Download BSC 1010 Exam 3 Study Guide

BSC 1010 Exam 3 Study Guide
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Chapter 12: Patterns of Inheritance
1. Early ideas of heredity
• Mendelʼs Experiments disproved the theory of blending
2. Monohybrid cross:
• a cross to study only 2 variations of a single trait
3. Dihybrid cross
• a cross to study 2 variations of two traits
3. Define/ Describe:
a. Genotype:
b. Phenotype:
c. Dominant trait:
d. Recessive trait:
e. Gene:
f. Allele:
g. Homozygous:
h. Heterozygous:
i. Carrier:
• Genotype of a carrier:
• Phenotype of a carrier:
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BSC 1010 Exam 3 Study Guide
4. Principle of segregation:
• what does it state?
• how does it account for genetic variation?
5. Principle of independant assortment:
• what does it state?
• how does it account for genetic variation?
6. Test Cross
• why is a test cross performed?
• be prepared to use a test cross to determine if parent organism is homozygous
dominant or heterozygous:
7. Extensions to Mendel: Other Types of Inheritance:
• Define/ Describe:
a. Polygenic Inheritance:
• show continuous variation referred to as quantitative traits:
b. Pleiotropy:
c. Incomplete dominance:
d. Codominance:
• Human blood typing
• genotypes and phenotypes for blood types
• be prepared to determine blood type using Punnett square
e. Environmental influences can affect gene expression (Epigenetics)
f. Epistasis:
• Be prepared to determine genotypic and phenotypic ratios using Punnett
squares, see practice template attached.
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BSC 1010 Exam 3 Study Guide
Chapter 13: Chromosomes, Mapping, and the Meiosis-Inheritance Connection
1. Chromosomal Theory of Inheritance:
• proposed that genes are present on chromosomes
• based on observations that homologous chromosomes pair with each other
during meiosis and that particular traits could be associated with X chromosome
of fruit flies.
2. Sex Chromosomes
• Sex chromosomes vs. autosomes
• Sex determination in humans:
• Male chromosomes:
• Female chromosomes:
• Define/ Describe:
a. Sex-linked trait:
b. Autosome:
• How do the patterns of expression of sex-linked traits differ from those of genes
on autosomes:
• X-linked traits seen more commonly in which gender, why?
• Dosage Compensation:
• ensures equal expression of genes on sex chromosomes in both sexes
• Barr body:
• Genetic mosaic:
• phenotype depends on which X chromosome inactivated
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BSC 1010 Exam 3 Study Guide
3. Chromosome Theory Exceptions
• Mitochondria and Chloroplasts have their own genomes
• traits controlled by these genes do not follow the chromosomal theory of
inheritance
• Maternal inheritance:
4. Genetic Mapping
• The science of determining the location of a gene on a chromosome
• Based on the recombination frequency of genes
5. Human Genetic Disorders
• Faulty genes code for faulty primary structure of proteins
• Sickle cell anemia:
• protein affected?
• how is the protein changed by the mutation?
• how does this affect protein structure and function to cause disease?
• Nondisjunction:
• define/ describe:
• how/ when does it occur?
• monosomy:
• trisomy:
• provide an example of a trisomy genetic disorder:
6. Genetic Imprinting
• occurs when the phenotype exhibited by a particular allele depends on which
parent contributed the allele to the offspring
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BSC 1010 Exam 3 Study Guide
Chapter 15: Genes
1. The Nature of Genes
• Genes code for proteins
• What does it mean to ʻexpressʼ a gene?
• Connection was made by linking a disease as result of a nonfunctioning
enzyme to an altered gene
• One Gene - One Protein Hypothesis:
• The Central Dogma of Molecular Biology: Describes the flow in information from
genes to protein
• Replication:
• DNA to DNA
• Where in cell:
• When during cell cycle:
• How (what enzymes, structures are involved):
• DNA polymerases
• Mutations:
• Briefly describe each step:
1. Initiation:
2. Elongation:
3. Termination:
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BSC 1010 Exam 3 Study Guide
• Transcription:
• DNA to RNA
• type of RNA produced:
• Where in cell:
• When during cell cycle:
• How (what enzymes, structures are involved):
• DNA coding strand vs. template strand
• RNA polymerases
• Transcriptional Unit (on the DNA)
1. Promoter
2. Coding region
3. Terminator sequence
• Post-Transcriptional modifications of mRNA transcript
• introns vs. exons
• Briefly describe each step:
• Initiation:
• Elongation:
• Termination:
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BSC 1010 Exam 3 Study Guide
• Translation:
• RNA to Protein
• Where in cell:
• When during cell cycle:
• How (what enzymes, structures are involved):
• Ribosome
• mRNA
• codon
• tRNA
• anticodon
• Wobble pairing
• Briefly describe each step:
1. Initiation:
2. Elongation:
3. Termination:
• The Genetic Code
• The code is degenerate:
• there are 64 codes for 22 amino acids
• how is this protective against mutations?
• The code is universal:
• There are start codons:
• Why do many proteins begin with the amino acid
methionine?
• There are stop codons:
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BSC 1010 Exam 3 Study Guide
• Mutations
4. Point Mutations:
• Base-Substitutions:
a. Missense mutations:
b. Nonsense mutations:
c. Frameshift mutations:
• insertions or deletions
d. Silent mutations:
• Which of the point mutations will most likely have the most
deleterious effects on the cell and why?
5. Triplet Repeat Expansion Mutations:
6. Chromosomal Mutations:
• Change the structure of the chromosome and affect
multiple genes
a. Deletions:
b. Duplications:
c. Inversions:
d. Translocations:
• How do chromosomal mutations differ from point
mutations?
• How do chromosomal mutations differ from chromosomal
aberrations like those observed with Down Syndrome and
Turner Syndrome?
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