Explanation

A hypothesis is a testable, tentative explanation for a biological problem, based on initial observations.

It guides experiments and is later validated or refuted.

Explanation

Intelligence tests assess higher-order thinking skills, including problem-solving, analysis, and adaptability.

They go beyond rote knowledge (unlike achievement tests) to measure cognitive abilities.

Explanation

In the sentence, 'light' describes the noun 'affair', showing it's not serious—hence, it's an adjective.

Adjectives modify nouns to give more information about their quality or nature.

Explanation

Detritus food chain starts with dead organic matter (detritus), including decaying plant material.

Decomposers (like fungi, bacteria) and detritivores (like earthworms) feed on this material, converting it into simpler substances.

Explanation

In this reaction, element C displaces B from compound AB, forming A + BC.

Such reactions are classified as single displacement or single replacement reactions.

Explanation

Lactobacillus bulgaricus is a lactic acid bacterium used primarily in the fermentation of milk to produce yogurt.

It works alongside Streptococcus thermophilus to convert lactose into lactic acid, giving yogurt its texture and tangy flavor.

Explanation

Loudness is how the intensity of a sound is perceived by the human ear.

Greater intensity → louder sound.

It is measured in decibels (dB).

Explanation

To determine the type of conic section, rewrite the equation in standard form:

9x² + 4y² = 36

Divide by 36:

x²/4 + y²/9 = 1

Since 9 > 4, the major axis is vertical.

Explanation

The ratio test and root test are inconclusive when the limit of the ratio (or root) of successive terms is exactly 1.

These tests fail to determine convergence or divergence in this case.

Explanation

Given the product of two complex numbers (x + iy) and (x' + iy') is zero:

(x + iy)(x' + iy') = 0

This implies either (x + iy) = 0 or (x' + iy') = 0.

Therefore, at least one of the complex numbers must be zero.