E.O.C Exam Study Guide
1. A chromosomal disorder is a chromosome anomaly, abnormality, or aberration is a missing, extra, or irregular portion of chromosomal DNA.
2. Nondisjunction is the failure of chromosome pairs or sister chromatids to separate properly during cell division. An example is Pallister-Killian syndrome.
3. A human cell contains twenty-three pairs of autosomal chromosomes.
4. A human cell contains two sex chromosomes.
5. The components of a DNA molecule consist of two separate strands of DNA running in opposite directions. The three major components in each strand are Deoxyribose, a sugar (notably lacking an oxygen compared to Ribose, which is found in RNA), a phosphate group, and a nucleotide. In the case of DNA, Adenine, Cytosine, Guanine, or Thymine.
6. DNA replication is the process of producing two identical replicas from one original DNA molecule. This biological process occurs in all living organisms and is the basis for biological inheritance.
7. Chargaff's rules state that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine.
8. The components of an RNA molecule are a nitrogenous base, a phosphate group, and ribose sugar.
9. The different RNA molecules are iRNA (interference RNA), RNA interference (RNAi), tmRNA, and Piwi-interacting RNAs.
10. The product of transcription is a strand of messenger RNA.
11. There are several classes of mutations. These include substitution, insertion, deletion, and frameshift.
12. Usually when codons code for the same amino acid, one of the three nucleotide sequences are slightly different. For example, let's say you have AAT and AAC. Without looking at a table of amino acids, you can probably interpret that these two codons code for the same amno acid. But if you have two codons like GGC and AGT, these two are completely unrelated and will not code for the same amino acid.
13. DNA carries the genetic information of a cell and consists of thousands of genes. Each gene serves as a recipe on how to build a protein molecule. Proteins perform important tasks for the cell functions or serve as building blocks. The flow of information from the genes determines the protein composition and thereby the functions of the cell.
14. Selective breeding is simply the process of a breeder developing a cultivated breed over time and then selecting which ones are suitable enough to pass on to the next generation and it has a number of benefits. Some of them are that breeders get to choose which animals fit their criteria; hence more of the right kind of animal can be produced, thus making more products.
15. Inbreeding often causes recessive mutation and diseases of the offspring.
16. The ultimate source of genetic variability is mutation. It is the only way that new alleles and genes are created.
17. The purpose of genetic engineering is to try to re-arrange the genetic structure of living things to create an outcome, either in appearance, behavior or bio-chemical, that we want or need.
18. It is important to know the DNA sequence of an organism because knowing the sequence of an organism's DNA allows researchers to study specific genes.
19. Gel electrophoresis is a process that is used in order to extract DNA. This has also been used to purify the DNA. The DNA is made to polarize in a particular direction.
20. Most transformed cells die because they are too abnormal to function or are abnormal enough for the body's immune system to destroy them. However, if the factors promoting neoplasia persist, a transformed cell may some day give rise to a clone that does continue to grow.
21. What is meant by “survival of the fittest” is that individuals that are best equipped to survive and reproduce perpetuate the highest frequency of genes to descendant populations.