Biology: Chapter 11 Assignment

Scientists want to test if amoebas have an allele for a particular gene. They create many copies of a fluorescent probe to inject into the amoebas. Below each amoeba image is the nucleotide sequence of its allele of the target gene. Which amoeba will fluoresce after probe injection? Click on the blue box next to the correct amoeba. Probe sequence: 5' GTACGTGTATGT 3'

(top right) 3' CATGCACATACA 5'

What ethical issues are associated with medical uses of DNA technology? Select all that apply.

- Gene therapy could potentially be used not only for life-threatening illnesses, but also to enhance certain traits. - Genetic tests could be used to screen embryos for desirable traits, such as eye color or sex. - Genetic testing that allows early diagnosis of risk for a disease can potentially cause depression or anxiety in the individual and decrease effectiveness of treatment.

Review the section "Investigating Life: Weeds Get a Boost from Their Transgenic Cousins." What are possible effects of growing transgenic crops that contain a "booster" gene, enabling the crop plants to resist the herbicide glyphosate? Select all that apply.

- Glyphosate will descrease growth of weeds, but transgenic crops will be unharmed. - Transgenic crop plants could spread the "booster" gene to weeds if they cross-pollinate with weedy relatives. - Weeds could also become resistant to glyphosate. - Natural selection could favor the spread of weeds with the booster gene because they have a higher growth rate.

Classify the items as true of specialized cells.

- Number of divisions is limited - Differentiated, in most cases

Why it is useful to be able to rapidly make many copies of a piece of DNA using PCR? Select all that apply.

- PCR is used in preimplantation genetic diagnosis (PGD) and in genetic testing to copy a small sample of DNA until there is enough of it to analyze. - PCR is used to create a genetic profile of a sample taken from a crime scene.

Click on the true statements about DNA. Select all that apply.

- Scientists use DNA sequences to determine guilt in legal cases - Doctors analyze DNA sequences to screen for diseases - The DNA sequence of genes is passed from parents to their offspring - The sequence of mitochondrial genes provides information about human evolution, disease, and inheritance patterns - The sequence of our DNA determines the shape and function of our proteins

Classify the statements below as relating to gene therapy. Some labels might be used more than once. Others might not be used.

- Supplements faulty genes - Uses viruses

Classify the statements below as relating to genetic testing. Some labels might be used more than once. Others might not be used.

- Tests for genetic sequences in developed individuals - Uses DNA probes

Classify the statements below as relating to preimplantation genetic diagnosis (PGD). Some labels might be used more than once. Others might not be used.

- Tests for genetic sequences in embryos - Uses DNA probes

Select all the reasons why STRs are commonly examined in DNA profiling.

- The chances are extremely low that the STR pattern at all loci is identical between two unrelated individuals. - STRs are extremely variable and have many possible alleles at each site.

Classify the items as true of stem cells.

- Undifferentiated - More common early in development than late in development - Totipotent

What are some effects of gene therapy? Select all that apply.

- insert "healthy" genes into cells - silence genes that cause diseases - potentially enhance performance or appearance

Suppose scientists created transgenic crops that express a bacterial protein called Bt toxin. Arrange the following steps for creating a Bt crop in the correct order.

1. Bt gene is extracted from Bacillus 2. Bt gene is inserted into bacterial plasmid 3. Bacterium injects plasmid into plant cells 4. Plasmid becomes incorporated into plant DNA 5. Plant RNA polymerase transcribes Bt gene 6. Plant ribosomes translate mRNA from Bt gene

Match each of the terms associated with DNA technology to their correct descriptions. 1. Electrophoresis 2. Clones 3. Transgenic organisms 4. Gene therapy 5. Somatic cell nuclear transfer 6. Probe

1. Technique used to separate pieces of DNA produced during DNA sequencing 2. Organisms with the exact same DNA as each other 3. Organisms that contain their own DNA and DNA from a different species 4. Technique that uses viruses to deliver "healthy" DNA into cells that have defective genes 5. Technique for producing cloned animals 6. Piece of DNA used to detect complementary pieces of DNA

A DNA restriction enzyme cuts DNA at a specific sequence. If a restriction enzyme that cuts at the DNA sequence GAATTC were used on the DNA strand below, and the resulting fragments were put through electrophoresis, how many bands would appear on the electrophoresis gel?

4

Sequences of a few nucleotides that vary in number of repeats and are used in DNA profiling are called

STRs

What situation best represents how DNA sequencing, PCR, and gene probes might be used together?

Scientists might replicate a strand of DNA using PCR before sequencing it. Once the sequence is known, they can produce a corresponding gene probe.

Place the following genetic elements in order from smallest to largest.

Smallest 1. Adenine 2. Gene 3. Plasmid 4. Chromosome 5. Genome Largest

Review the section "Investigating Life: Weeds Get a Boost from Their Transgenic Cousins." Data from this Investigating Life feature is shown below. If weedy relatives of rice cross-pollinated with transgenic cultivated rice containing a booster gene that helps the crop resist glyphosphate, how did this booster gene affect the growth of weeds if it passed to the weeds?

Transgenic weeds grew faster and became more numerous.