Problem 11 - Biology the Easy Way (E-Z Biology)

Question

Dried, ground stems of the horsetails are used in scouring powder because their cell walls contain (a) cutin (c) silica (b) cellulose (d) suberin

Step-by-Step Solution

Answer

Silica (c) makes horsetail stems useful in scouring powders.

Step 1: Understanding the Question

The question asks which compound found in the cell walls of horsetails makes them useful in scouring powders. Scouring powders are abrasive cleaners, suggesting that the compound should have abrasive properties.

Step 2: Analyzing the Options

Review each option to determine if they have abrasive properties: (a) Cutin - A waxy substance that forms waterproof barriers, not abrasive. (b) Cellulose - A component of plant cell walls, not inherently abrasive. (c) Silica - A hard, glass-like compound known for its abrasiveness. (d) Suberin - A fatty substance found in cork, not abrasive.

Step 3: Selecting the Correct Compound

Given the characteristics of each compound, silica (c) is the most likely to provide the abrasive quality needed for scouring powders.

Key Concepts

Plant Cell Walls

Plant cell walls are the rigid barriers surrounding the plant cells. They provide structure and protection to the cell. The main components of plant cell walls include cellulose, hemicellulose, and lignin.
Cellulose is the most abundant component, forming long chains that provide tensile strength. This means they help the plant cells maintain their shape, even when under pressure.
Cell walls are crucial for plant growth, as they allow them to stand upright, resist external pressures, and limit the entry of unwanted substances. In certain plants, like the horsetail, additional compounds can be found that give specific properties, such as abrasiveness, making them very useful in products like scouring powders. Cell walls do not just serve a structural function; they are also involved in filtering in and out what the plant needs or can do without.

• Support: Helps plant cells maintain shape and resist pressure
• Protection: Acts as a barrier to external threats
• Regulation: Controls the entry and exit of materials into and out of the cell

Scouring Powder Ingredients

Scouring powders are cleaning agents that help remove tough stains and grime. These products contain ingredients that are abrasive enough to scrub surfaces without causing damage.
A key ingredient in scouring powders is often silica. The abrasive nature of silica helps scrub away dirt and stains effectively.
Other common ingredients in scouring powders include:

• Baking soda: Acts as a mild abrasive while neutralizing odors
• Bleach: Provides disinfectant properties, killing germs on contact
• Limestone: Offers additional abrasiveness, enhancing cleaning power

These ingredients work together to create a balanced solution that is not only effective at cleaning but also safe for surfaces when used as directed. They achieve a balance between being abrasive enough to clean yet gentle enough to avoid scratching surfaces.

Abrasive Properties of Silica

Silica is a naturally occurring mineral known for its hardness and glass-like properties. This makes it an excellent abrasive material.
Its effectiveness as an abrasive material comes from its ability to scour surfaces and remove unwanted materials without too much effort. In cleaning products like scouring powders, silica plays a vital role in removing tough stains and grime.
Due to its strong, durable nature, silica can wear down surfaces gently, making it suitable for cleaning cookware, bathroom tiles, and even industrial machinery.

• Durable and hard: Ideal for tough cleaning tasks
• Versatile: Used in various cleaning products and industrial applications
• Non-toxic: Safe for use around the home

This explains why horsetails, whose cell walls contain silica, are used in traditional cleaning methods, leveraging their natural abrasive properties to great effect.