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Biology: Chapter 14 Quiz

Terms in this set (46)

What are two true statements about human genes and chromosomes? (DEFINITELY ON THERE)
1)Chromosomes 22 contains long stretches of repetitive DNA that do not code for proteins
2)Human genes located close together on the same chromosomes tend to be inherited together
What are Sex linked genes?
Genes that are located on the X or Y chromosomes
Is the following sentence true or false? The Y chromosome does not contain any genes at all.
False
Is the following sentence true or false? All X-linked alleles are expressed in males, even if they are recessive.
True
How does the cell adjust to the extra X chromosome in female cells?
In female cells, one X chromosome is switched off
What is Barr Body? (DEFINITELY ON THERE)
A dense region in the nucleus that is formed by the turned off X chromosome
Is the following sentence true or false? Bar bodies are only in males.
False
If you see a white car with orange and black spots, is it most likely male or female?
Female. in cells in some parts of the body, only X chromosome that has the allele for orange spots switched off, where as in cells in other parts of the body, the other X chromosome with the allele for black spots is switched off
What occurs during nondisjunction? (DEFINITELY ON THERE)
Homologous chromosomes fail to separate during meiosis
Is the following sentence true or false? If nondisjunction occurs, gametes may have abnormal number of chromosomes.
True
What is trisomy?
The condition in which an individual has three copies of a chromosome, means "three bodies"
Is the following sentence true or false? Down syndrome occurs when an individual has two copies of chromosome 21.
False
What is a characteristic of down syndrome?
Mental retardation
Why does an extra copy of one chromosome cause so much trouble?
Scientists do not know exactly for sure
What is two things true about sex chromosome disorders?
1) A female with karyotype 45, X has inherited on one X chromosome and is sterile
2) The Y chromosome contains a sex determining region that is necessary for male sexual development
what do biologist use to search the volumes of the human genome?
Sequences of DNA bases
Why might prospective parents decide to have DNA testing?
Genetic tests can determine whether prospective parents risk passing alleles for genetic disorders to their children
What are three things true about genetic testing?
1) labeled DNA probes can be used to detect specific sequences found in disease causing alleles
2) some genetic tests use changes in restriction enzyme cutting site to identify disease causing alleles
3) DNA testing makes it possible to develop more effective therapy and treatment for individual affected by genetic disease
What is DNA fingerprinting?
The identification of individuals by a method that analyzes sections of DNA that have little or no know function but vary widely from one individual to another
What are some sources for a DNA sample from an individual?
Blood, sperm, hair with tissue at the base
What are two true statements about the Human Genome Project?
1) Researches completed the genomes of yeast and fruit flies during the same time they sequences the human genome
2) a working copy of the human genome was completed in June 2000
What were the three major steps in the process of sequencing the human genome?
1) widely separated regions of DNA on each chromosome were sequenced
2) random fragments if DNA were separated
3) computers found overlapping regions between the fragments and positioned them relative to the known markers
What is an open reading frame and what is it used for?
A series of DNA bases that will produce an mRNA sequence, scientists use it to locate genes.
What are the mRNA coding regions of most genes interrupted by?
Introns
List thee other parts of the genes that researched look for.
1) promoter
2) "start" site for transcription
3) "stop" site for transcription
Why are biotechnology companies interested in genetic information?
They are trying to use thin information to develop new drugs and treatments for diseases
Is the following sentence true or false? Human genome data are top secret and can be accessed only by certain people.
False
What is gene therapy? (DEFINITELY ON THERE)
In gene therapy, an absent or faulty gene is replaced by a nirma, working gene
What are two true statements about gene therapy?
1) when the normal copy of gene is inserted, the body can make the correct protein, which eliminates the disorder
2) Viruses are often used ti carry the normal genes in the patients
Is the following sentence true or false? All gene therapy experiments have been successful.
False
Cystic fibrosis (autosomal)
This is autosomal recessive
Sickle Cell Disease (autosomal)
Codominant, bent and twisted shape if the RBC's which results in blood stops moving through the vesseld, damaging cells, tissues organs
Huntington's Disease (autosomal)
Dominant, delayed in life
Dwarfism (autosomal)
Dominant, results in unusual shortness
Downs syndrome (autosomal)
Trisomy 21
Colorblindness (Sex Linked Chromsome)
Recessive allele on X chromosome, inability to distinguish certain colors, especially red and green, mothers can be carriers
Duchenne's Muscular Disorder(sex linked chromsome)
Recessive allele on X chromosome, progressive weakening and loss of skeletal muscle caused by a defective version of the gene that codes for a muscle protein, mostly males get them
Hemophilia (sex linked chromosome)
Recessive allele on X chromosome, blood does not clot normally due to a missing protein required for normal blood clotting, mostly males get them
Turner's Disease (sex linked chromosome
XO (only one X) sex chromosomes, females is sterile, due to nondisjunction of the sex chromosomes
Klinefelter's Disease (Sex linked chromosome)
XXY, XXXY, XXXXY. Males look more feminine.
Why is the Y chromosome important in humans? (DEFINITELY ON THERE)
The Y chromosome has the gene for turning maleness on
What happens to babies born without an X chromosome? (DEFINATELY ON THERE)
They die, you can't live without an X chromosome because too much genetic material is missing
Genotype: HBs HBs, what is it? (DEFINITELY ON THERE)
Sickle cell anemia
Why is DNA fingerprinting important to the criminal justice stystem? (DEFINITELY ON THERE)
They release people that were put in jail without being guilty, they analyze the evidence, they can trace evidence back to one particular individual
Is gene therapy used all the time? (DEFINITELY ON THERE)
No
How are genes delivered to a patient?
By genetically engineered viruses
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