Bio Exam
Codominant traits exist when two different alleles for a genetic trait such as flower colour, and hair texture are both expressed. The expression of codominance infers a relationship between two types of a gene. In codominance, the phenotypes of both alleles inherited from the parents are expressed ("Codominance - Glossary Entry", 2016).
Genetic expression feather colors in purple penguin ("Basic Principles of Genetics: Probability of Inheritance", 2016).
With the order of dominance as pd>pm>pl>pvl a 1 dark: 1 medium ration of phenotype among the baby penguins is expected.
Marfan Syndrome is a genetic disorder that exhibits variation among affected individuals. The range of phenotypic severities is an example of variable expressivity. Variable expressivity is caused by the combination of genetic, environmental and lifestyle factors ("What are reduced penetrance and variable expressivity?", 2016).
The heterokaryon composed of double mutant nuclei that would grow on minimal media are heterokaryon of 1,3, & 1, 2 and lastly 2,3. These mutants would thrive in minimal media because they genetically possess the ability to break down essential nutrients for growth("One gene makes one protein: DNA from the Beginning", 2016).
Epistatic genes determine the expression of a trait (whether a trait is expressed or not). The gene C by blocking the effects of gene B at other locus acts as an epistatic gene ("epistatic gene | genetics", 2016).
Nucleotides are characterized by three essential components, a nitrogenous base, a pentose sugar and a phosphate group. The nitrogenous bases are either pyrimidine or purines and are attached to 1' carbon of the pentose sugar. Carbon atoms of sugar are numbered starting at the end of the chain nearest the carboxyl group (Nelson, Lehninger & Cox, 2008).
Adjacent nucleotides in DNA and RNA are covalently bonded through phosphate groups. The 5’-hydroxyl group of RNA nucleotide is joined to the adjacent 3’-hydroxyl group of the next RNA nucleotide through phosphodiester bonds (Nelson, Lehninger & Cox, 2008).
In the transcription of prokaryotes such as E. Coli the formation of RNA hairpin and numerous uracil nucleotides plays a crucial role in the release of the transcript and polymerase at the termination site. This is a critical mechanism for the termination of transcription (von Hippel & Wilson, 1995).
A codon is a sequence of 3 nucleotides that specifies for an amino acid. The first base of a codon (5’3’)pairs with the third base of the anticodon and the codon-anticodon recognition of RNA happens in the decoding center (Koch, 2016).
A kinase is an enzyme that catalyzes the transfer terminal phosphate group to an acceptor such as amino acids. The phosphorylation of amino acid groups (such are serine) of some proteins by kinase alters the protein's enzymatic activity(Nelson, Lehninger & Cox, 2008).
A ribozyme is an RNA enzyme that functions by catalyzing a chemical reaction in a similar manner to protein enzymes. This enzyme is also called catalytic RNA and is found in the ribosome where it plays a role in RNA splicing and tRNA synthesis (Nelson, Lehninger & Cox, 2008).
Translation is a method of decoding genes and working backwards from tRNA anticodon nucleotides it reveals that the template strand is line 2 with a 3’ to 5’ polarity from left to right.
Translation of genetic material is carried out by mRNA and begins at the initiation codon also called the start codon. The initiation codon (usually AUG) marks the proper start point for mRNA to identify and initiate the translation process (Nelson, Lehninger & Cox, 2008).
Translation occurs cotranscriptionally only in prokaryotes. Cotranscription can be defined as the simultaneous transcription of more than one gene. The lack of a nucleus enclosed in a membrane enables prokaryotes to perform function cotranscriptionally.
The biological role of a protein is determined by its 3-dimensional shape and the arrangement of the amino acids within the protein. Proteins that facilitate the folding of synthesized protein are called polypeptide chains called chaperones (Nelson, Lehninger & Cox, 2008).
References
Basic Principles of Genetics: Probability of Inheritance. (2016). Anthro.palomar.edu. Retrieved
5 April 2016, from http://anthro.palomar.edu/mendel/mendel_2.htm
Codominance - Glossary Entry. (2016). Genetics Home Reference. Retrieved 5 April 2016, from
https://ghr.nlm.nih.gov/glossary=codominance
Epistatic gene | genetics. (2016). Encyclopedia Britannica. Retrieved 5 April 2016, from
http://www.britannica.com/science/epistatic-gene
Koch, A. Codon Recognition: How tRNA and Anticodons Interpret the Genetic Code (2016).
Study.com. Retrieved 5 April 2016, from http://study.com/academy/lesson/codon- recognition-how-trna-and-anticodons-interpret-the-genetic-code.html
Nelson, D., Lehninger, A., & Cox, M. (2008). Lehninger principles of biochemistry. New York:
W.H. Freeman.
One gene makes one protein:: DNA from the Beginning. (2016). Dnaftb.org. Retrieved 5 April
2016, from http://dnaftb.org/16/
Von Hippel, P., & Wilson, K. (1995). Transcription termination at intrinsic terminators: the role
of the RNA hairpin. Proceedings Of The National Academy Of Sciences Of The United States Of America, 92(19), 8793. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC41053/
What are reduced penetrance and variable expressivity?. (2016). Genetics Home Reference.
Retrieved 5 April 2016, from https://ghr.nlm.nih.gov/handbook/inheritance/penetranceexpressivity
