Exam3 biol 230

A couple has one child. Three years later they are expecting another child. Assuming that there are no new mutations and that there is no meiotic crossover, what are the chances that the second child will be genetically identical to the first child?

(1/2)^46

Part I: Compare and contrast the purposes of MITOSIS and MEIOSIS. Include in your response what kinds of cells undergo each process and how many cells are produced

+ 0.5 point each for the following • MITOSIS ocurs in somatic cells, in particular stem cells that are unspecialized and retain the ability to divide. • MEIOSIS occurs in germline cells that are dividing to produce gametes or sex cells, such as sperm cells or egg cells. + 0.5 point each for the following • MITOSIS produces TWO cells that are diploid and copies of the original cell. • MEIOSIS produces FOUR cells that are haploid and that differ genetically from one another.

A young man (32) with colon cancer was found to have sporadic mutation in the APC gene in his colon cells. What are the chances he will pass this mutated allele on to his child?

0%

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

1

Which of the following cells are most likely to acquire mutations?

Cells undergoing DNA replication

Remember what you have learned about mitosis and meiosis. Which of the following statements are scientifically accurate?

During Meiosis I (first cell division), homologous chromosomes separate and end up in two different cells.

There is a gene located on chromosome 17 in humans for which four different alleles have been identified. The maximum number of alleles a single normal individual can have is:

2

Sickle cell anemia in humans is caused by mutations in a single gene and is inherited as an autosomal (non-sex chromosome) recessive trait. A normal couple has one child who has sickle cell anemia. The couple is contemplating a second child. What is the probability that the second child will not have sickle cell anemia?

3/4

If 15% of the DNA in a chromosome is made of Guanine, what percentage of the chromosome is made of Adenine?

35%

If a mutagen such as aflatoxin reacts with DNA in a cell to form a single DNA adduct, after four cell divisions, how many of the cells will have a mutation?

8

Which of the following is scientifically accurate?

Mutations can be beneficial to organisms. Mutations arise due to changes in nucleic acid sequences.

A young woman develops breast cancer that does not spread to any other tissues; the original mutation responsible for the cancer arose in a single breast cell. If she and her husband (who does not have cancer) have children after the breast cancer diagnosis, which of the following statements is most likely to be true?

None of the woman's children will inherit the mutation.

Which of the following statements best represents the current understanding of prions?

Prions are proteins that are infectious when mis-folded.

Remember what you have learned about the four major classes of biological macromolecules. Which of the following statements are scientifically accurate?

RNA polymerase is a protein.

Which of the following statements about getting from a GENE to a TRAIT is most biologically accurate?

RNA polymerase produces RNA molecules during transcription.

Which of the following statements about getting from a GENE to a TRAIT is most biologically accurate?

RNA polymerase produces RNA molecules during transcription.

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

If the silk protein gene from a spider is attached to a mammary gland promoter and inserted into the first cell of a goat embryo, which of the following statements is correct?

The silk protein will be produced only in the mammary cells in the adult goat.

What are telomeres?

They are made of non-coding DNA.

Which of the following is generally true for recessive alleles?

They produce non-functional proteins or no protein at all.

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

nucleotide, codon, intron, gene, genome

Which type of cancer-causing mutation is most likely to be dominant?

Gain-of-function mutation in a proto-oncogene

You are trying to create a genetically engineered dairy cow that will be less likely to get cancer. Which of the following alterations to the cow's genome is most likely to accomplish this task?

Gain-of-function mutation in a tumor suppressor gene

Which of the following human cells contains the gene that codes for hemoglobin, the protein that transports oxygen in the blood?

Gametes, cells in the blood, and cells in the brain

Which of the following human cells contain the genes that code for P53?

Gametes, cells in the colon, and cells in the skin

In the fish below, horizontal and vertical stripes are controlled by the same gene. If the HORIZONTAL stripes are encoded by a recessive allele (h) and the VERTICAL stripes are encoded by a dominant allele (H), what is the genotype of the parent fish with the VERTICAL stripes?

HH or Hh

The bonds that hold together two DNA molecules that make up a double helix are...

weak hydrogen bonds

A slot machine has 10 slots. Each slot has 4 different fruits on the spinner (apple, pear, grape, and cherry). What are the odds of getting a cherry in BOTH the first AND the second slots?

1/16

You have 23 pairs of chromosomes in your somatic cells. Each homologous pair is comprised of one chromosome from your mother and one from your father. What are the chances of making a gamete (sperm cell or egg cell) in which all of the chromosomes are from your father? For this question, assume that there is no meiotic crossing-over.

1/2 ^23

"During mitosis, DNA is copied once to produce two diploid cells. During meiosis, DNA is copied once to produce four haploid cells." AGREE (+1 point) DISAGREE

AGREE (+1 point) + 1 point each, up to 2 points total, for the following or other scientifically accurate and relevant arguments .. • During MITOSIS, DNA is copied only ONCE. • During MITOSIS, TWO diploid cells are produced. • During MEIOSIS, FOUR haploid cells are produced. • During MEIOSIS, DNA is indeed copied only ONCE

Template DNA Sequence: 3'TAC GAA TCC TAA GTG ACG...S° 23. Which of the following do you predict is the mRNA sequence that this template DNA sequence codes for?

AUG CUU AGG AUU CAC UGC.

«The vast majority of cells in your body are able to divide» AGREE DISAGREE

DISAGREE (+1 point) + 1 point each, up to 2 points total, for the following or other scientifically accurate and relevant arguments . • the vast majority of your cells - skin cells, nerve cells, colon cells, etc. - are highly specialized cells and can no longer undergo mitosis (cell division) • there are stem cells in each tissue that retain the ability to undergo mitosis (cell division) • when stem cells divide, they produce one cell that will remain an unspecialized stem cell and another cell that will become specialized (e.g., become a skin cell).

Then, provide AT LEAST TWO ARGUMENTS using the language of biology as to why the statement is scientifically accurate or not. "DNA turns unto RNA, and then RNA polymerase builds protein." AGREE DISAGREE

DISAGREE (+1 points) + 1 point each, up to 2 points total, for the following or other scientifically accurate and relevant arguments ... • DNA is unchanged in the process of transcription to build a new RNA molecule. • DNA codes for RNA, does not turn into RNA • Some of the sequences of nucleotides in DNA (only about 1.5%) are genes that code for the building of a specific, new RNA molecule. • RNA polymerase is an enzyme that is used to transcribe RNA, does not build proteins.

Which of the following is the most scientifically accurate statement about DNA replication compared to transcription/translation (central dogma)?

DNA replication occurs in some cells, while transcription/translation occurs in virtually all cells.

1. Biologists at the California Academy have discovered a new life form and collected a sample specimen that appears to have a cell membrane, a chloroplast, and ribosomes. This specimen could be...

Eukaryote

Which of the following types of sequences in a chromosome directly code for a protein?

Exons

Which of the following DNA sequences would require the most energy to separate the two strands?

GCCCGCCGCCCCTAG CGGGCGGCGGGGATC

Where does RNA splicing occur in the Eukaryotic cell?

In the nucleus

Template DNA Sequence: 3'TAC GAA TCC TAA GTG ACG...S° Which of the following do you predict is the protein sequence that this template DNA sequence codes for?

MET LEU ARG ILE HIS CYS.

Suppose that you have two sheep of opposite sex. Both are homozygous. One has a black coat, and the other has a white coat, but you don't know which is the recessive trait. Which of the following investigations would reveal the dominant coat color?

Mate them together and see what coat color the offspring have - that will be the dominant coat color.

Which of the following pieces of evidence supports the Endosymbiotic Theory of the origins of eukaryotes?

Mitochondria contain ribosomes and DNA similar to prokaryotes.

Which of the following statements is CORRECT about Henrietta Lacks or her cancerous cells?

She was African-American.

If a single point mutation occurs at a random place in the genome, what is the most likely outcome?

The mutation will have no noticeable effect on the organism

Remember what you have learned about the four major classes of biological macromolecules. Which of the following statements are scientifically accurate?

The p53 transcription factor is made up of amino acids.

If a mutation was made so that the 6th codon in the Template DNA sequence became ACA. how would that change the protein that is produced?

The protein produced would be exactly the same.

A current UC Santa Cruz graduate student who earned their biology degree at SFSU is doing research to replicate classic experiments that investigated the inheritance patterns of traits in the sweet pea plant. In one experiment, they mated a plant with wrinkled seeds (plant A) to a plant with smooth seeds (plant B). Of the resulting 100 offspring plants, they noted that 48 had wrinkled seeds and 52 had smooth seeds. Answer the questions below and make sure you fully explain your logic. Based on the results of the experiment above, can you conclude that the wrinkled phenotype is recessive to the smooth phenotype? Why or why not?

[3 points: 1 for responding NO, 2 for the explanation] No, it is not possible. One is heterozygous and the other is homozygous recessive to get half smooth and half wrinkled, but you can't tell which is which.

A current UC Santa Cruz graduate student who earned their biology degree at SFSU is doing research to replicate classic experiments that investigated the inheritance patterns of traits in the sweet pea plant. In one experiment, they mated a plant with wrinkled seeds (plant A) to a plant with smooth seeds (plant B). Of the resulting 100 offspring plants, they noted that 48 had wrinkled seeds and 52 had smooth seeds. Answer the questions below and make sure you fully explain your logic. In a subsequent experiment, they crossed two of the smooth pea plants that resulted from the original cross. Of the 100 offspring, 24 plants had wrinkled seeds and 76 had smooth seeds. Can you conclude from this which of the two phenotypes is dominant? Explain your reasoning.

[3 points: 1 for stating SMOOTH must be dominant, 2 for the explanation) If smooth is recessive, then all the offspring of a smooth X smooth cross would be smooth. There could be no wrinkled allele present. If smooth is dominant, then crossing two smooth heterozygotes (smooth/wrinkled) would give ¾ smooth pea plants (either smooth/smooth or smooth/wrinkled) and ¼ wrinkled pea plants (wrinkled/wrinkled).

A current UC Santa Cruz graduate student who earned their biology degree at SFSU is doing research to replicate classic experiments that investigated the inheritance patterns of traits in the sweet pea plant. In one experiment, they mated a plant with wrinkled seeds (plant A) to a plant with smooth seeds (plant B). Of the resulting 100 offspring plants, they noted that 48 had wrinkled seeds and 52 had smooth seeds. Answer the questions below and make sure you fully explain your logic. Based on the results of both crosses, what were the genotypes of the original two plants (plant A and plant B)? How did you figure this out?

[3 points: 2 for giving the phenotypes, 1 for the explanation] We know from Part 2 that smooth is dominant. So Plant B must be homozygous recessive (wrinkled/wrinkled) and plant A must be heterozygous (smooth/wrinkled). That's the only way to get half of the offspring of the first cross to be smooth (smooth/wrinkled) and half to be wrinkled (wrinkled/wrinkled).

The types of mutations that are hypothesized to underlie many types of cancer are...

loss-of-function mutations in tumor suppressor genes

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

mitochondrion, virus, hemoglobin, glucose, water molecule

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

mitochondrion, virus, prion, glucose, water molecule

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

nucleotide, codon, gene, X chromosome, human genome

Pea plants can have purple flowers (dominant, *A") or white flowers (recessive, 'a'). If a pea plant has white flowers, its genotype can be ..

only aa

Which of these is a tumor suppressor gene?

p53

Different cells in the human body are able to do different functions primarily because they have different..

proteins

The genetic information in DNA molecules is stored in the...

sequence of nitrogenous bases

Part II: In the space below, sketch MITOSIS and MEIOSIS for ONE PAIR of HOMOLOGOUS CHROMOSOMES (5 points) chromosome from a female parent is marked with chromosome from the male parent is marked with Please label where DNA Duplication and CELL DIVISION(s) happen in your sketches. MITOSIS MEIOSIS

starting cell>>>> starting cell>>>> m 1 + 1 point each for the following... + 1 point each for the following... • starting cell drawn with one pair of homologous • starting cell drawn with one pair of homologous chromosomes, as above chromosomes, as above • DNA DUPLICATION within a single cell where • DNA DUPLICATION within a single cell where M is M is now two sister chromatids (labeled M now two sister chromatids (labeled M and M, and M, connected by a centromere), and F connected by a centromere), and F has two sister has two sister chromatids (labeled F and F, chromatids (labeled F and F, connected by a connected by a centromere) centromere) CELL DIVISION produces TWO ending cells that appear as copies of the original cell, which is a diploid cell • FIRST CELL DIVISION produces TWO cells, ONE with only the duplicated M chromosome, and the OTHER with only the duplicated F chromosome • SECOND CELL DIVISION produces FOUR ending cells that are haploid: one cell has an M chromosome, another cell has an M chromosome, one cell has an F chromosome, another cell has an F chromos OHIO