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37 Cards in this Set
- Front
- Back
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A catholic monk, _____ ______, learns about nature through the experimental method and a mathematical model he develops well ahead of his time
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Gregor Mendel
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What organism did Mendel experiment on?
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Garden pea
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How do you cross pollinate?
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cut anthers off one plant, while immature. Take mature pollen from other plant and fertilize the first
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When Mendel crossed green/yellow peas, what did the offspring look like?
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yellow parent (yellow was the dominant trait)
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How did he explain this result?
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each parent had 2 alleles, each one gave an allele to the offspring
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What is an allele?
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"matched pairs", alternative forms of a gene
versions of a gene on a chromosome |
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What is the order of dominance for genes?
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YY&Yy are greater than yy
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Describe the F1 generation when Mendel let them self fertilize
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Yy, Yy, Yy, Yy
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Describe the F2 generation
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YY, Yy, Yy, yy
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What are the genotypes/phenotypes?
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genotypes=YY, Yy, yy
phenotypes=yellow, green |
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What is the rule of multiplication?
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probability of getting a girl the first time AND a boy the second time?
.5x.5=.25 |
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What is the rule of addition?
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probability of getting a boy the first time OR a girl the first time?
.5+.5=1 |
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What is a dihybrid cross?
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plants differ in 2 characteristics
Fig 11.9--> smooth yellow and wrinkled green |
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What is the 9:3:3:1 ratio?
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by phenotype:
9-smooth yellow 3-wrinkled yellow 3-smooth yellow 1-wrinkled green |
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What are Mendel's four postulates?
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1. every gene has two alleles
2. one allele is dominant over other 3. law of segregation (an offspring has = chance of getting either of the parents 2 alleles) 4. law of independent assortment (mom/dad genes dont affect eachother or affect which one is picked for offspring) |
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What is X-linked inheritance?
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x linked inheritance is the mutation in genes on the x chromosome. they have unique inheritance patterns
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How is red green colorblindness inherited?
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red green colorblindness is inherited on the x chromosome as a recessive order, and wont be present in the presence of a functional allele (why its more common in males (xy))
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Why is an x linked trait sometimes said to skip a generation?
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because it is recessive/not always apparent. "carriers"--> heterozygous (Ss)
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If two parents are heterozygoues for the sickle cell trait, what is the probability that their next offspring will have sickle cell anemia?
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offspring has 1/4 chance of getting it (SS, Ss, Ss, ss)
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Huntington's disease is a _______ disorder
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dominant
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What is a pedigree?
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a familial history intended to track genetic conditions
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What are the symbols for female, male, carrier and affected?
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female=circle
male-square carrier=half shaded affected=shaded in |
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What is nondisjunction?
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failure of homolugs chromosomes or sister chromatids to separate during meiosis
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What is the main cause of down syndrome?
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3 copies of chromosome 21
likelihood of child with down increases with a mothers age |
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What causes cri-du-chat syndrome?
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partial deletion of chromosome 5
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What is deletion?
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chromosome fragment breaks off n then does not rejoin any chromosome
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What is inversion?
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a chromosomal abnormality when a chromosome fragment rejoins a chromosome with an inverted orientation
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What is translocation?
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2 not homologus chromosomes exchange pieces (changes phenotype)
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What is duplication?
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"crossing over" -->exchange unqeual pieces, and eventually duplicates a piece more than once
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What is xray diffraction?
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purified molecule is bombarded with xrays, scattering of xrays after it hits the molecule tells something about it's structure
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What are the 3 chemical groups that make up DNA?
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base, sugar, phosphate
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DNA is a double helix staircase: with _____-_________ rails and ____-_______ stairs
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sugar-phosphate rails and base-pairing stairs
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True or false: 2 strands are complementary and parallel
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FALSE: complementary and anti-parallel
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What are the basic steps of DNA replication?
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1. DNA to be replicated
2. strands separate 3. each strand is a template for synthesis of a separate DNA molecule. Free nucleotides base pair with nucleotides on existing strands (A&T, C&G) 4. 2 identical strands of DNA |
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What is a point mutation?
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mutation of a single base pair in the genome
G&T are accidentally paired up, so they are pushed out and replaced with a correct base pair of A&T |
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What is spontaneous mutation?
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not avoidable, mistakes in DNA synthesis
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What is induced mutations?
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radiation: UV, Xrays, radon
chemical mutogens: mustard gas, nitrous acid from nitrates in some food, etc |
