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Candidate gene
| What it's not: |
What all aspiring politicians hope they have |
| What it is: |
A gene located in the chromosome region suspected to cause or contribute to a disease. The gene’s function and place of action should suggest a role in the disease in question. For example, the gene coding for a protein that works in the brain and regulates brain transmitters is a good candidate for depression. |
Cell
| What it's not: |
A growth on a teenager’s ear |
| What it is: |
The smallest, membrane-surrounded dollop of diversified matter capable of independent existence. We humans are walking, talking communities made up of billions of them. With the exception of viruses and prions, all living organisms are made up of one or more of these little powerhouses. |
Centromere
| What it's not: |
A lake in Central Park |
| What it is: |
When peered at through a microscope, the centromere looks like a cinched-in waist in the chromosome. During cell division, the centromere determines how chromosomes pair up and divide. It is, in fact, the “nerve centre” of the chromosome, directing cell movement during meiosis and mitosis. If the centromere is lost (i.e. chromosome breaks), that portion of DNA without a centromere is lost because it can’t find its way during cell division. Occasionally, a DNA fragment without a centromere can form a new centromere (a neo-centromere). This fragment can survive cell divisions. |
Chorionic Villus Sampling
| What it's not: |
A style of music where musicians insert
snippets of known instrumental or choral songs into their work. . |
What it is:
|
Chorionic villus sampling (CVS) is a
prenatal procedure that examines the chromosomes of fetal cells.
Fetal cells from the fetal side of the placenta (chorionic villi) are
extracted and analyzed for chromosomal and biochemical defects by inserting
a needle through the women’s abdomen or vaginally. The sample
of tissue (chorionic villi) is sent to the laboratory where various
tests can be done. CVS is commonly used to diagnose chromosome conditions
(like Down syndrome) and to diagnose genetic conditions (like cystic
fibrosis) in the pregnancy. It is typically done at around 12 weeks
in the pregnancy. There is about a 1 in 100 risk of miscarriage
associated with the procedure. |
Chromosome
| What it's not: |
An ancient Greek term meaning ‘the colour of his house’. |
| What it is: |
The structure in the cell's nucleus carrying the genes. Each human being has 46 (23 pairs), twenty-three from dad and the other 23 from mom. Males have pairs of chromosomes 1-22 plus an X and a Y chromosome. Females likewise have pairs of chromosomes 1-22 plus two X chromosomes. Each chromosome is one extremely long twisted and folded up strand of DNA. |
Clone
| What it's not: |
to make fun of someone by copying his/her behaviour. “Hey, stop cloning around. You’re hurting her feelings.” |
| What it is: |
An identical copy of an organism. Identical twins have the same nuclear DNA, so they are clones of each other. The same egg and sperm combination has produced two babies during development. Poetically speaking, clones are
Identical in every way,
they are One in DNA.
When gardeners take cuttings from a plant, they are producing clones because the cuttings grow into plants that are genetically identical to the plant they were cut from. See Somatic Cell Nuclear Transfer for a more modern technique. |
Codominant
| What it's not: |
What leaders of the opposition always think they should be. |
| What it is: |
This term refers to different alleles that are both fully expressed and contribute to the phenotype so that neither allele is masked by the other. Common examples are the A and B in human blood types and pink carnations. When both A and B alleles are present on red blood cells, someone has AB blood type, not just A or B. When you cross white and red carnations, you get pink, not one of the original colours. In both these cases, the two different alleles are contributing equally to the final phenotype. |
Codon
| What it's not: |
A Barbarian |
| What it is: |
A codon is three adjacent letters in RNA that “code” for a particular amino acid in protein translation. For only 20 amino acids, there are 64 possible combinations of the RNA bases so several of the codons (letter combinations) code for the same amino acid. As usual, in any subtly efficient system there is more than one way to say the same thing. |
Complementary
| What it's not: |
A free dinner special |
| What it is: |
A property of nucleic acids, whereby adenine (A) always pairs with
thymine (T) while cytosine (C) always pairs with guanine (G). In a DNA
molecule, there are two strands that follow this pairing.
Complementarity is crucial for DNA replication, because one strand can
be used to guide the synthesis of the other strand. The property is
also exploited in Sanger sequencing. |
Congenital
| What it's not: |
Something naughty |
| What it is: |
‘Congenital’ simply refers to a trait in an organism that is present at its birth. The congenital trait can be due to genetic factors, environmental ones or a mixture of them. |
Conserved Genes
| What it's not: |
Genes found in jam and marmalade. |
| What it is: |
These genes are similar across species; that is, conserved through evolution. So they’re likely well-used and necessary for survival. For example, there’s little difference in expression or function of the histone proteins in all organisms from yeast to humans. DNA wraps around histones for proper packaging in the nucleus so mutations that change the histone proteins would be fatal because we need fully functional histones for all aspects of DNA usage (replication, transcription, division, etc.). |
Crossing Over
| What it's not: |
A technique employed by Mediums to connect to your dead relatives
|
| What it is: |
A process that occurs during meiosis. Two members of a chromosome pair twist around one another and exchange genetic information. As are playing cards, genetic material is ‘shuffled’ ensuring that there’s variety in the genetic hand dealt to each organism. It’s how, for example, our grandparent traits are shuffled; we have our maternal grandma’s eyes but grandpa’s hair colour. |
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