it down and produce energy for the cell in a process known as cellular respiration. As the powerhouses of the cell, chemical reactions within the cell produces the energy in a two membrane organelle, as compared to others with only one membrane.

The outer membranes protects and covers the inner membrane. The inner membrane is shaped perfectly in folds to increase surface area that increases the rate of chemical reactions. The fluid inside is called the matrix.

Mitochondria are membrane-bound organelles found in the cells of plants and other eukaryotic organisms. They play a crucial role in the production of energy for the cell, through a process called cellular respiration. Here are the functions of mitochondria in plant cells:

1. Energy production: Mitochondria are the site of aerobic cellular respiration, which is the process by which cells convert glucose and other organic molecules into ATP, the molecule that provides energy to the cell.
2. Storage of calcium ions: Mitochondria are also involved in the storage and release of calcium ions, which are important for muscle contractions, nerve impulses, and other cellular processes.
3. Programmed cell death: Mitochondria play a role in programmed cell death, or apoptosis, which is a natural process that helps to eliminate damaged or abnormal cells from the body.
4. Heat production: In certain plant tissues, mitochondria can also produce heat through a process called thermogenesis. This can help plants to survive in cold environments.
5. Regulation of cell signaling: Mitochondria are involved in the regulation of cell signaling, which involves the transmission of information between cells.

Mitochondria are essential organelles in plant cells, responsible for providing the energy needed for growth, development, and survival. They also have other important functions related to cellular processes and signaling.

Vacuole

A vacuole is a membrane bound organelle that is present in all plant cells and some animal cells. It is larger in plant cells than animal cells. Vacuoles contain water, nutrients and waste products. (Organic, inorganic molecules including enzymes)

Vacuoles have no basic shape or size, with its variance in accordance to the requirements of the cell. Like cell walls, vacuoles also provides support and maintains the cell structure for the plant cells.

They serve a number of important functions in plant cells, including:

1. Storage: Vacuoles can store a variety of substances, such as water, nutrients, pigments, and waste products. This allows plants to regulate their internal environment and respond to changes in their surroundings.
2. Support: Large central vacuoles found in plant cells can help to provide structural support to the plant, by maintaining turgor pressure and regulating the shape and size of the cell.
3. Digestion: Some vacuoles can contain enzymes that help to break down macromolecules and other cellular debris.
4. Defense: Vacuoles can also play a role in defense against pathogens and herbivores, by storing toxic compounds that deter or kill invaders.
5. Cellular signaling: Vacuoles can play a role in cellular signaling, by storing signaling molecules and other compounds that help to regulate cell growth and development.

Cytoplasm

Cytoplasm is all of the material inside a cell minus the cell nucleus. The main component is a gel like substance cytosol which is made of 80% watering usually colorless, with organelles making up the rest of cytoplasm.

Cytoplasm is the gel-like substance found inside the cell membrane of plant cells and other eukaryotic organisms. It fills the space between the cell membrane and the organelles of the cell and performs a number of important functions, including:

1. Support: Cytoplasm helps to maintain the shape and structure of the cell, providing a framework for the organelles and other structures within the cell.
2. Metabolism: Many metabolic reactions take place in the cytoplasm of plant cells, including glycolysis, the first step in cellular respiration.
3. Transport: Cytoplasm contains various protein fibers and other structures that help to transport materials within the cell, such as vesicles that carry molecules from the endoplasmic reticulum to the Golgi apparatus.
4. Cellular processes: Many important cellular processes occur in the cytoplasm of plant cells, such as protein synthesis, cell division, and signal transduction.
5. Storage: Cytoplasm can also serve as a storage site for certain molecules and compounds, such as glycogen in animal cells.

Nucleus

The nucleus of a cell is the control centre and acts as the manager of the cell. It  contains information and gives instructions to other organelles to function within the cell. It also stores hereditary genetic information, DNA, that allows cell division and reproduce. Only advanced eukaryote cells have a nucleus. It usually occupies 10% of the space within a cell. The nucleus is a critical organelle in plant cells, providing storage, organization, and control of genetic material, as well as playing a role in other important cellular processes such as gene expression and cellular signaling.

The nucleus is a membrane-bound organelle found in the cells of plants and other eukaryotic organisms. It contains the genetic material of the cell in the form of DNA, and plays a crucial role in controlling cellular functions. Here’s a summary of the function of the nucleus in plant cells:

1. DNA storage and organization: The nucleus stores the genetic material of the cell in the form of DNA, which is organized into chromosomes. The DNA contains the instructions for the synthesis of proteins and other molecules needed for cellular function.
2. Gene expression: The nucleus regulates gene expression, controlling which genes are turned on or off in response to various signals and environmental cues.
3. Replication and cell division: The nucleus is involved in DNA replication, which is necessary for cell division and the production of new cells.
4. RNA synthesis: The nucleus is also responsible for the synthesis of RNA, which is a crucial step in the production of proteins.
5. Cellular signaling: The nucleus is involved in cellular signaling, allowing cells to communicate with each other and coordinate their functions.

Special Cells for Plants

Root Hair Cell

Root Hair Cells are specialised cells with no chloroplast as there is no light in the ground. It has a structure for absorbing more water and minerals from the soil with long projections, hence an increase in surface area to help in the efficient absorption of water and nutrients.

Here’s a summary of the specialization of root hair cells in plants:

1. Increased surface area: Root hair cells have long, thin, finger-like projections that increase the surface area of the cell. This allows for more efficient absorption of water and nutrients.
2. Thin cell walls: Root hair cells have thin cell walls that are permeable to water and other small molecules, allowing for the easy diffusion of these substances into the cell.
3. Large central vacuole: The large central vacuole in root hair cells helps to maintain turgor pressure, which allows the cell to maintain its shape and remain in contact with the soil.
4. Root hair zone: The root hair zone is the region of the root where root hair cells are located. It is characterized by a high concentration of root hairs, which allows for more efficient absorption of water and nutrients.

Guard Cell

Guard cells are found on the epidermis of the leaves, stems and parts of a plant that requires gaseous exchange. Usually found as a pair, guard cells form a stomatal pore, with the ability to open and close to regulate gaseous exchange. The opening and closing of the stomata are controlled by water concentration moving into the cell.

When water moves into the guard cell, it swells up and the stomata opens to allow gaseous exchange since plants respire throughout the day. The gap needed for photosynthesis is bigger in the day to allow more carbon dioxide in and oxygen out, while at night, with no need for photosynthesis, the gap will be small but allow enough oxygen in for respiration.

However, a wide open stoma will also allow water vapour to escape from the plant and requires transpiration from the roots to replenish the plant. If water availability is critically low, for example, during a drought, water will start leaving the guard cells and close the stoma opening, stopping further water losses. This helps protect the plant from dehydration.

Guard cells are specialized cells found on the surface of plant leaves, and they play a crucial role in regulating gas exchange and water loss through small openings called stomata. Here’s a summary of the specialization of guard cells in plants:

1. Stomata regulation: Guard cells are responsible for regulating the opening and closing of stomata in response to changes in environmental conditions. This allows for the regulation of gas exchange and water loss, which is essential for the survival of the plant.
2. Cell shape and flexibility: Guard cells have a unique kidney-shaped structure that allows them to bend and change shape in response to changes in turgor pressure. This allows the stomata to open and close in response to changing environmental conditions.
3. Chloroplast presence: Some guard cells contain chloroplasts, which are responsible for carrying out photosynthesis. This provides the energy needed to power the transport of ions and other molecules that regulate stomatal opening and closing.
4. Signal perception: Guard cells are able to perceive and respond to a variety of environmental signals, such as light, temperature, and humidity. This allows them to adjust the stomatal opening and closing response to optimize gas exchange and water conservation.

In summary, the specialization of guard cells in plants allows for the efficient regulation of gas exchange and water loss, which is essential for the survival of the plant. The unique structure and function of guard cells helps the plant to adapt to a wide variety of environmental conditions and maintain homeostasis.

Animal Cells

Differences of plant cells and animal cells

Plant cells and animal cells are both eukaryotic cells, but they have some key differences in structure and function. Here are some of the main differences between plant cells and animal cells:

1. Cell wall: Plant cells have a rigid cell wall made of cellulose, which provides support and protection to the cell. Animal cells do not have a cell wall.
2. Chloroplasts: Plant cells have chloroplasts, which are organelles that are the site of photosynthesis, the process by which plants produce energy from sunlight. Animal cells do not have chloroplasts.
3. Vacuoles: Plant cells have a large central vacuole that is involved in storage, waste management, and maintaining turgor pressure. Animal cells may have small vacuoles, but they are not as large or as central as those found in plant cells.
4. Shape: Plant cells tend to be more regular in shape, with a rectangular or square shape, while animal cells are more irregular in shape.
5. Mitosis: Plant cells typically undergo cytokinesis through the formation of a cell plate, while animal cells undergo cytokinesis through the formation of a cleavage furrow.
6. Lysosomes: Animal cells contain lysosomes, which are organelles that contain digestive enzymes for breaking down waste materials. Plant cells have a similar function, but it is carried out by different organelles called vacuoles.
7. Due to a lack of cell wall, animal cells can come in a lot of different shapes and sizes leading to different functions.

Cell division

Cell division is the process by which cells reproduce, and it is essential for the growth, development, and repair of tissues in all living organisms. There are two main types of cell division: mitosis and meiosis.

Mitosis is the process by which a single cell divides into two identical daughter cells. It is used for growth and repair of tissues, and for asexual reproduction in some organisms. The process of mitosis includes several stages, including prophase, metaphase, anaphase, and telophase. During these stages, the cell’s DNA is replicated and separated into two identical sets, and the cell membrane and cytoplasm divide to produce two identical daughter cells.

Meiosis is a type of cell division that is used for sexual reproduction. It involves two rounds of cell division, resulting in the production of four genetically diverse daughter cells. Meiosis includes two stages: meiosis I and meiosis II. During meiosis I, homologous chromosomes pair up and exchange genetic material, resulting in the production of two haploid daughter cells. During meiosis II, these daughter cells divide again to produce four haploid daughter cells, each with a unique combination of genetic material.

Cell division for meiosis is a type of cell division that happens in the cells of the body that are used for sexual reproduction. During meiosis, one parent cell divides into four daughter cells that are different from each other and from the parent cell.

This process is important because it allows for the combination of genetic material from two parents, which creates offspring that are genetically diverse. Meiosis involves two rounds of cell division and a process called crossing-over, which helps to create genetic diversity by shuffling the genetic material between the homologous chromosomes.

Animal cells can arrange itself to perform specialised functions. It can replicate and the nucleus contains DNA information to organise itself to make organs like our bones, kidney or the heart.

Bone growth during puberty

Bone growth is controlled by several hormones, including growth hormone, insulin-like growth factor 1, and sex hormones such as estrogen and testosterone. During puberty, these hormones are produced in greater quantities, which leads to an increase in bone growth and development.

The process of bone growth during puberty occurs through a process called endochondral ossification. This involves the conversion of cartilage to bone in the growth plates, which are areas of developing bone tissue near the ends of long bones. As the cartilage in the growth plate is replaced by bone tissue, the bone becomes longer and thicker.

The growth plates are most active during puberty, which is why bone growth is greatest during this time. The growth plates fuse when the person reaches full skeletal maturity, which typically occurs in the late teenage years or early adulthood.

In addition to hormonal regulation, bone growth during puberty is also influenced by nutrition, physical activity, and other environmental factors. A healthy diet with adequate amounts of calcium and vitamin D, as well as regular physical activity, can help to support bone growth and development during puberty.

How do cells work?

Cells work through a variety of mechanisms, including communication, energy production, and cellular specialization.

One of the key functions of cells is to carry out metabolic reactions. These reactions involve the transformation of molecules into different forms, which can be used for energy or to build new structures in the cell. Cells use specialized organelles, such as mitochondria and chloroplasts, to carry out these reactions.

Cells also communicate with each other to coordinate their activities. This communication can take place through chemical signals, such as hormones or neurotransmitters, or through physical interactions, such as the formation of cell junctions. In multicellular organisms, cells work together to carry out complex functions, such as the formation of tissues and organs.

In addition, cells are specialized to carry out specific functions in the organism. For example, red blood cells are specialized to carry oxygen, while nerve cells are specialized for transmitting electrical signals. These specialized cells are created through a process of cellular differentiation, which involves the expression of specific genes that determine the cell’s function.

How is a human cell made?

Human Cell

Human Blood

Blood is a vital component of the human body, responsible for delivering oxygen, nutrients, and hormones to tissues, as well as removing waste products. Blood is produced in the bone marrow, which is the spongy tissue found in the center of many bones.

Blood is made up of several components, including red blood cells, white blood cells, and platelets. Red blood cells are responsible for carrying oxygen throughout the body, while white blood cells are part of the immune system, helping to fight off infections. Platelets are responsible for blood clotting, which helps to stop bleeding when a blood vessel is damaged.

Stem cells in the bone marrow are responsible for producing all of the different types of blood cells. These stem cells can differentiate into several different types of cells, including red blood cells, white blood cells, and platelets.

The production of red blood cells is regulated by a hormone called erythropoietin, which is produced by the kidneys in response to low oxygen levels in the body. Erythropoietin stimulates the bone marrow to produce more red blood cells, helping to increase the oxygen-carrying capacity of the blood.

The production of white blood cells is also regulated by several different hormones, including interleukins and colony-stimulating factors. These hormones stimulate the production of different types of white blood cells, which play a variety of roles in the immune system.

Blood contains four main components:

1. red blood cell
2. white blood cell
3. plasma
4. platelets

It carries out many functions including

• transporting oxygen and nutrients/energy throughout the body
• removing carbon dioxide from body tissues
• forming blood clots to stop bleeding
• carrying cells and antibodies to fight infection and heal
• transport and remove waste material to be filtered out by kidneys and liver.
• regulating body temperature

Blood cells are formed from stem cells in the bone marrow.

Red Blood Cells

Red in color when it is oxygen rich, accounts for 40-45 percent of blood volume, shaped biconcave to increase surface area to aid in gaseous exchange. It has no nucleus and allows the cell to be flexible and easily change shape to reach every corner of the body. However, that limits the lifespan of red blood cells to approximately 120 days. 2 million red bloods are produced every second.

It carries a protein hemoglobin that carries oxygen from the lungs to the body and exchange for carbon dioxide back to the lungs to be disposed.

The process of making red blood cells begins in the bone marrow, which is the spongy tissue found in the center of many bones.

The bone marrow contains stem cells, which are capable of developing into different types of blood cells, including red blood cells. The stem cells develop into immature red blood cells called erythroblasts, which then mature into fully functional red blood cells.

The production of red blood cells is regulated by a hormone called erythropoietin, which is produced by the kidneys. When the body needs more red blood cells, such as when there is a low oxygen level in the blood, the kidneys produce more erythropoietin, which signals the bone marrow to produce more red blood cells.

The process of making red blood cells takes about seven days from start to finish. During this time, the developing red blood cells go through several stages of development, gradually acquiring the characteristics that allow them to efficiently carry oxygen throughout the body.

Red blood cells are very important because they are responsible for carrying oxygen from the lungs to the rest of the body. They do this through a protein called hemoglobin, which is found in the red blood cells.

Hemoglobin is a protein that is able to bind to oxygen molecules. When the red blood cells pass through the lungs, the hemoglobin in the cells binds to oxygen molecules in the air, forming a compound called oxyhemoglobin. The red blood cells then carry this compound through the bloodstream to the rest of the body.

When the red blood cells reach tissues in the body that need oxygen, the hemoglobin releases the oxygen molecules so that they can be used by the cells. This happens because the concentration of oxygen in the tissues is lower than the concentration of oxygen in the red blood cells, so the oxygen molecules are able to diffuse out of the cells and into the tissues.

Once the oxygen has been released, the red blood cells pick up carbon dioxide, which is a waste product produced by the cells. The carbon dioxide is carried back to the lungs, where it is exhaled, and the process of oxygenation begins again.

White Blood Cells

White blood cells are the army of the body, protecting the body from infection by overcoming bacteria and viruses. Much smaller in concentration than red blood cells, with 1% of blood volume, white blood cells consists of neutrophils, T. lymphocyte and B. lymphocyte.

White blood cells are a very important component of the immune system, which is responsible for protecting the body against infection and disease. Unlike red blood cells, which are responsible for carrying oxygen throughout the body, white blood cells play a variety of roles in the immune response.

There are several different types of white blood cells, each with its own specialized function. For example, neutrophils are responsible for attacking and destroying invading bacteria, while lymphocytes are responsible for recognizing and destroying foreign invaders such as viruses.

The production of white blood cells is regulated by several different hormones, including interleukins and colony-stimulating factors. These hormones stimulate the production of different types of white blood cells, which play a variety of roles in the immune response.

White blood cells are able to move through the bloodstream and into tissues throughout the body, allowing them to quickly respond to any invading pathogens. Once they have identified a pathogen, white blood cells work together to attack and destroy it, helping to prevent the spread of infection and disease.

Other components in our blood

Platelets and plasma are two important components of blood that play different but equally vital roles in the body.

Platelets are small, disc-shaped cell fragments that are responsible for blood clotting. When a blood vessel is damaged, platelets rush to the site of the injury and stick to the damaged area, forming a plug that helps to stop the bleeding. Platelets also release chemicals that help to activate the clotting process, which involves the formation of a fibrin meshwork to seal the damaged blood vessel. Without platelets, even a small injury could lead to excessive bleeding, which could be life-threatening.

Plasma is a yellowish fluid that makes up about 55% of the total volume of blood. It is composed mainly of water, but also contains a variety of dissolved substances, including proteins, hormones, and waste products. Plasma helps to transport nutrients, hormones, and waste products throughout the body, as well as regulate body temperature and maintain blood volume.

The proteins found in plasma, including albumin, globulins, and fibrinogen, play a variety of roles in the body, such as maintaining osmotic pressure, transporting nutrients, and aiding in blood clotting. Some hormones, such as insulin and thyroid hormone, are also transported in the blood plasma.

Single Cell Organisms

Single-cell organisms are living organisms that consist of only one cell. They are the simplest and smallest living organisms, and they can be found in almost every environment on Earth, from the deepest parts of the ocean to the hottest deserts.

Single-cell organisms can be divided into two main groups: prokaryotes and eukaryotes. Prokaryotes are simple cells that lack a nucleus and other membrane-bound organelles, while eukaryotes are more complex cells that have a nucleus and other membrane-bound organelles.

Examples of prokaryotic single-cell organisms include bacteria and archaea, while examples of eukaryotic single-cell organisms include protozoa, algae, and yeast.

Despite their small size and relative simplicity, single-cell organisms are capable of carrying out a wide variety of functions, such as obtaining nutrients, reproducing, and responding to their environment. Some single-cell organisms, such as bacteria, play important roles in the functioning of ecosystems, such as by decomposing organic matter or fixing nitrogen.

How to use a microscope?

Here are the basic steps to use a microscope:

1. Adjust the lighting: Turn on the light source and adjust the brightness as needed to provide sufficient illumination for the sample.
2. Place the sample on the stage: Position the sample on the stage and secure it in place using clips or a slide holder.
3. Choose the lowest magnification: Begin with the lowest magnification objective lens, typically 4x or 10x.
4. Focus on the sample: Use the coarse focus knob to move the objective lens closer to the sample until it is in focus. Then, use the fine focus knob to make small adjustments to bring the sample into sharp focus.
5. Adjust the magnification: Once the sample is in focus, switch to a higher magnification objective lens (e.g. 40x or 100x) to examine the sample in greater detail. Repeat the focusing process as needed for each magnification.
6. Observe and record: Observe the sample and record any observations or measurements as needed.
7. Clean up: When you’re finished, turn off the microscope and clean the lenses with lens paper or a soft cloth to remove any oil or debris that may have accumulated.

It’s important to follow the specific instructions for the microscope you are using, as different types of microscopes may have different controls and settings. Always handle microscope components carefully to avoid damage, and be sure to use appropriate safety precautions when handling specimens, particularly if they are potentially hazardous.

Extra Information

Genetics

DNA, or deoxyribonucleic acid, is a molecule that contains the genetic instructions for the development, function, and reproduction of all living organisms. It is found in the cells of all living organisms, from bacteria to plants to animals.

The structure of DNA is a double helix, consisting of two strands of nucleotides that are held together by hydrogen bonds. Each nucleotide is composed of a sugar molecule, a phosphate group, and a nitrogenous base, which can be one of four types: adenine (A), guanine (G), cytosine (C), or thymine (T).

The sequence of these nitrogenous bases along the DNA strand forms a genetic code, which contains the instructions for the development and function of the organism. This genetic code is read by the cell in order to produce the proteins that are needed for various functions in the body.

DNA replication is the process by which DNA is copied before cell division, ensuring that each new cell has a complete set of genetic instructions. DNA can also undergo mutations, which are changes in the sequence of the nucleotides. Some mutations can be harmful, causing diseases or disorders, while others may be neutral or even beneficial.

 Largest Cell

The largest cell in the world is the ostrich egg cell, which is about 5.5 inches (14 cm) long and 4.5 inches (11 cm) wide. While the ostrich egg cell is technically a single cell, it is so large that it is visible to the naked eye.

However, it’s important to note that the ostrich egg cell is not the largest cell in terms of volume or mass. Some types of algae, for example, can grow to be much larger in terms of both size and complexity. The title of the largest cell can also depend on how the cell is defined, as some cells may be made up of multiple nuclei or other structures.

Is there single cell organisms that has chloroplasts?

Yes, there are single-cell organisms that have chloroplasts. The most well-known example is the algae, which are a diverse group of photosynthetic organisms that range from unicellular forms to multicellular forms such as seaweed. Many species of algae are single-celled and have chloroplasts, which they use to carry out photosynthesis and produce their own food.

Other examples of single-celled organisms that have chloroplasts include some species of protists, which are a diverse group of eukaryotic organisms that are not classified as animals, plants, or fungi. For example, some species of Euglena are single-celled protists that have chloroplasts and are capable of carrying out photosynthesis.

The ability to photosynthesize provides these single-celled organisms with a way to produce energy and synthesize organic compounds from simple molecules such as carbon dioxide and water. This ability has helped to make algae and other photosynthetic single-celled organisms an important part of aquatic ecosystems, providing food and energy for a wide variety of other organisms.

Neurons

Neurons transmit signals through a process called “neural conduction,” which involves the movement of electrical and chemical signals between neurons and other cells in the nervous system.

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