Chapter 14 The Human Genome – Flashcards
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What combination of sex chromosomes produces a human female?
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The combination of two x sex chromosomes are what produce a human female.
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What combination of sex chromosomes produces a human male?
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The combination of one x sex chromosome & one y chromosome are what produce a human male.
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What fact explains why approximately half of the children born are male and half are female?
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The fact that half of the sperm cells that fertilize an egg carry an x chromosome & half carry a y chromosome. Because all eggs carry an x chromosome , half all zygotes will be XX & the other half will be XY.
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In cystic fibrosis, how does a small change in the DNA of a single gene affect a protein?
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Because in cystic fibrosis , the deletion of three bases in the middle of a single gene changes the protein's structure.
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What happens when non-disjunction occurs?
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Chromosomes fail to separate.
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How is DNA fingerprinting commonly used?
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To convict criminals or overturn convictions.
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DNA samples for human DNA can be obtained from....
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a sperm, blood, and hair with attached tissue.
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What type of picture would a biologist look at to determine whether a fetus has Down Syndrome?
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A karyotype because it will show whether or not the fetus has Down Syndrome.
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Why are the X & Y chromosomes called sex chromosomes?
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Because the X & Y chromosomes represent in the embryo determining the sex of the child.
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How many autosomes are found in a human diploid cell?
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There are 44 autosomes that are found in a human diploid cell.
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What type of chart would help a genetic counselor track the passge of a trait through the generations of a family.
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A pedigree chart because it will show a trait that is passed from one generation to the next.
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A picture of chromosomes arranged in pairs are an example of a (an)?
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Karyotype
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The X & Y chromosomes that are involved in sex determination are known as the?
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Autosomes
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The chart below, showing how a trait is passed from one generation to the next family, is called a ( an )?
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Pedigree
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Down Syndrome is caused by what?
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Nondisjunction
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Genes located on the X or Y chromosome are called?
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Sex-Linked
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One example of a sex-linked disorder is ?
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Hemophilia
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Nondisjunction results in a (an)?
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Abnormal number of chromosomes.
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What is the goal of the Human Genome Project?
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To analyze the human DNA sequence.
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what is gene therapy?
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A process of replacing an absent faulty gene with normal, working gene in an attempt to cure a genetic disorder.
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What particles are often used as vehicles to deliver replacement genes to cells in gene therapy?
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Modified Viruses
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How might DNA fingerprinting be used to determine if blood found at a crime scene belonged to the victim or the suspect?
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By DNA samples from the victim & the suspect that would be compared to the DNA in the blood?
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What do you think would be an ethical way for a scientist to manipulate the human DNA? What would be an unethical way? Explain Your answer?
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The most ethical way for scientists to manipulate human DNA would be to change DNA to cure genetic diseases, such as Tay-sachs or cyctic fibrosis. An unethical way to manipulate DNA might be to clone human beings, so that their organs could be harvested for a transplant receipent.
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What is a sex-linked disorder?
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Is one that caused by a defective gene on an X or Y chromosome.
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Under what condition is a single recessive allele expressed in a male?
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When a single recessive allele is expected in a male when it is found on the male x chromosome.
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What common error in meiosis leads to the production of gametes with abnormal numbers of chromosomes?
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Is the production of gametes with abnormal numbers of chromosomes.
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Why would you conclude that the x chromosome is essential for the development of a human embryo, but the Y chromosome is not?
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Because there have been reported instances of babies being born without an x chromosome.
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If you know that a woman has hemophilia, what can you infer about the parent's genotypes?
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Are her mother hemophilia (two recessive alleles) or carries one recessive allele & hemophilia. Her father has the recessive allele for hemophilia.
