Structure of DNA, Key genetic terms and transcription

Question 1

What is a Genotype? What is a Phenotype?

Answer 1

A Genotype is the particular Alleles that a person has inherited for a certain gene

A Phenotype is the physical expression of that Genotype

Question 2

What is the function and structure of DNA

Answer 2

(deoxyribonucleic acid): found in the nucleus of all body cells and is the genetic material coding for the structure and function of the human body. DNA:

-replicates itself for cell division

-provides the basic instruction (blueprint) for building every protein in the body (protein synthesis)

-is composed of two chains of nucleotides containing the bases A, G, C, and T

-and it is arranged in a double helix due to the bonding of the nucleotide bases of one chain to the other via the following combinations: A binds with T; G binds with C

Question 3

What is the central dogma of biology

Answer 3

The central dogma of biology is simply put, the steps that occur in order for DNA to eventually create a protein and the steps are as follows

1) DNA is replicated
2) The replicated DNA is transcribed onto a strain of mRNA
3) the information is then translated into 3 base pairs of A,U,G and C
4) those 3 base pairs (codons) code for polypeptides that in turn create proteins

Question 4

DNA and RNA

Answer 4

DNA and RNA molecules have different functions. DNA stores genetic information for the cell, whereas RNA codes for amino acids and acts as a messenger between DNA molecules and the ribosomes

Question 5

Define the following terms (sugar-phosphate backbone, chromosome, chromatid, locus, tRNA, gene product

Answer 5

Sugar-Phosphate backbone: The ‘sides’ of the ladder (or strands of DNA) are known as the sugar-phosphate backbone. This backbone consists of alternating phosphate and sugar groups, with the sugar molecule of one nucleotide linking to the phosphate group of the adjacent nucleotide.

Chromosomes: Chromosomes are long DNA molecules with part or all of the genetic material of an organism.

Chromatids: A chromatid is one of the two identical halves of a chromosome that has been replicated in preparation for cell division. The two “sister” chromatids are joined at a constricted region of the chromosome called the centromere.

Locus: A genes locus is where on the chromosome it is located

tRNA: is a type of RNA molecule that helps decode a messenger RNA (mRNA) sequence into a protein. tRNAs function at specific sites in the ribosome during translation, which is a process that synthesizes a protein from an mRNA molecule.

gene product: The protein, resulting from the expression of a gene. A measurement of the amount of gene product is sometimes used to infer how active a gene is.