Question

Which of the following is correct about pseudopodia? (a) Formed by streaming of protoplasm (b) Formed in amoeba and neutrophile (c) Both (a) and (b) (d) None of these

Short answer

The correct answer is option (c): Both (a) and (b). Pseudopodia are formed by the streaming of protoplasm and they are formed in amoeba and neutrophiles.

Step-by-step solution

Understanding Pseudopodia

Pseudopodia, or 'false feet', are temporary projections of eukaryotic cells. Cells can extend these projections to move or to engulf something.

Applying the definition to option (a)

Pseudopodia are indeed formed by the streaming of protoplasm, or cytoplasmic contents. They are not permanent structures; the cell forms them by flowing its internal components in the direction it wants to move, or around the particle it wants to engulf.

Applying the definition to option (b)

Both amoebas and neutrophils, a type of white blood cell, use pseudopodia. Amoebas use them for moving and eating. Humans' neutrophils use them to move towards and engulf pathogens, once the neutrophil is in the tissue space.

Analyzing the information against the options

With the information from steps 2 and 3, it can be concluded that pseudopodia are formed by the streaming of protoplasm and they are formed in amoeba and neutrophile. Thus, the option (c) matches with our findings.

Key concepts

Eukaryotic cells

Eukaryotic cells are a fundamental aspect of life, comprising organisms such as animals, plants, fungi, and protists. These cells are distinguished from prokaryotic cells by their complex structure. Unlike prokaryotes, eukaryotic cells have a true nucleus which houses the cell's DNA. This nucleus is surrounded by a double membrane, isolating it from the rest of the cell's interior.
Some key features of eukaryotic cells include:

• Membrane-bound organelles: structures like mitochondria and golgi apparatus perform specific functions.
• Cytoskeleton: a network of fibers aiding in cell shape, organization, and transport of materials.
• Large and diverse: range from unicellular organisms like amoebas to multicellular organisms like humans.

Eukaryotic cells are essential for the advanced processes of life, from replication to movement. Their complexity allows them to form tissues and organs, enabling higher functions. Understanding these cells is crucial, as they form the basis of all complex life on Earth.

Amoeba movement

The amoeba, a single-celled organism, moves in a fascinating way using pseudopodia. These "false feet" are extensions of its cellular body that help it glide along surfaces. This movement is called amoeboid movement and is a slow, fluid motion.
The process behind this movement involves:

• Extension: The amoeba extends part of its body by pushing forward the cytoplasm.
• Attachment: As it extends, the pseudopodia attach to a new surface point.
• Contraction: The body then flows into the pseudopodia, pulling itself forward.

Amoebas move not only to find food but also to escape from predators. The use of pseudopodia for movement is a great example of how even simple organisms can interact efficiently with their environment, emphasizing the adaptability and resourcefulness of life.

Neutrophil function

Neutrophils are a type of white blood cell critical in the human immune response. They are the body's first line of defense against infections, especially bacterial invasions. Neutrophils use pseudopodia, similar to amoebas, to navigate through tissue spaces.
Their primary roles include:

• Phagocytosis: Engulfing and digesting bacteria and debris.
• Degranulation: Releasing enzymes to neutralize pathogens.
• Chemotaxis: Moving towards chemical signals emitted by infected or inflamed tissues.

Once an infection is detected, neutrophils are rapidly mobilized from the bloodstream, traveling to the site of infection. By forming pseudopodia, they can squeeze through tight spaces between cells in tissues, reaching areas where they're needed most. Understanding neutrophil functionality helps us appreciate the complexity and effectiveness of the immune system.

Protoplasmic streaming

Protoplasmic streaming, also known as cytoplasmic streaming, is the flow of cytoplasm within cells. This process is crucial for transporting nutrients, organelles, and other materials throughout the cell, especially in large cells like plant cells.
Key aspects of protoplasmic streaming include:

• Energy-driven: ATP provides energy for the movement.
• Actin-Myosin interactions: These proteins facilitate the flow by acting like tiny motors.
• Essential for growth: Affects distribution of materials needed for cell growth and division.

By continuously circulating internal components, cells maintain efficient metabolic processes and adapt quickly to changes in their environment. In amoeboid movement, protoplasmic streaming enables the cell to extend pseudopodia, highlighting how fundamental this process is to cellular movement and function.