Explanation

• When red litmus paper is dipped in a basic solution, it turns blue.
• This indicates that the solution is basic, or alkaline.

Note: When blue litmus paper is dipped in an acid solution, it turns red.

Explanation

 The additional, small, circular, extrachromosomal piece of DNA in a bacterial cell is called a plasmid.

Structure: Small, double-stranded, circular DNA molecules.

Location: Found in the cytoplasm of bacteria (extrachromosomal).

Function: They typically contain non-essential but advantageous genes, such as those for antibiotic resistance.

Last updated 17-02-2026

Explanation

The SI is made up of 7 base units

that define the 22 derived units with special names and symbols, which are illustrated in NIST SP 1247, SI Base Units Relationship Poster. 

Explanation

• The electricity from a cell (such as a battery) is Direct Current (DC).
• It is the flow of electric charge in one direction only, without changing direction.
• This is the type of current used in electronic devices such as smartphones, laptops, and televisions.

Explanation

• A spacecraft is a man-made object designed to perform specific tasks in space.
• Such as exploration, communication, or research. 
• Examples of spacecraft include satellites, space stations, and probes.

Explanation

• A Spectroscope is used to identify the chemical elements present in a star and determine its composition.
• By analyzing the light spectrum, astronomers can also determine the star's temperature, velocity, and distance from Earth.

Explanation

• A spectrum of light is the distribution of light into its individual colours.
• Typically displayed in the order of red, orange, yellow, green, blue, indigo, and violet (ROYGBIV).
• This is often seen in the form of a rainbow or produced through the use of a prism.

Explanation

A refracting telescope has two lenses:

1. A primary lens (objective) that collects and focuses light.
2. A secondary lens (eyepiece) that magnifies the focused light to form an image.

Explanation

• Silicon is an example of a Semiconductor.
• Semiconductors like silicon have electrical conductivity between conductors and insulators.
• It enabling them to control electrical current flow in devices and integrated circuits.

Explanation

• The electricity used in homes and schools is typically Alternating Current (AC).
• It is the type of electric current that periodically changes direction.
• This is the type of current provided by power plants and distributed through the grid.