Biology Chapter: Organisation of the Organism

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Questions and Answers

What is a defining characteristic of plant cells?

Presence of chloroplasts and a cell wall (correct)

Presence of small vacuoles

Presence of lysosomes

Absence of any vacuoles

Which of the following statements about animal cells is correct?

They contain cell walls made of cellulose.

They have large vacuoles.

They are characterized by small vacuoles or vesicles. (correct)

They perform photosynthesis.

What is the primary function of chloroplasts in plant cells?

Movement of molecules

Photosynthesis and energy conversion (correct)

Support and protection

Cell division

What role does the cell wall play in plant cells?

Protection and support Signup and view all the answers

How is magnification calculated?

Image size divided by actual size Signup and view all the answers

What is the primary function of methylene blue dye in preparing human cheek cells?

To make the cell nuclei more visible Signup and view all the answers

Which step should be performed first when preparing a slide with human cheek cells?

Rinse your mouth with water Signup and view all the answers

What precaution should be taken while lowering the coverslip over the cheek cell sample?

Gently lower to avoid trapping air bubbles Signup and view all the answers

When using a microscope, which objective lens should be selected first?

Lowest power objective lens Signup and view all the answers

What color will iodine stain cell nuclei?

Pale yellow Signup and view all the answers

What is the primary function of the mitochondria in both plant and animal cells?

Site of aerobic respiration Signup and view all the answers

Which structure is found in plant cells but not in animal cells?

Chloroplasts Signup and view all the answers

What is the function of the vacuole in plant cells?

Support cell and maintain firmness Signup and view all the answers

Which of the following structures controls the activities of the cell?

Nucleus Signup and view all the answers

Which component of the cell membrane controls what enters or leaves the cell?

Partially permeable membrane Signup and view all the answers

What is typically true about the sap vacuole in plant cells compared to animal cells?

It is large and permanent Signup and view all the answers

What structure is primarily responsible for protein synthesis?

Ribosomes Signup and view all the answers

Which of the following is NOT a similarity between plant and animal cells?

Chloroplasts Signup and view all the answers

What is the primary function of root hair cells?

Absorption of water and minerals Signup and view all the answers

Which statement describes xylem vessels?

They conduct water and minerals and provide support. Signup and view all the answers

How are root hair cells adapted for their function?

They have a large concentrated sap vacuole. Signup and view all the answers

What modification allows xylem vessels to support the plant effectively?

Lignified walls that provide rigidity and impermeability. Signup and view all the answers

Which of the following is NOT a characteristic of a modified cell?

Typical form for generic functions Signup and view all the answers

What role does the finger-like projection of root hair cells serve?

To increase surface area for absorption. Signup and view all the answers

In terms of organization, what level does 'tissue' refer to?

A group of similar cells working together. Signup and view all the answers

What system is formed by a group of organs with closely related functions?

Organ System Signup and view all the answers

What is a primary adaptation of muscle cells that allows them to perform their function effectively?

Ability to respire anaerobically Signup and view all the answers

Which structure in muscle cells is modified to aid in contraction?

Contractile filaments Signup and view all the answers

What feature do red blood cells lack that differentiates them from other cell types?

Nuclei Signup and view all the answers

What is the purpose of using iodine solution when preparing a slide of onion epidermis cells?

To stain starch in the cells Signup and view all the answers

What is the correct method for lowering the cover-slip onto the onion tissue during slide preparation?

Lower it at an angle of about 45° Signup and view all the answers

How do muscle cells ensure they have enough energy for their functions?

By storing carbohydrates as glycogen Signup and view all the answers

What specific safety measure must be taken while doing dissections in practical work?

Take care when using a scalpel Signup and view all the answers

What does the term 'magnification' refer to in microscopy?

How many times the image is larger than the object Signup and view all the answers

Study Notes

Organisation of the Organism

Living organisms are made up of many cells
Cells are the fundamental units of living organisms
Plant cells have chloroplasts, cell walls, and large vacuoles
Animal cells have small vacuoles or vesicles
Some cells are modified, including root hairs, muscle fibers, and xylem tissue
Magnification is calculated by dividing the image size by the actual size

Cell Structure and Organization

Plant Cell Structures
- Cell wall: Found only in plant cells, made of cellulose (non-living), supports and protects, and gives the cell shape
- Chloroplasts: Contain chlorophyll, traps light energy, convert it to chemical energy for photosynthesis, to form starch
- Vacuole: Fluid filled, surrounded by a membrane, contains salt and minerals, support and keep the cell firm.
Structures found in both plant and animal cells
- Cytoplasm: Jelly-like substance with particles and organelles.
- Cell membrane: Partially permeable membrane, controls what enters and leaves cell, site of chemical reactions
- Mitochondria: Oval-shaped organelle, responsible for aerobic respiration
- Nucleus: Circular shape that contains DNA, controlling cell division and activity
- Ribosomes: Circular structure attached to the cell membrane, responsible for protein synthesis
Animal Cell
- The text describes animal cells and their various structures and functions that enable them to perform their roles.

Similarities and Differences Between Plant and Animal Cells

Similarities: Both have cell membranes, cytoplasm, nuclei, and mitochondria
Differences:
- Plant cells have cell walls and large, permanent vacuoles; animal cells do not
- Plant cells usually have chloroplasts; animal cells do not
- Plant cells typically store starch; animal cells typically store glycogen

Levels of Organization

Cell: The basic structural and functional unit of all organisms
Tissue: Groups of similar cells that perform a specific function
Organ: Groups of tissues that perform a specific function
Organ system: Groups of organs that work together to perform a particular function

Modified Cells

Modification: Change in shape or structure to adapt to a specific function
Modified cells perform specialized functions different from their original roles
Examples of modified cells
- Root hair cells: Absorbs water and minerals
  - Large number and finger-like projections to maximize surface area,
  - Contains mitochondria for energy production,
  - Large vacuoles for water absorption,
  - Excrete viscous substances for water absorption and protection against soil particles.
- Xylem Vessels: Conducts water and minerals
  - Fine tubes for capillary action,
  - Lignified walls for support, and impermeability to water
  - Absence of cross-walls, cytoplasm, and nuclei to minimize resistance to water flow,
  - Pits for water and mineral distribution
Muscle cells: Specialized cells for contraction in movement
- Contains many mitochondria for producing energy
- Stores carbohydrates in the form of glycogen
- Part of cytoplasm is modified for contractile filaments

Practical work: Preparing Slides

Safety precautions for handling equipment and materials
Plant cell preparation
- Preparing onion epidermis cells and staining them with iodine to view cell structures clearly. Steps include peeling an onion layer, placing it on a slide, adding iodine solution, covering with a cover slip, observing under the microscope
Animal cell preparation
- Preparing cheek cells, staining with methylene blue to color nuclei, viewing under a microscope. Steps include rinsing your mouth, collecting cheek cells with a cotton bud, placing the sample on a slide, adding dye, placing the cover slip, and observing під microscope

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Description

Explore the fascinating structure and organization of cells in living organisms. This quiz covers key concepts related to plant and animal cell features, magnification calculations, and cellular functions. Test your knowledge on the fundamental units that compose life and their unique structures.