Biology Test 332

The separated DNA fragments can be visualised only after staining the DNA with Ethidium bromide followed by exposure to UV radiation.

The Human Genome Project revealed that humans have fewer genes than previously thought, with the number being less than 25,000. This discovery has implications for our understanding of genetics and the complexity of human biology.

Restriction enzymes do not function by inspecting the length of a DNA sequence. Instead, they recognize and cut specific nucleotide sequences, known as recognition sites, within the DNA molecule. These recognition sites are often palindromic, meaning they read the same sequence of nucleotides in the forward and reverse direction. The resulting DNA fragments, which can have sticky or blunt ends, are then used in genetic engineering and can be joined together using DNA ligases.

The Coelacanth is considered a transitional form between fish and amphibians. Initially thought to have gone extinct around 66 million years ago, living specimens were discovered in 1938. Coelacanths possess lobed fins that resemble the limbs of terrestrial animals, suggesting a link between aquatic and terrestrial life forms. This discovery provided significant insight into the evolutionary transition from water to land habitats.

Because ori sequence is responsible for controlling the copy number of the linked DNA in the vector. Ori i.e. origin of replication is responsible for initiation of replication

Adaptive radiation is the process by which a single species evolves into multiple species to fill various ecological niches within its environment. This evolutionary phenomenon often occurs when a species colonizes a new habitat with diverse conditions, leading to the evolution of distinct forms that can exploit different resources. Darwin's finches in the Galapagos Islands are a classic example of adaptive radiation, where a single ancestral species gave rise to multiple species with varied beak shapes and sizes, each adapted to different food sources.

Selectable marker is a gene introduced into a cell, especially a bacterium or to cells in culture that confers a trait suitable for artificial selection.

Selectable markers help in identification and elimination of non-transformants whilst permitting selective growth of transformants.

Note: Selectable marker genes are conditionally dominant genes that confer an ability to grow in the presence of applied selective agents that are normally toxic to plant cells or inhibitory to plant growth, such as antibiotics and herbicides. Genes that are frequently used to select transformed plant tissues include nptII, hpt, bar, and gox, that confer resistance to kanamycin, hygromycin, phosphinothricin,and glyphosate, respectively. Commonly used selectable marker systems include neomycin phosphotransferase, hygromycin phosphotransferase, phosphoinothricin acetyltransferase, and glyphosate oxidoreductase.

Blood is indeed classified as a connective tissue because of its role in connecting different parts of the body by transporting essential substances. Its liquid matrix, plasma, allows it to flow through blood vessels, reaching various tissues and organs.

Restriction enzymes belong to a larger class of enzymes called nucleases. Nucleases are of two different kinds: exonucleases (which remove nucleotides from the end of a DNA molecule) and endonucleases (which break internal phosphodiester bonds at palindromic sites that are highly specific).

DNA ligase helps in ligating/joining DNA fragments. Proteases is an enzyme which breaks down proteins and peptides

While it's true that cardiac muscles are involuntary and are designed to work without fatigue, their resistance to fatigue is due to their rich supply of mitochondria, not their ability to generate their own electrical impulses. The presence of mitochondria provides a continuous supply of energy.