Biology 1050 practice exam questions

If a mutagen reacts with DNA in a cell to form a single DNA adduct, after two cell divisions, how many of the four daughter cells are likely to have the DNA adduct?

1

Mutation that causes Huntington's disease

CAG trinucleotide repeat expansion increases the size of the HTT gene . 36- 100 CAG repeats... protein gets long then cut into small toxic fragments that bind together and accumulate in neurons disrupting the normal functions of these cells

How does smoking cause lung cancer?

Chemicals in tobacco can alter DNA

Any single mutation in a protein coding gene that occurs during DNA replication prior to meiosis in Marisa's Germ line will lead to the production of a defective protein

Disagree- that single mutation could be silent

Which type of cells do you think are most likely to acquired mutations?

Dividing cells

Your friend was recently diagnosed with breast cancer. Your friends breast cancer cells most likely have...

Multiple DNA mutations, with at least one in a protooncogene and one in a tumor suppressor gene

What Is the maximum number of different alleles of p53 you could carry in your body?

2

If a mutagen reacts with DNA in a cell to form a single DNA adduct, after two cell divisions, what percentage of the daughter cells are likely to have the DNA Adduct? After three divisions?

25%....12.5%

What is the probability that the first lamb born to two sheep heterozygous for the black gene will be black ?

42% - 3/4x3/4x3/4 = .75 x .75 x .75 = 42%

How many genes do you think are encoded in the HPV genome?

9 .. (~)-> about

Flower color gene

A gene/ bHLH they are homologs

The HPV E6 gene encodes a protein that binds and inactivates a human protein, contributing to cancer. The function of this human protein is most likely to be..

A transcription factor involved in the transcription of genes that are acquired to be turned on in order for programmed cell death (cell suicide) to occur.

The HPV E6 gene encodes a protein that binds and inactivates a human protein, contributing to cancer. This human protein is most likely to be encoded by..

A tumor suppressor gene

APC gene

A tumor suppressor normally helps keep cell growth in check

Given what you have learned so far, normally functioning p53 most likely recruits RNA polymerase to transcribe genes that are involved in

Apoptosis, Cell cycle arrest

A young woman develops breast cancer; the original mutation responsible for the cancer arose in a single cell. If she and her partner have children after the cancer diagnosis, which of the following is most likely to be true?

None of the woman's children will inherit the mutation

Which of the following are ordered correctly from SMALLEST to LARGEST?

Nucleotide, Exon, gene, X chromosome, human genome

The gene that encodes p53 is a tumor suppressor gene.. mutations that disrupt p53:

Probably promote cell division

Chalcon Synthase (enzyme)

Produces Anthocyanin (purple molecule)

How do promoters and transcription factors work with RNA polymerase to control transcription?

Promoters is a non coding DNA sequence that controls when and where a gene is turned on , the transcription factor is located right above the promoter and are what RNA polymerase bond to

HTT gene

Provides instructions for making a protein called huntington-> exact function unknown.. plays an important part is nerve cells (brain cells)

Promoters

Region of DNA that indicates to an enzyme where to bind to make RNA

What did wexler help do?

developed presymptomatic test to help identify those who carry the fatal gene

Nancy Wexler

discovered the location of the HD gene. (Lake Maracaibo, Venezuela) American geneticist, first psychologist

DNA polymerase

enzyme responsible for forming new copies of DNA in the form of nucleic acid molecules

Gregor Mendel

father of modern genetics

Le gene makes what

ga 20 that converts ga 1 that controls the length of the nodes in the pea plants.

What is the law of segregation and how does it influence the inheritance of traits

when maternal and paternal copies of a gene separate during meiosis when gametes form.

What percentage of cancer-causing mutations do you think are inherited forms ones parents?

~10% are acquired via inheritence ~ 90% are acquired via new mutations

What is the transcription factor for flower do

Required for a specific gene in order to make chalcon synthase (enzyme)

Which of the following is generally true for alleles encoding recessive traits ?

They produce non-functional proteins or no protein at all

Normal CAG?

10-20

Which of the following mutations would you choose for your future child, and why?

Gain of function mutation in a tumor suppressor gene

Which cells contain the genetic information that will be passed on to the woman's children?

Gametes (eggs)

If Herman inherited a predisposition to colon cancer from his father (a mutant allele of the APC gene, for example), which of his cells will carry that mutation?

All cells in his body

If aflatoxin can cause cancer, it probably does this by damaging

DNA

In order for the p53 protein to do it's job as a transcription factor it has to be able to bind

DNA and RNA polymerase

Which of the following kinds of mutations in an exon of a gene will always produce a different protein compared to the protein produced by the normal version of the gene?

Either a single-nucleotide deletion mutation or a single-nucleotide insertion mutation

Which of the following is one way that the process of mitosis and meiosis are different ?

In mitosis there is one cell division step, in meiosis there are two cell division steps.

Genes for stem length

Le gene

If Hermans cancer began with a sporadic (newly acquired) mutation in the APC gene in a cell in his colon, which of his cells will carry that mutation

Mainly his colon cells

A young woman develops breast cancer. The original mutation responsible for the cancer arose in a single cell. What kind of cell is most likely to have acquired the first mutation ?

Somatic cell

Herman has developed colon cancer at a relatively young age (32), the same disease that killed his father. How likely is it that his sister Marisa will also develop colon cancer?

Somewhat likely ~50%

Where do cancer causing mutations come from?

Spontaneous mutations (in the normal course of copying DNA)

Which do you think is least to happen

The chance of inheriting the exact set of chromosomes you inherited from your biological mother and father

What does the A gene and bHLH gene code for

Transcription factors

law of independent assortment

the law that states that genes separate independently of one another in meiosis

p53

tumor suppressor gene that controls cell division and apoptosis .. stops cell growth