Explanation

 Tactile signals:

Involve the transmission of information through physical touch or contact. 

Examples of tactile signals:

Mating: Tactile signals play a role in courtship and mating rituals, like honeybee foraging through touch. 

Explanation

 Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota

The one extant family, the Manidae, has three genera: Manis, Phataginus, and Smutsia.

Domain: Eukaryota

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Mirorder: Ferae

Clade: Pholidotamorpha

Order: Pholidota

Weber, 1904

Explanation

The burning of fossil fuels has several disadvantages:

A. Release of Harmful Gases: It emits pollutants like carbon monoxide, sulfur dioxide, nitrogen oxides, and particulate matter, contributing to air pollution and health issues.

B. Oxygen Consumption: Combustion requires oxygen, as fossil fuels react with it to produce energy and byproducts.

C. Carbon Dioxide Emission: It releases significant amounts of carbon dioxide, a major greenhouse gas driving climate change and global warming.

Explanation

Seahorse is a true fish; it has gills, fins, and lives in water.

Jellyfish, cuttlefish, and starfish are not true fish despite their names.

Explanation

Spiral cleavage is characterized by diagonal cleavage planes that are not symmetrical between the poles, resulting in unequal blastomeres arranged in a spiral pattern.

Determinate cleavage means that the fate of each blastomere is predetermined early on, meaning each cell has a specific developmental role. 

Explanation

The embryological stages of all vertebrates show similarities in anatomical features, reflecting a common evolutionary origin.

Explanation

Parvoviruses are among the smallest DNA viruses, with a typical diameter of around 18–26 nanometers (nm).

So, 20 nm is the most accurate option from your list.

Explanation

The hypothalamus is a part of the brain that acts as the body's thermostat, regulating body temperature by adjusting heat production and heat loss to maintain a stable core temperature. 

Explanation

Explanation

The mantle is a feature of mussels and other mollusks, responsible for secreting the shell.