Biology Chapter: Unicellular Organisms

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Questions and Answers

What method does Amoeba sp. use to move in response to obstacles?

Extending pseudopodia (correct)

Flapping cilia

Contracting its cell membrane

Rolling in a spiral motion

Which of the following processes do unicellular organisms perform to maintain life?

Internal digestion and organ formation

Hormonal regulation and multicellular support

Respiration and excretion (correct)

Photosynthesis and complex behaviors

How do Paramecium sp. primarily achieve movement?

By contracting and relaxing their membranes

Establishing a flagellar propulsion

Pseudopodia extension like Amoeba

Using rhythmic ciliary beats (correct)

In responding to stimuli, what is a common response of both Amoeba sp. and Paramecium sp.?

They move away from the stimuli Signup and view all the answers

Which characteristic defines unicellular organisms in comparison to multicellular organisms?

Capability to fulfill all life functions with one cell Signup and view all the answers

What is the primary role of chlorophyll in chloroplasts?

To absorb sunlight and help in photosynthesis Signup and view all the answers

What is the main difference in the vacuole structure between young and mature plant cells?

Mature cells contain a large vacuole while young cells have many small vacuoles Signup and view all the answers

What component of the plant cell membrane is responsible for its rigidity?

Cell wall made from cellulose fibers Signup and view all the answers

What best describes the function of the cytoplasm in plant cells?

It serves as a medium for biochemical reactions Signup and view all the answers

During osmoregulation in unicellular animals, what is the primary function of the vacuole?

To contract and regulate water levels Signup and view all the answers

What is the primary function of the rough endoplasmic reticulum?

Transport of proteins synthesized by ribosomes Signup and view all the answers

Which characteristic differentiates the smooth endoplasmic reticulum from the rough endoplasmic reticulum?

Synthesis of glycerol and lipids Signup and view all the answers

How does the structure of the endoplasmic reticulum facilitate its function?

The flattened sacs provide a large surface area for biochemical reactions Signup and view all the answers

What role does the smooth endoplasmic reticulum play in drug metabolism?

It carries out detoxification of drugs and metabolic by-products Signup and view all the answers

Which component of the cell is responsible for determining cell characteristics and metabolic function?

Chromosomes containing DNA Signup and view all the answers

What triggers sexual reproduction in Paramecium sp.?

Unfavorable environmental conditions Signup and view all the answers

Which structure in Paramecium sp. is primarily responsible for expelling excess water?

Contractile vacuole Signup and view all the answers

How does Amoeba sp. move?

Through pseudopodia Signup and view all the answers

What would most likely happen to the contractile vacuole of Paramecium sp. in a concentrated salt solution?

It would collapse and cease functioning Signup and view all the answers

What is the significance of the oral groove in Paramecium sp.?

It is involved in food intake Signup and view all the answers

Study Notes

Cell Biology and Organisation

This chapter covers cell structure, function, and organisation in both unicellular and multicellular organisms.
It examines different levels of organisation, starting with cells, then tissues, organs, and ultimately, organ systems.

Cell Structure and Function

Animal and plant cells are composed of various organelles with specific functions.
The organelles include the nucleus, mitochondria, endoplasmic reticulum (rough and smooth), Golgi apparatus, ribosomes, lysosomes, vacuoles, chloroplasts, and the cell membrane.
The functions of each cell component are closely linked to its structure and density within the cell.

Living Processes in Unicellular Organisms

Unicellular organisms (e.g., Amoeba, Paramecium) carry out all fundamental life processes.
Key processes include movement (e.g., pseudopodia in Amoeba, cilia in Paramecium), responding to stimuli, nutrition (phagocytosis, food vacuoles), respiration (simple diffusion), excretion (osmoregulation), and reproduction (binary fission).

Living Processes in Multicellular Organisms

Multicellular organisms comprise specialized cells with specific structures related to functions.
Examples include muscle cells for movement, nerve cells for transmitting signals, and epithelial cells for covering surfaces. Function and structure are intricately linked.

Levels of Organisation in Multicellular Organisms

Complex organisms exhibit multiple levels of organization based on similar structures and functions. The hierarchy starts with cells followed by tissues, organs, and organ systems.
The integration of different tissues to form organs is essential for particular functions.

Tissue Organisation in Plants

Plant tissues are organised in a manner similar to that of animals, but with different types of tissues (e.g., meristematic, permanent).
Plant tissues often play roles such as storing materials, providing support, or conducting processes like photosynthesis.

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Description

Test your knowledge on the characteristics and functions of unicellular organisms such as Amoeba and Paramecium. This quiz covers topics from their movement, responses to stimuli, and cellular structures crucial for maintaining life. Challenge yourself and see how well you understand these fascinating life forms!