Biology Test 343

Epithelial tissue covers the body surfaces and lines body cavities, playing key roles in protection, secretion, and absorption. It does not contribute to movement, which is the primary function of muscular tissue. An interesting fact about epithelial tissue is its ability to regenerate quickly, which is crucial for areas prone to wear and tear, such as the skin.

In a dihybrid cross involving two traits with complete dominance, Mendel's principles predict that the phenotypic ratio in the F2 generation will be 9:3:3:1. This ratio represents the distribution of the two traits in a 16-part grid, showing the combinations of dominant and recessive phenotypes.

The assertion accurately states that in pea plants, the allele for yellow seed color is dominant over the allele for green seed color. The reason is also true and correctly explains the assertion because plants with yellow seeds can have either a homozygous dominant (YY) or heterozygous (Yy) genotype, which is how dominance works in Mendelian genetics.

This allows vigorous growth of useful aerobic microbes into flocs (masses of bacteria associated with fungal filaments to form mesh like structures).

Once the BOD of sewage or waste water is reduced significantly, the effluent is then passed into a settling tank where the bacterial ‘flocs’ are allowed to sediment.

This sediment is called activated sludge.

The basic unit of classification is the species. A species is a group of organisms that can interbreed and produce fertile offspring under natural conditions. Species share fundamental similarities and are the most specific level of classification in the biological hierarchy. This concept is foundational in taxonomy, the science of naming, describing, and classifying organisms.

Platyhelminthes have soft and dorsoventrally flattened body with bilateral symmetry. Plasmodium and Trypanosoma belong to Phylum Protozoa while Wuchereria belongs to Phylum Aschelminthes.

The genus ranks directly above species in the taxonomic hierarchy. It groups together species that are closely related and share a common ancestor. For example, the genus Panthera includes big cats like lions (Panthera leo) and tigers (Panthera tigris), highlighting their close relationship.

Benthic organisms are bottom dwelling forms found crawling or attached to the bottom. The sediment characteristics often determine the type of benthic animals that can thrive there.

In the binomial nomenclature system, the second part of the name, 'leo' in Panthera leo, is the specific epithet and refers to the species. This system, developed by Carl Linnaeus, ensures each species has a unique, universally accepted scientific name comprising a genus name followed by a specific epithet.

Air passes from the external nares into the nasal cavity where the dust particles are trapped. From nasal cavity, the air moves into pharynx which is a short, vertical tube. It further leads into two tubes, trachea and oesophagus. Larynx is the upper part of trachea. Besides forming a part of the respiratory tract, it also serves as the voice box. Trachea is a thin walled tube that extends downward through the neck. It divides into two primary bronchi which on entering the lungs divide into fine branches called bronchioles which enter the alveoli. Exchange of gases occur in alveoli.