Saladin's 02/14/02Ch. 4 TermsPost-copyedit
1)mendelian genetics
2)cytogenetics
3)molecular genetics
4)genomic medicine
5)deoxyribonucleic acid (DNA)
Insight 4.1 Medical History
Miescher and the Discovery of DNA
Swiss biochemist Johann Friedrich Miescher (1844–95) was one of the first scientists intent on identifying the hereditary material in nuclei. In order to isolate nuclei with minimal contamination, Miescher chose to work with cells that have large nuclei and very little cytoplasm. At first he chose white blood cells extracted from the pus in used bandages from a hospital; later, he used the sperm of salmon—probably more agreeable to work with than used bandages! Miescher isolated an acidic substance rich in phosphorus, which he named nuclein. His student, Richard Altmann, later called it nucleic acid—a term we now use for both DNA and RNA. Miescher correctly guessed that “nuclein” (DNA) was the hereditary matter of the cell, but he was unable to provide strong evidence for this conjecture, and his work was harshly criticized. He died of tuberculosis at the age of 51.
6)nucleoli
7)chromatin
8)chromosomes
9)nucleosomes
10)histones
11)nucleotides
12)nitrogenous base
13)cytosine (C)
14)thymine (T)
15)uracil (U)
16)adenine (A)
17)guanine (G)
18)base pairs
19)law of complementary base pairing
20)gene
The essential function of DNA is to serve as a code for the structure of polypeptides synthesized by a cell. A gene is a DNA nucleotide sequence that codes for one polypeptide. The next section of this chapter explains in detail how the genes direct polypeptide synthesis. All the genes of one person are called the genome (JEE-nome); geneticists estimate that a human has about 35,000 genes. These account for only 3% of our DNA; the other 97% does not code for anything. Some of the noncoding DNA serves important organizing roles in the chromatin, and some of it is useless “junk DNA” that has accumulated over the course of human evolution. The latest triumph of molecular genetics is the human genome project, an enormous multinational effort that led to the mapping of the base sequence of the entire human genome. Its completion (in all but some fine details) in June 2000 was hailed as a scientific achievement comparable to putting the first man on the moon.
21)messenger RNA (mRNA)
22)ribosomal RNA (rRNA)
23)transfer RNA (tRNA)
24)genetic code
25)base triplet
26)codon
27)stop codons
28)start codon
29)transcription
30)RNA polymerase
31)translation
32)anticodon
33)polyribosome
34)signal peptide
35)chaperones
36)posttranslational modification
37)transport vesicles
38)Golgi vesicles
39)secretory vesicles
40)DNA helicase
41)DNA polymerase
42)semiconservative replication
43)mutations
44)cell cycle
45)G1 first gap phase
46)S synthesis phase
47)G2 second gap phase
48)M mitotic phase
49)interphase
50)G0 (G-zero) phase
51)mitosis
52)prophase
53)chromatids
54)centromere
55)spindle fibers
56)kinetochore
57)metaphase
58)mitotic spindlewith
59)anaphase
60)telophase
61)cytokinesis
62)growth factors
63)contact inhibition
64)heredity
65)karyotype
66)homologouschromosomes
67)sex chromosomes
68)autosomes
69)germ cells
70)somatic cells
71)diploid
72)haploid
73)genome
74)Human Genome Project (HGP)
75)genomics
76)single-nucleotide polymorphisms
77)genomic medicine
78)locus
79)alleles
80)dominant
81)recessive
82)homozygous
83)heterozygous
84)genotype
85)phenotype
86)carriers
87)multiple alleles
88)gene pool
89)codominant
90)incomplete dominance
91)polygenic (multiple-gene) inheritance
92)pleiotropy
93)sex-linked traits
94)penetrance