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14 Cards in this Set
- Front
- Back
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The two ways meiosis increases genetic variation areANSWER over and ANSWER assortment.
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Crossing Independent |
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What effect does genetic variation have on modern agriculture?
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Modern agriculture often grow large amounts of plants with little to no genetic variation. While this is ideal for production in good environments, slight changes can wreak havoc on crops because they do not have any individuals with the variations to withstand these changes |
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How is genetic variation decreased?
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Non-random mating
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What does homozygous mean for organisms?
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When an organism has the same allele on both chromosomes, either dominant or recessive. ex) RR or rr
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Explain the difference between phenotype and genotype.
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Genotype refers to the actual allele that an individual has (example: a brown eyed person may be BB or Bb) Phenotype refers to the allele that is displayed in an individual (example: brown eyes)
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Epigenetics describes
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the study of environmental effects on DNA
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What sort of issue does artificial selection present to the diversity and evolution of a population?
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Artificial selection does not allow for genetic variation to occur within a population because it selects for a particular trait to enhance. Without genetic variation, evolution cannot take place because there is no possibility for change in allele frequencies.
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What are the 3 steps during sexual reproduction that lead to genetic diversity through shuffling of alleles?
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During meiosis, alleles get shuffled first through crossing over during prophase I, second independent assortment in anaphase I, and third when chromatids are separated into gametes during anaphase II.
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Which of these traits can undergo genetic variation?
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A. Snail color
B. Flower Color C. Human blood type D. Bacterial sensitivity to antibiotics |
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A _____ exists when phenotypes of a particular organism change along a continuum as a result of geographic and environmental factors.
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cline
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Name and briefly describe laboratory methods for identifying and measuring heterozygous loci in a population.
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The polymerase chain reaction (PCR) technique along with gel electrophoresis may be utilized to amplify and separate DNA fragments. The two methods of PCR that may be utilized to identify heterozygous loci are the amplified fragment length polymorphism (AFLP) method and the restriction fragment length polymorphism (RFLP) method. The AFLP method utilizes different primers for each allele of the gene being measured. At very warm temperatures the DNA strands separate beginning the process of amplification. The temperature is then brought down to allow the primers to anneal to the DNA strand. Extension/replication is done utilizing a special DNA polymerase that is able to withstand very warm temperatures. This process is repeated multiple times, each time doubling the amount of amplified DNA fragments. The fragments are then applied to a gel and electrophoresis is performed. The gel is then stained. If the individual is heterozygous then two bands will form following electrophoresis due to different fragment lengths of the DNA sequences of the measured alleles. If the individual is homozygous there will only be one band. The RFLP method follows a similar procedure; however, the RFLP method utilizes a restriction enzyme (endonuclease) that cleaves the DNA at specific locations based on the nucleotide sequence. This allows another method for the creation of different fragment lengths among the different alleles being measured for the particular gene. Similar amplification techniques (PCR) and electrophoresis procedures follow.
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What are microsatellites and how can they be used? |
short repeating genetic sequences that contain a higher diversity of alleles. Can be used to identify geographic patters in genetic diversity |
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There are two ways that lead to genetic diversity. And explain both. |
Mutation are changes in DNA sequence and it can occur in coding and non-coding regions of DNA, it is caused by mutagens (chemicals, UV light) and also can be caused by errors in DNA replication The second way is Sexual Reproduction which is a reshuffling of alleles between individuals. This happens during meiosis, homologous chromosomes are seperated and recombines to create unique offspring Mutations can occur, leading to copy number variations |
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