POB Exam 3 Retake

Which is NOT one of the preconditions in a population where natural selection is at work?

All mating in the population is random

In the above pedigree the inheritance pattern is

recessive

The above shows the changes in fossils as ancient land animals evolved into whales. This represents a type of evidence for evolution called

transitional forms

The process of transcription produces _____.

RNA

Disorders involving an unusual number of chromosomes are ultimately caused by:

Nondisjunction

During which stage or stages do sister chromatids separate? More than one may be correct.

Anaphase of meiosis II and Anaphase of mitosis

Which of the classes of RNA molecules carries the genetic information from the nucleus as it is needed for the construction of a protein?

messenger RNA

Consider the images representing steps in elongation of translation above. Which of the following descriptions best corresponds to what is happening at the stage labeled A?

A tRNA with attached amino acid is approaching the ribosome to bind at the A binding site.

The ABO blood group refers to antigens that can be found on red blood cells. Some people have AB blood. This is an example of

codominance

The ______ contain(s) the information for the structure of the protein. There is a hint in the image above.

Exons

Prophase of mitosis and prophase 1 of meiosis are different in that

homologous chromosomes come in contact to allow crossing over in prophase 1 of meiosis but not in prophase of mitosis.

Messenger RNA is produced in the

nucleus

Which of the following are genetically identical?

sister chromatids

Consider the image above. The alleles for the gene for hypercholesterolemia give the above phenotypes depending on the genotypes listed. The pattern of inheritance for this disorder is

incomplete dominance

In which stage of mitosis do the chromosomes line up in the center of the cell?

metaphase

Which of the following would be the transcription of this DNA sequence, ATTCGGAAG, to the complementary mRNA sequence?

UAAGCCUUC

A cell from any eukaryotic species can have its condensed chromosomes removed and stained. A picture of the chromosomes is taken through a microscope and all the homologous pairs can be matched with image software. This can be used to find chromosomal disorders. The image of the chromosomes is called a/an

karyotope

A population of bats lives in a cave. Some of the bats have an allele that gives them pale fur while other bats have brown fur. One evening a storm came up and killed many of the bats while flying. By chance most of the bats carrying the brown fur allele were killed, changing the allele frequency. This is an example of

Genetic Drift

A royal blue painted bunting leaves its group and mates with a green painted bunting in another area. What is this an example of?

Gene Flow

The reason that missing an X chromosome and having an extra X chromosome do NOT cause more harm than they do is best explained by the

inactivation of any X beyond the first as a Barr body.

Match the name of the genetic disorder to it's description. Each answer will be used exactly once.

An autosomal recessive neurodegenerative disorder caused by buildup of lysosomes in nerve cells due to lack of an enzyme.

Tay-Sachs Disease

2

An autosomal recessive disorder in which mucus is abnormally thick, leading to lung infectious. It is caused by a faulty gene for a chloride ion channel protein.

Cystic fibrosis

3

An autosomal recessive disorder in which hemoglobin molecules crystallize into long rods, changing the shape of red blood cells, causing damage to organs and other symptoms. It is caused by a faulty gene for hemoglobin.

Sickle Cell Anemia

4

An autosomal dominant neurodegenerative disorder caused by a faulty gene for a protein. The protein caused other proteins to clump with it damaging nerve cells.

Huntington Disease.

5

An autosomal dominant disorder neurodegenerative disorder caused by a mutation of a gene in nerve cells. The resulting protein is a prion that misfolds and causes other proteins to misfold and clump. This kills nerve cells that allow one to sleep.

Fatal Familial Insomnia

Alternate versions of the same gene are called:

alleles

Traits that are controlled by several sets or pairs of alleles, such as skin color and height in humans, are the result of what form of inheritance?

polygenic

DNA replication, transcription, and the binding of tRNA to the mRNA transcript all work properly in a cell due to

complementary base pairing

Which form of microevolution leads to adaptation?

natural selection

The p53 protein is part of a pathway that inhibits cell division. When the p53 gene mutates it fails to turn on genes that inhibit cell division. The p53 gene is a/an

tumor suppressor gene

The part of a transfer RNA molecule that binds to the codon is the

anticodon

An individual who has an XXY combination of sex chromosomes is said to have _____ syndrome.

Klinefelter

During elongation of translation

the growing polypeptide is transfered to the newly arrived tRNA and amino acid.

The above image shows the 4 basic stages of mitosis, but not necessarily in the proper order. The stage indicated by the letter D is __________.

prophase

Natural selection causes new mutations.

False

Two genes are linked if

they occur on the same chromosome.

Imagine a homozygous individual with type A blood and a heterozygous individual with type B blood have children. Match each blood type with the proportion of children expected to have that blood type. Answers may be used more than once.

A 50%

B 0%

AB 50%

O 0%

Down syndrome is

usually caused by nondisjunction resulting in trisomy of chromosme 21.

Which of the following statements is NOT true about oogenesis, the production of eggs, in humans?

Four equal size daughter cells will form.

If an allele is recessive then

it is not the allele causing the phenotype in a heterozygous individual.

The sex of crocodiles and turtles is determined by the incubation temperature of their eggs. This is an example of the effects that _________________ can have on an organisms phenotype.

the environment

Which type of natural selection increases the frequency of an intermediate phenotype? It is represented by the example of most human babies being born of an intermediate size.

stabilizing

Fertilization in the human life cycle results in

a zygote

The Old Order Amish of Lancaster County, Pennsylvania have a higher rate of polydactyly than the rest of the North American population because one of the original members of that population carried that allele. More than one may be correct.

This is an example of genetic drift

This is an example of the founder effect

One is most likely to find fossils in

sedimentary rock

Anatomical features that are fully developed and functional in one group of organisms but reduced and functionless in a similar group are called

vestigal

Consider the sentence "The dog ate the cat." Which of the following is most like a deletion mutation of DNA.

Tht edo gat eth eca t.

If the diploid chromosome number is 44, the chromosome number of each gamete will be

22

The pigeon is a bird that lives in cities and in the wild in Europe and North America. People capture them and breed them for certain traits, like a certain feather color. All black feathers for example. The genetic differences between pure-bred pigeons and wild pigeons is likely that

wild pigeons are heterozygous for more alleles.

One individual is homozygous dominant for a gene on an autosomal chromosome, another is heterozygous. If they were crossed, what would be the genotypic ratios of their offspring?

1 Homozygous dominant: 1 Heterozygous

A man with straight hair has is homozygous for the straight hair allele and a woman who has curly hair is homozygous for the curly hair allele. Their child has wavy hair. This is an example of

incomplete dominance

Colorblindness is a sex-linked recessive trait. A man has normal vision and a woman is colorblind. If they have a male child, what is the percent chance of it being colorblind? You can find a link to a Punnet square tool in the instructions at the top of the exam.

100%

If a parent cell has a diploid number of 46 chromosomes before mitosis, how many chromosomes will each daughter cell have?

46

Meiosis results in

four haploid cells that are genetically different from one another.

Refer to the genetic code chart above to translate the mRNA sequence AUG-UGU-GUU.

Met-Cys-Val

Fossils (such as Archaeopteryx) of organisms with physical traits that are intermediate between two major groups of organisms are called:

transitional fossils