Explanation

The prothallus of Nephrolepis (a type of fern) is haploid.

The prothallus is haploid, since it grew from a spore which had been formed by meiosis.

It does not have any vascular tissue and uses small rhizoids to anchor it to the ground.

On the underside of the prothallus the sex organs form.

Explanation

Borazine, also known as borazole, has the chemical formula B₃H₆N₃.

It is a compound that resembles benzene in structure but with alternating boron and nitrogen atoms in the ring, along with hydrogen atoms. 

Explanation

Osmium is the densest naturally occurring element, with a density of approximately 22.59 g/cm³.

This makes it the highest density transition element, far exceeding the densities of elements like mercury and zinc.

Explanation

When crossing CC (homozygous dominant) with Cc (heterozygous), the possible genotypes of the offspring are:

CC (from C and C)

Cc (from C and c)

The genotype distribution is:

CC: 50% (or 1/2)

Cc: 50% (or 1/2)

So, the proportion of homozygous dominant (CC) offspring is 1/2.

Explanation

The idea that characteristics acquired or lost during an organism's lifetime can be passed down to its descendants was proposed by Jean-Baptiste Lamarck.

This concept is part of Lamarck's theory of inheritance of acquired characteristics.

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

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.