3/7/23, Genetics Final Study
22:58 Guide
Genetics Final Exam
Important definitions
Base: pyrimidines & purines (C, U, T) (A, G)
Nucleoside: base + sugar (phosphorylated to become a
nucleotide) Nucleotide: phosphate group + sugar + base
Sugar may be ribose (RNA) or deoxyribose (DNA - missing hydroxyl group)
Antiparallel: 2 sequences have opposite orientation with regard to their 5’ & 3’
ends Complementary: AT/GC rule; purines bond to pyrimidines, and vice versa
Intron: Sequence of nucleotides that do not code for proteins (removed during splicing)
Exon: Coding sections of an RNA transcript, or the DNA encoding it, that are translated into protein.
Codon: a sequence of 3 nucleotides
Start codon: AUG
Stop codons: UAG, UAA, UGA
Amino Acid: protein encoded for by specific codons (in 3’s)
Polypeptide: Sequence of amino acids
Gene: a unit of inheritance; a sequence of polypeptides
Open Reading Frame: Nucleotide sequence that can be translated; start codon to stop codon
Allele: Alternate form of a gene at a locus on a chromosome
Genome: complete set of genetic instructions (blueprint)
Central Dogma: DNA replication → RNA → Protein
Semi-Conservative Replication: each DNA molecule composed of ½ of parent & ½ of new complementary
strand
Law of Segregation: alleles randomly separate into two daughter cells
Law of Independent Assortment: the separation of alleles is independent of the separation of other pairs
Inherited: Receive genetic information from predecessors
Congenital: “Born with,” not necessarily heritable, but present at
birth Hot spots: region of the gene more frequently mutated
Loci physical location of a gene on a chromosome
Alleles alternate forms of genes
similar but not identical chromosomes
Homologous Each carries the same genes in the same order, but the alleles
Chromosomes for each trait may not be the same.
about:bl 1/2
,3/7/23, Genetics Final Study
22:58 Guide
Homologous Heterologous
● same structure, value, or
● different structure, value, or position
position
Diploid Haploid
● somatic cells ● gametes
● 2 copies (pair) of homologous ● 1 copy of each chromosome
chromosomes
Phenotype Genotype
● an expressed, observable ● actual sequence of genetic information
trait
Wild Type Mutant
● original (normal) DNA ● alteration in the “normal” DNA sequence
sequence
Dominant Recessive
● allele that is expressed as the phenotype ● allele that is expressed as the phenotype only when it
independent of zygosity is homozygous
Protein Structure
Primary The amino acid sequence
Secondary Folding or coiling from H-bonding
Folding that provides 3D structure
interactions between R groups
Tertiary
Domains
● DNA binding
● Signal molecule binding
Quaternary Assembly of more than one polypeptide chain
RNA Class Name Function
Translated Messenger (mRNA) encodes DNA sequence
transfers an amino acid to
Transfer (tRNA) the polypeptide chain being
assembled during translation
catalyze the assembly of
Transfe amino acids into protein
r chains
Ribosomal (rRNA) bind tRNAs & various
accessory molecules
necessary for protein
synthesis
Heterogeneous nuclear
Minor (hnRNA) Small nuclear
(snRNA)
about:bl 2/2
, 3/7/23, Genetics Final Study
22:58 Guide
Chromosomal Organization Purpose Enzymes Involved
Topoisomerase
further ● Topo II - introduces negative supercoils to help separate
Supercoilin compacts tangled DNA following replication
g chromosome ● Topo I - relaxes negative supercoils; breaks one strand
to relieve tension
Chromosomal Structure Function
Origins of Replication initiate DNA replication
several per chromosome
Centromere chromosome segregation
constricted region in center of chromosome
kinetochore: protein that links centromere to spindle apparatus
Telomere prevents translocations
maintenance of chromosome
ends of chromosome length
tether to nuclear membrane to position chromosome
Structure of Dividing Cells Structure of Nondividing Cells
Euchromatin Heterochromatin
Less condensed regions of Tightly compacted regions of chromosomes
chromosomes Transcriptionally active Transcriptionally inactive
Radial loop domains formed Radial loop domains compacted
Structural Maintenance of Chromosomes Function
Condensin chromosome condensation (short & fat)
Cohesion binding (cohesion) between sister chromatids
Chromosomal Alterations Effect
Deficiencies/Deletions - subtraction loss of a chromosomal segment
Structural: Unbalanced Duplications - addition repetition of a chromosomal
segment
Inversions Breakpoint segment broken
change in direction
Position Effects repositioned
Structural: Balanced
Simple one-way transfer
Translocations Reciprocal two-way transfer
Monosomy missing chromosome
Number
Trisomy extra chromosome
about:bl 3/2
22:58 Guide
Genetics Final Exam
Important definitions
Base: pyrimidines & purines (C, U, T) (A, G)
Nucleoside: base + sugar (phosphorylated to become a
nucleotide) Nucleotide: phosphate group + sugar + base
Sugar may be ribose (RNA) or deoxyribose (DNA - missing hydroxyl group)
Antiparallel: 2 sequences have opposite orientation with regard to their 5’ & 3’
ends Complementary: AT/GC rule; purines bond to pyrimidines, and vice versa
Intron: Sequence of nucleotides that do not code for proteins (removed during splicing)
Exon: Coding sections of an RNA transcript, or the DNA encoding it, that are translated into protein.
Codon: a sequence of 3 nucleotides
Start codon: AUG
Stop codons: UAG, UAA, UGA
Amino Acid: protein encoded for by specific codons (in 3’s)
Polypeptide: Sequence of amino acids
Gene: a unit of inheritance; a sequence of polypeptides
Open Reading Frame: Nucleotide sequence that can be translated; start codon to stop codon
Allele: Alternate form of a gene at a locus on a chromosome
Genome: complete set of genetic instructions (blueprint)
Central Dogma: DNA replication → RNA → Protein
Semi-Conservative Replication: each DNA molecule composed of ½ of parent & ½ of new complementary
strand
Law of Segregation: alleles randomly separate into two daughter cells
Law of Independent Assortment: the separation of alleles is independent of the separation of other pairs
Inherited: Receive genetic information from predecessors
Congenital: “Born with,” not necessarily heritable, but present at
birth Hot spots: region of the gene more frequently mutated
Loci physical location of a gene on a chromosome
Alleles alternate forms of genes
similar but not identical chromosomes
Homologous Each carries the same genes in the same order, but the alleles
Chromosomes for each trait may not be the same.
about:bl 1/2
,3/7/23, Genetics Final Study
22:58 Guide
Homologous Heterologous
● same structure, value, or
● different structure, value, or position
position
Diploid Haploid
● somatic cells ● gametes
● 2 copies (pair) of homologous ● 1 copy of each chromosome
chromosomes
Phenotype Genotype
● an expressed, observable ● actual sequence of genetic information
trait
Wild Type Mutant
● original (normal) DNA ● alteration in the “normal” DNA sequence
sequence
Dominant Recessive
● allele that is expressed as the phenotype ● allele that is expressed as the phenotype only when it
independent of zygosity is homozygous
Protein Structure
Primary The amino acid sequence
Secondary Folding or coiling from H-bonding
Folding that provides 3D structure
interactions between R groups
Tertiary
Domains
● DNA binding
● Signal molecule binding
Quaternary Assembly of more than one polypeptide chain
RNA Class Name Function
Translated Messenger (mRNA) encodes DNA sequence
transfers an amino acid to
Transfer (tRNA) the polypeptide chain being
assembled during translation
catalyze the assembly of
Transfe amino acids into protein
r chains
Ribosomal (rRNA) bind tRNAs & various
accessory molecules
necessary for protein
synthesis
Heterogeneous nuclear
Minor (hnRNA) Small nuclear
(snRNA)
about:bl 2/2
, 3/7/23, Genetics Final Study
22:58 Guide
Chromosomal Organization Purpose Enzymes Involved
Topoisomerase
further ● Topo II - introduces negative supercoils to help separate
Supercoilin compacts tangled DNA following replication
g chromosome ● Topo I - relaxes negative supercoils; breaks one strand
to relieve tension
Chromosomal Structure Function
Origins of Replication initiate DNA replication
several per chromosome
Centromere chromosome segregation
constricted region in center of chromosome
kinetochore: protein that links centromere to spindle apparatus
Telomere prevents translocations
maintenance of chromosome
ends of chromosome length
tether to nuclear membrane to position chromosome
Structure of Dividing Cells Structure of Nondividing Cells
Euchromatin Heterochromatin
Less condensed regions of Tightly compacted regions of chromosomes
chromosomes Transcriptionally active Transcriptionally inactive
Radial loop domains formed Radial loop domains compacted
Structural Maintenance of Chromosomes Function
Condensin chromosome condensation (short & fat)
Cohesion binding (cohesion) between sister chromatids
Chromosomal Alterations Effect
Deficiencies/Deletions - subtraction loss of a chromosomal segment
Structural: Unbalanced Duplications - addition repetition of a chromosomal
segment
Inversions Breakpoint segment broken
change in direction
Position Effects repositioned
Structural: Balanced
Simple one-way transfer
Translocations Reciprocal two-way transfer
Monosomy missing chromosome
Number
Trisomy extra chromosome
about:bl 3/2
