Explanation

The chimera, also known as a ghost shark or ratfish, belongs to the class Holocephali.

This class is distinct from other cartilaginous fish like sharks and rays

It is characterized by having a:

• single gill cover
• a tooth structure adapted for crushing
• a lack of a spiracle
  

Explanation

• Drosophila melanogaster is favored in classical genetics research
• Because of its short life cycle, which allows for rapid generation of experimental results.
• Its easy handling in the laboratory makes it practical for large-scale genetic studies.
• Additionally, obvious characteristics such as distinct eye colors and wing shapes make it easier to observe and analyze genetic variations and inheritance patterns.
• These attributes make Drosophila an ideal model organism for studying fundamental genetic principles.
  

Explanation

The Adventures of Tom Sawyer is a novel written by Mark Twain, 

The book was first published in 1876

It is a classic of American literature, depicting the adventures of a young boy named Tom Sawyer 

Explanation

The capital and largest city is Algiers, located in the far north on the Mediterranean coast.

Explanation

• The term "Learning" refers to the process of acquiring new knowledge, skills, or behaviors as a result of experience.
• When there is a permanent change in behavior due to these experiences, it is considered learning.
• Learning can occur through various methods such as observation, instruction, practice, or personal discovery, leading to a lasting modification in behavior or understanding.

Explanation

When crossing an organism with genotype Aa (heterozygous) with one that has genotype aa (homozygous recessive), the offspring can inherit either the A or a allele from the Aa parent and only the a allele from the aa parent.

This results in a 1:1 ratio of genotypes, with half of the offspring being Aa (heterozygous) and the other half being aa (homozygous recessive).

The incorrect ratio of "1/2 Az & 1/2 aa" mentioned in the question is likely a typo.

Explanation

Carbon dioxide (CO₂) is the gas used to carbonate beverages.

It dissolves in the liquid under pressure, creating bubbles and giving the drink its characteristic fizz.

Explanation

Excessive irrigation can lead to the accumulation of salts in the soil, causing salinity.

Salinity causes salt stress in plants.

Prolonged liberal irrigation results in nutrient depletion in the soil so that the plants do not grow properly.

Explanation

In the complex  [ 𝐹 𝑒 ( 𝑁 𝐻 3 ) 6 ] ^2 + , iron (Fe) is in the +2 oxidation state, meaning it has a  𝑑6 electron configuration.

Ammonia (NH₃) is considered a strong field ligand under Crystal Field Theory (CFT), causing the electrons in the 𝑑-orbitals to pair up due to the large splitting of the 

𝑑-orbitals.

In a strong field environment, the electrons occupy the lower energy  𝑡2𝑔 orbitals first, and all six electrons pair up, leaving no unpaired electrons.

Therefore, the number of unpaired electrons is 0.

Explanation

Horny structures, like the horns of cattle, are made of keratin and do not shed off.

Unlike antlers, which are shed annually, horns are permanent structures that continue to grow throughout the animal's life

The other options—scales, feathers, and fur—are either shed or replaced regularly.