Explanation

Ray-finned fishes are present in the class Osteichthyes.

This class is characterized by having a skeleton made of bone and includes the vast majority of fish species.

Explanation

The statement that tropical rainforests accumulate more organic matter on the forest floor than temperate grasslands is incorrect.

In reality, the decomposition rate in tropical rainforests is so rapid due to high temperatures and humidity that organic matter does not accumulate significantly on the forest floor.

In contrast, temperate grasslands may accumulate more organic matter over time due to slower decomposition rates caused by cooler temperatures and seasonal variations.

Explanation

Soil pollution can be caused by various factors including acid rain, ozone, and aerosols.

Explanation

Alkali metals (such as lithium, sodium, potassium, etc.) act as reducing agents.

They readily lose their single valence electron to form positive ions, which means they donate electrons in reactions

Explanation

The notochord is a flexible, rod-shaped structure that is present during the embryonic stage of all chordates

It provides support and defines the primitive axis of the body.

This characteristic is a key feature that distinguishes chordates from non-chordates.

Explanation

Kangaroos belong to the infraclass Metatheria, which includes all marsupials.

Metatherians are mammals that give birth to relatively undeveloped young

they are mostly found in Australia and the Americas.

Explanation

Mitosis is a type of cell division that results in two daughter cells, each with the same number of chromosomes as the parent cell, producing somatic cells (body cells).

It is responsible for:

• growth
• repair
• asexual reproduction in organisms.
  

Explanation

Calcitonin is produced and secreted by the parafollicular cells (or C cells) of the thyroid gland

Its primary function is to lower blood calcium levels by inhibiting osteoclast activity in bones, which reduces bone resorption, and by increasing calcium excretion in the kidneys.

This action helps to maintain calcium homeostasis in the body.

Explanation

Sodium hypochlorite (NaClO), usually as a 3–6% solution in water

It is usually called "liquid bleach" or just "bleach"

Sodium hypochlorite acts as a powerful disinfectant and stain remover, making it effective for various cleaning and sanitizing purposes.

Explanation

Near Earth's surface, the acceleration due to gravity is 9.8 m/s2 (32 ft/s2).

This means that, ignoring the effects of air resistance,

the speed of an object falling freely will increase by about 9.8 meters per second (32 ft/s) every second.