Cell Biology

Pluripotent stem cells have the ability to differentiate into any cell type derived from the three primary germ layers: ectoderm, mesoderm, and endoderm. This means they can give rise to nearly all cell types in the body, but not extra-embryonic tissues like the placenta.
- Totipotent stem cells (e.g., zygote) can give rise to all embryonic and extra-embryonic cells.
- Multipotent stem cells can differentiate into a limited range of cells within a specific germ layer.
- Unipotent stem cells can give rise to only one specific cell type.
Thus, the correct answer is pluripotent stem cells.

Both statements are true — in cellular level organisms like sponges, specialized sensory and nerve cells are absent, leading to functional isolation.

Monocytes are large agranulocytes with a kidney-shaped nucleus and are phagocytic in function.

Totipotent stem cells (e.g., zygote) can give rise to all cell types.
Pluripotent stem cells (e.g., inner cell mass of blastocyst) can form almost any cell but not placenta.
Multipotent stem cells (e.g., haemopoietic stem cells) can form multiple types of cells within a specific tissue.
Unipotent cells (e.g., basophil progenitor cells) can only develop into one cell type.

Step 1: Understand the question.
The question asks to identify the correct statements regarding different types of flagella (flagellae) based on their structure. Step 2: Evaluate each statement based on the known characteristics of flagella types. \begin{itemize} \item Statement I: Stichonematic flagellae possess a single row of lateral appendages.
Stichonematic flagella are characterized by the presence of a single row of fine, hair-like lateral appendages (also known as mastigonemes or flimmer hairs) on one side of the flagellum. This statement is Correct. \item Statement II: Pantonematic flagellae are completely devoid of mastigonemes.
Pantonematic flagella are characterized by having two or more rows of mastigonemes (lateral appendages) distributed all around the flagellum. Flagella completely devoid of mastigonemes are typically called whiplash or acronematic flagella. Therefore, this statement is Incorrect. \item Statement III: Acronematic flagellae have a naked terminal part of the axoneme.
Acronematic flagella (also known as whiplash flagella) are smooth, lacking lateral appendages. They often taper into a naked (uncovered by mastigonemes or extensions of the flagellar membrane) terminal filament, which is an extension of the axoneme. This statement is Correct. \item Statement IV: Pantacronematic flagellae are completely devoid of terminal naked filament.
Pantacronematic flagella are a type of pantonematic flagella (having multiple rows of mastigonemes) that also possess a terminal naked filament, similar to acronematic flagella. The statement claims they are completely devoid of it, which is contrary to their definition. Therefore, this statement is Incorrect. \end{itemize} Step 3: Identify the correct option based on the evaluation.
Based on the analysis, statements I and III are correct, while statements II and IV are incorrect. The option that includes both I and III is the correct one. The final answer is .