Category: Biology Questions

Plant cells have chloroplasts, plasmodesmata, a large central vacuole, cell wall, and plastids, whereas animal cells do not. Talking about animal cells, they have lysosomes and centrosomes.

Let us get familiar with the detailed discussion on three cell structures that plant cells have, but animal cells do not.

1. The Cell Wall

The cell wall endows with extra support and strength for the plant cell, so it does not get burst while gaining water by the endosmosis process.

In a plant cell, a structure to the plasma membrane is known as the cell wall. A cell wall is rigid covering protection for the cell and provides them with structural support. It also gives the shape to the cell.

Some protest cells and fungal cells also have cell walls. For instance, in the case of cellulose, while the main component of a prokaryotic cell wall is peptidoglycan, the primary organic molecule in the plant’s cell wall is cellulose. A polysaccharide is made up of a solid and long chain of glucose units. Whenever the nutritional information refers to dietary fiber it is, in turn, referring to the cellulose food content.

2. Chloroplasts

Chloroplast is the place where the process of photosynthesis occurs. Chloroplasts have their own ribosomes and DNA. Chloroplasts can be found in photoautotrophic eukaryotic cells like algae and plants. It functions in the photosynthesis process.

In the photosynthesis process, water, light energy, and carbon dioxide are used to make oxygen and glucose. This is the significant difference between animals and plants that plants make their own food while animals rely on other organisms.

3. Large permanent Vacuole

The large permanent vacuole stores several pigments, enzymes, ions, and inorganic and organic substances and plays an excellent role in osmoregulation.

Vacuoles are the essential component of the plant cells, and each plant cell has a large and central vacuole that occupies most of the cell. This central vacuole plays a crucial role in regulating the cell’s water concentration in altering environmental conditions.

In a plant cell, the liquid present inside the large central vacuole endows with the turgor pressure that is an outward pressure caused by the fluid present inside a cell.

Well, let us get a proper understanding of it by the common fact. Well, have you ever noticed that if you do not water a plant continuously for a few days, it wilts?

Undoubtedly, it does. That is all because the water concentration in the soil becomes lower as compared to the water concentration present in the plant. Water moves out of the cytoplasm and central vacuoles into the soil, and since this large central vacuole shrinks, it leaves the plant’s cell wall unsupported.

This loss of support results in the wilted appearance of the plant. And when this central vacuole is filled with water, it endows with a low energy means of the plant cell to expand. Additionally, this fluid can deter herbivory as the waste’s bitter taste discourages its consumption by the animals and insects. The large central vacuole also functions for protein storage in developing the seed cells.

Osmosis refers to a process by which a solvent’s molecules pass from a low concentration solution to a high concentration solution through a semi permeable membrane.

What is Osmosis?

Osmosis is a passive process that occurs devoid of any energy expenditure. Osmosis involves the movement of the molecules from high to low concentration regions until the concentrations become equal on either side of the membrane. Any of the solvents can undergo the osmosis process, including supercritical liquids and gases.

Osmotic Solutions

Osmotic solutions are of three different types. This includes:

• Isotonic Solution

An isotonic solution has the same solute’s concentration both outside and inside the cell.

• Hypotonic Solution

A hypotonic solution has a higher concentration of solute inside the cell as compared to outside.

• Hypertonic Solution

A hypertonic solution has a higher concentration of solute outside the cell as compared to inside. 

Osmosis Types

Osmosis is of two types. This includes:

• Exosmosis

Whenever a substance is placed in a hypertonic solution, the molecules of solvent move outside the cell, and the cell undergoes plasmolysis or becomes flaccid. This process is known as exosmosis.

• Endosmosis

Whenever a substance is placed in a hypotonic solution, the molecules of the solvent move inside the cell, and the cell undergoes deplasmolysis or becomes turgid. This process is known as endosmosis.

Effects of Osmosis on cells

The osmosis process affects every cell differently. For instance, if we talk about an animal cell, it will lyse when placed in a hypotonic solution compared to a plant cell. A hypotonic solution is considered an ideal solution for a plant cell because it has thick walls and it requires more water, so the cells will not burst even when placed in a hypotonic solution.

While talking about the animal cell, it survives only in an isotonic solution, while the plant cells in the same solution are no longer turgid, and the plant’s leaves droop.

However, the osmotic flow can be reversed or stopped, which is known as reverse Osmosis. This can be done by exerting external pressure on the solute’s sides. And the minimum pressure needed to stop the solvent transfer is known as osmotic pressure.

Example of Osmosis

Osmosis has a significant role to play in animals, plants, and humans. Here are a few examples of Osmosis.

• If a saltwater or freshwater fish is placed in water with varying salt concentrations, the fish dies because of the exit and entry of water in fish cells.
• The water absorption from the soil is because of the osmosis process. As the plant roots have a higher concentration as compared to the soil, so consequently the water flows into the roots.
• Individuals suffering from cholera are also affected by the osmosis process. The bacteria which overpopulate the intestine, reverse the absorption flow and does not allow the intestine to absorb the water, which further results in dehydration.
• The plant’s guard cells are also affected by the osmosis process. This happens when the plant cells are filled with water it results in the swelling up of the guard cells and opens up the stomata.
• Whenever the fingers are placed in water for a longer time, they become pruney because of the water flow inside the cells.

Differentiation takes place in multicellular organisms. It is a way for a primary cell to assign the jobs to sub- cells. The cell gets divided to perform specific roles which lead to the development and maturation of an organism. 

Differentiation is a specialization of cells for performing relatable tasks and functions in a body. This process of changing and modifying cells is called ‘Differentiation.’ 

Let us take an example of Stem cell divides into two cells. The one cell has been assigned the role of a white blood cell known as ‘Neutrophil’ and the other cell is divided as red blood cell known as ‘Erythrocyte.’ 

We know that the cell is the smallest unit of an organism. There are single-celled organisms and multi-cellular organisms. Both functions differently.  

Single-cell units perform all functions needed for the functionality of a proper life and they are good at doing all different things. While in the case of multi-cell organisms, each has its responsibility.  

• During differentiation, cells undergo many stages which lead to several changes in the structure and the function of a living being. 
• Specialized cells can be differentiated and differentiated cells cannot be further divided. Only undifferentiated cells can be divided or specialized.  

The zygote is a fertilized cell produced from the ovum and ovule. It is the first stage of fertilization and the form of the collision of male and female gametes. A Zygote carries all the characteristics of sperm and ovum which further become an individual. 

• This stage occurs in the first week of fertilization. 
• In the second stage, the separation of chromatids takes place on the fusion of meiosis with the sperm. 
• If the fertilization doesn’t occur in the Fallopian tube, the zygote moves down to the uterus.  
• After zygote formation, the embryo is developed which undergoes various changes to reproduce a baby. 

How do the Zygote forms? 

The zygote is formed when the male sperm enters the female’s fertilization, egg cell during the ovulation period. It is a stage when a developing cell gets divided into several cells and a zygote came out of the selected cell which further proceeds for the embryonic development. It prevents other sperm from entering the Fallopian tube and thus continues the further reproductive cycle. 

How are twins born? 

Generally, one egg splits up into one zygote. When an egg gets divided into two zygotes through mitosis, two embryos are formed sharing the same genetic material twins are developed. 

Children have been reading about the fact that plants make their food with the help of sunlight and water. Also, leaves are the primary part that prepares the essential nutrients by the process of ‘Photosynthesis.’ Have you ever thought of how do leaves manage to transfer the food to the When leaves transport food to the other parts of the plants? 

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Translocation is the process by which leaves transport prepared nutrients and all food (essential for the growth of the entire plant) to the other parts of the plant. The process takes place with the help of phloem and xylem. 

• Phloem has sieve tubes that are accountable for the distribution of food molecules to every part of the plant. 
• The transportation process of plants is Bi-directional. So, the food can go upward to downward and vice-versa depending on the location where the food is prepared and needed. 
• The part where food is present acts as ‘Source’ and the other parts are known as ‘Sink.’ 
• The source is usually ‘Green’ in colour and the Sink being the fruit part can be of any other colour.

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Turgid is a term used for a plant when its intakes excess water. In biology, the study of cells or tissues of a plant that gets swollen by absorbing water is known as ‘Turgidity.’ In this, the cell membranes of a plant push against the wall of cells and result in increased size. 

Turgid occurs in a plant cell because of Osmosis in which the liquid flows towards the higher concentration. Similarly, when this moment takes place in plants it is known as ‘Turgidity.’ 

• When a plant cell undergoes a lack of water and loses all the water, it is known as ‘Plasmolyzed.’ It is the opposite of ‘Turgidity.’ 
• The pressure created by the uptake of water on cells walls is known as ‘Turgid Pressure.’ 

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