Explanation

• Non-disjunction is the phenomenon where a pair of homologous chromosomes (or a pair of sister chromatids) fails to separate properly during meiosis.
• Resulting in an abnormal number of chromosomes in the daughter cells.
• This can lead to genetic abnormalities, such as Down syndrome (trisomy 21), or other chromosomal disorders.

Explanation

The outermost layer of the Sun is called the corona.

It is the Sun's outer atmosphere, extending millions of kilometers into space and visible during a total solar eclipse.

The innermost layer is the core, where nuclear fusion occurs.

Explanation

Leucocytes are also known as white blood cells.

They are colorless, irregularly shaped, nucleated cells that are larger in size compared to red blood cells (RBCs).

They play a vital role in the immune system, helping to fight infections and diseases.

Explanation

The G1 phase (Gap 1 phase) is the period of extensive metabolic activity in the cell cycle where the cell grows, enzymes are synthesized, and DNA is replicated.

This phase is also known as the interphase or the growth phase.

Explanation

Deductive reasoning is a type of logical reasoning that uses "if-then" statements to arrive at a conclusion.

It involves making a logical deduction based on a premise.

It is used in scientific reasoning to test hypotheses and predict outcomes.

Explanation

The scientific method is a systematic approach used to develop and test scientific knowledge, including in biology and other sciences. It involves:

• Observations
• Hypothesis formation
• Prediction
• Experimentation
• Data analysis
• Conclusion drawing

Explanation

The direction of induced e.m.f. (electromotive force) in a circuit is determined by Lenz's law.

It states that the induced e.m.f. will oppose the change in magnetic flux that induced it.

This is a consequence of the conservation of energy.

Explanation

Magnetic poles always exist in pairs, with every magnet having a north pole and a south pole.

Like poles (north-north or south-south) repel each other.

Unlike poles (north-south or south-north) attract each other.

Explanation

Electromagnetic waves are typically listed in order of increasing wavelength (or decreasing frequency) as follows:

• Gamma-rays (shortest wavelength, highest frequency)
• X-rays
• Microwaves (longer wavelength, lower frequency)

Explanation

Sound is a form of mechanical energy that is produced by vibrations or oscillations of particles in a medium, such as air, water, or solids.

When an object vibrates, it creates a disturbance in the medium around it, causing the particles to oscillate back and forth.

This oscillation, or wave motion, is what we perceive as sound.