3.1 Genes and Chromosomes Flashcards
Define gene
heritable factor, section of DNA that codes for an amino acid sequence of a protein
How do alleles differ from each other
by changes of one or a few bases
New alleles are formed by …
Mutation
Define genome
whole genetic info of an organism
What does the human genome project do
determine entire base sequence of human genes
Cause of sickle cell anemia
base-substitution mutation
Outcomes of the human genome project
identify location of all human genes,
discover protein structures
evidence for human origins
tailor medication to individual genetic variation
Describe the base-substitution mutation of sickle cell anemia
genetic disease
base substitution mutation in the sense strand of hemoglobin gene
different allele of hemoglobin gene
change to base sequence of mRNA
change to amino acid sequence in hemoglobin
Only homozygotes have full sickled cells
Hemoglobin crystallizes at low oxygen conc.
gives resistance to malaria
All members of a species have the same number of…
chromosomes, each with the same genes in the same loci
What technique was used by John Cairns to measure the length of the DNA molecule in Escherichia coli?
Autoradiography
Outline the role of short tandem repeats in DNA profiling
allow individuals to be identified; identify the source of a DNA sample; unique pattern of bands in each individual
State one similarity and one difference between the structure of genes and short tandem repeats (in DNA profiling)
Similarity: both made of DNA; neither has uracil
Difference: genes have longer DNA; genes have introns/exons but tandem repeats do not
Is cystic fibrosis autosomal dominant or recessive? what is the symbol used to express its allele?
autosomal recessive. ff
Is Huntington’s disease autosomal dominant or recessive? what is the symbol used to express its allele?
autosomal dominant. Hh/HH
What is are examples of codominant traits?
Sickle cell amenia (Hb^A Hb^S) blood groups (I^a ii)
