BIO 110-Sickle Cell Test Review

Sickle-cell disease is a recessive genetic disease. This means

2 copies of the recessive allele must be present in order for the disease o be expressed.

Meiosis is different from mitosis in that meiosis results in

4 haploid daughter cells that are genetically diverse, whereas mitosis results in 2 diploid daughter cells that are genetically identical

A single mutation causes sickle-cell disease. How does this occur?

A single nucleotide mutation causes a normal glutamic acid amino acid to be replaces with a valine amino acid. This causes the resulting hemoglobin protein to form incorrectly, resulting in sickle-shaped red blood cells that cannot function as intended.

Which events occur in the prophase I phase of meiosis I?

Chromosomes condense, homologous chromosomes form tetrads, crossing over occurs

What is the name of the enzyme that fits new complementary DNA nucleotides to synthesize the new daughter strand?

DNA polymerase

Which traits are considered inheritable?

Eye color

T/F: to transcribe is to make an identical copy; if the original is DNA, the transcribed copy is also DNA.

False

If the codon is CCA, what is the anticodon and what amino acid will be inserted?

GGU, proline

_____ are the basic unit of inheritance that can be passed on from one generation to the next

Genes

Which best describes the definition of a gene?

Genetic info that produces a product, either protein or RNA

Which best describes the structure of a hemoglobin molecule?

Hemoglobin is composed of 4 globin molecules, each with their own heme group that binds to and carries oxygen.

Which event occurs in the anaphase I phase of meiosis I

Homologous chromosomes are pulled apart to opposite poles

_____ contain similar genes but often different alleles. After DNA replication, _____ contain identical alleles combinations.

Homologous chromosomes; sister chromatids

What statement best describes how a mutation changes the shape of a protein?

If a mutation occurs during DNA replication, the affected gene may produce a protein that is misfolded

Which best describes the characteristics of a genetic disease?

It is a change in genetic info that may be passed on from one generation to the next

What is the role of the enzyme ligase in DNA replication?

Links the gaps between Okasaki fragments in the lagging strand

Which is an example of a phenotype influenced by the environment?

Melanin production

Which events occur in the telophase II phase of meiosis II?

Nuclear membrane begins to form, and a cleavage furrow begins to develop

Describe the movement of oxygen and carbon dioxide during gas exchange.

Oxygen diffuses out of the lungs into red blood cells and carbon dioxide diffuses out of red blood cells and into the lungs

The F1 generation results from the fertilization of ______

P gametes

Sickle-cell disease results in malformed hemoglobin molecules. Which cell type contains millions of hemoglobin molecules per cell?

Red blood cells

Which event occurs in the anaphase II phase of meiosis II?

Sister chromatids are pulled apart to opposite poles

Which best describes how the environment may play a role in the expression of our genes?

Some phenotypes can be influenced by the environment. The genotype still determines some aspect of skin color, but the interaction with the environment, in the form of sun exposure, can cause variations in the resulting phenotype.

Which event occurs in the metaphase I phase of meiosis I?

Tetrads align along the metaphase plate

What is the function of the respiratory system within the body?

The exchange of oxygen + carbon dioxide with the external environment.

Which best explains the role of transcription in a cell?

To produce a mRNA molecule to deliver the genetic instructions outside the nucleus.

Which plays the role of interpreting the genetic info from the mRNA into a structural protein that is used by the cell?

Translation

Two parents, one with Type A blood and one with Type B blood have a child with type AB blood. How is this possible?

Type A blood is codominant with Type B blood, so both alleles are expressed equally

The overall goal of gene expression is to make

a structural protein that can be used by the cell.

The purpose of ______ is to pass a copy of a cell's gene to cells in the next generation. The purpose of _____ is to pass the parents' genes onto the next generation.

cell division; sexual reproduction

Red blood cells are responsible for

gas exchange throughout the body

Crossing-over produces genetic variation during prophase I of meiosis I. This occurs when

homologous chromosomes come close together and a rearrangement of alleles occurs.

If a person shows an intermediate phenotype, such as that observed in a person who us heterozygous for familial hypercholesterolemia, this indicates the pattern of inheritance to be

incomplete dominance

There are 2 main forms of non-Mendelian inheritance. In _____, as observed in familial hypercholesterolemia, the dominant allele does not completely mask the recessive allele. In _____, as observed in the AB blood type, 2 dominant alleles are fully expressed for the same trait.

incomplete dominance; codominance

The oxygen exchange between the red blood cells and the alveoli is driven by diffusion. This diffusion is due to the

lower amount of oxygen found in the red blood cells

In the human life cycle, gametes are formed through the process of _____, and all other cells are formed through the process of _____

meiosis; mitosis

The hemoglobin molecule is a

protein

In gene expression, the goal of translation is to

read codons and incorporate corresponding amino acids into a growing peptide chain

For the expression of a recessive trait, a person needs to inherit a

recessive allele from both of their parents

DNA strands are complementary of each other. This means if one strand has an adenine the other has a ______, and of one strand has a guanine the other has a _____

thymine; cytosine

Sickle-cell disease is a disorder that results in malformed hemoglobin molecules. What is the result in this in terms of hemoglobin function?

Hemoglobin has a reduced ability to bind to and transport oxygen in red blood cells.

Which event occurs in the metaphase II phase of meiosis II?

Sister chromatids align along the metaphase plate

DNA replication is considered to be _____ because the end product consists of one old strand and one newly synthesized strand.

semiconservative

During translation, a polypeptide chain is created using an RNA template. Which is responsible for bringing amino acids to the growing polypeptide chain?

tRNA