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Recessive
| What it's not: |
An adjective applied to cave-dwelling organisms; an adjective applied to right wing political parties, as in ‘recessive conservatives’. |
| What it is: |
The alleles of a gene are usually described as either The dominant or recessive. The recessive allele is generally the “weaker” allele and manifests only when two recessive alleles are found together. With eye colour, for example, blue eyes are found only when the person has no other colour alleles. In other words, the recessive allele is masked or overpowered by the dominant allele. |
Recombination
| What it's not: |
What can happen after one ‘breaks up’ with someone. |
| What it is: |
A process that ‘re-shuffles’ genes. This occurs in meiosis during ‘crossing over’ when both members of a chromosome pair exchange genetic information and during gamete (gametes are sex cells: sperm in males, eggs in females) formation when each gamete receives only one of each randomly re-shuffled chromosome pair. An organism’s DNA may also be manipulated by artificial means to produce recombinant DNA (rDNA). Another way to picture this is via Mr. Potato Head. Only eyes fit in the eyeholes but you can put in different eyes with a particular nose – you can even make Mr. into a Mrs. |
RFLP (Restriction Fragment Length Polymorphism)
| What it's not: |
The very short haircut worn by people who work in the military. |
| What it is: |
RFLP describes a size difference (length polymorphism) after DNA has been cut with restriction enzymes = one piece is a restriction fragment. Fragment sizes are affected by DNA sequence. If a restriction enzyme sees its target sequence, it will cut the DNA molecule. But if the target sequence isn’t there, the DNA won’t be cut and the fragment will consequently be longer. This characteristic has been important in creating lab tests for paternity and for DNA fingerprinting.
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Ribonucleic Acid (RNA)
| What it's not: |
A gasoline additive. |
| What it is: |
A nucleic acid that differs from DNA in two structural ways. 1) Instead of thymine as one of its bases, RNA uses uracil. 2) Instead of the sugar deoxyribose, it incorporates ribose. In terms of function, RNA does more ‘running around’ in the cell. For example, while DNA is content to be unzipped and read, messenger RNA (mRNA) takes a copy of genes in DNA out of the nucleus and assists in the manufacture of proteins by the ribosomes. As part of the protein-building process, a whole variety of different transfer RNAs (tRNA) bring the required amino acids to the required places so the particular protein can be built correctly. |
Ribosomal RNA (rRNA)
| What it's not: |
The most tender, succulent cut of beef.
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| What it is: |
rRNA molecules form a component of the ribosomes and associates with mRNA, tRNA and amnio acids during translation.
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Ribosome
| What it's not: |
One of the B-complex vitamins. |
| What it is: |
Protein
synthesis occurs in the ribosome. It is a huge complex of proteins and
RNA that converts the information from RNA into an amino acid sequence:
that is, it translates the mRNA sequence into protein. The ribosome is
one of the first complexes (i.e. proteomes) to be studied in detail and
the more it is studied, the more proteins and RNA we find are involved! |
Risk
| What it's not: |
Otherwise known as a blind date |
| What it is: |
Risk is the probability of a negative event occurring. For example, women have a 12% risk of developing breast cancer over their lifetime. The perception of risk can vary between different people. With our example, some people might think 12% is a low risk where as others might think it is a high risk.
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