Answer:
Genetic drift
Explanation:
Genetic drift can also be referred to as allelic drift, it refers to the variation in allelic frequencies within a particular population over a period of time. It can also be referred to as the random fluctuations in the number of genotypes within a population. Genetic drift is not influenced by the environment and is usually more pronounced in a small population of organisms.
For example, a population of birds can consist of green feathers and blue feathers with the green feathers as the dominant allele, but as a result of random fluctuations, the offspring may all be with green feathers and hence could eliminate or reduce the allele responsible for blue feathers over time.
<span>Essentially, cohesion and adhesion are the "stickiness" that water molecules have for each other and for other substances. You can see this in the picture to the right. The water drop is composed of water molecules that like to stick together, an example of the property of cohesion.</span>
Answer:
They are thick, strong and made up of thousands of tubulin which are spiral in shape.
Explanation:
In eukaryotic cells, they have microtubules which are fibres serving as tracks for cell to cell transport and regulate the shape of a cell.
Microtubules are different from other cytoskeletal filaments because they possesses a cylindrical shape with the tube having a larger diameter of 20-25 nm as compared to microfilament that have a diameter of 3-6 nm.
Microtubules are made of subunits of proteins called tubulin named alpha and beta that is not present in other cytoskeletal filaments.
C
As the cap helps it to move around while the tail prevents enzymes from eating the RNA
Answer:
<h2>A polyadenylation signal or poly(A)
</h2>
Explanation:
Termination. In eukaryotes, transcription is terminated differently for the all 3 different RNA polymerases. Transcription is terminated by two elements: i) a poly(A) signal and ii) a downstream terminator sequence.
In eukaryotic protein-encoding genes, the cleavage site in the RNA occurs between an upstream( the sequence before the cleavage site) AAUAAA and a downstream GU-rich, separated by approx 40-60 nucleotides. After they both have been transcribed, a protein knows as CPSF and another protein called CstF( in humans) helps in termination.
