Genetics Exam 4

Which statements describe a morphogen?

Acts in a concentration-dependent manner Provides positional information A diffusible molecule

What are the modifications of the Ti plasmid that had to be made to use it as a T-DNA vector.

Addition of restriction sites Removal of genes that cause a gall Addition of selectable marker genes

Which component in the CRISPR-Cas9 system makes a double-strand break in DNA?

Cas9

When a proto-oncogene is converted to an oncogene, which pattern of inheritance is usually observed for the mutated allele?

Dominant

What are the cell layers produced by gastrulation?

Endoderm Mesoderm Ectoderm

cancer cell

a cell that has accumulated genetic changes that allow it to grow uncontrollably

p53

a gene plays a significant role in detecting DNA damage in a cell

In the adult bilateral animal, the left-right axis occurs relative to the ______ axis.

anteroposterior

A bilaterian adult body is organized along two major axes

anteroposterior & dorsoventral

a BT plant contains genes from a

bacterium

The use of living organisms or the materials they produce in the development of goods or processes that are beneficial to humans is called

biotechnology

benign tumor

localized growth with a precancerous genetic change

Heritability is a measurement of the

proportion of phenotypic variance due to genetic variance

An oncogene is formed by mutation that increases the expression of a normal gene called a(n) ______.

proto-oncogene

The natural function of the CRISPR-Cas system in bacteria is to

provide defense against bacteriophages

Tumor-suppressor genes whose normal gene products negatively regulate cell division

rb, p16

The overlapping developmental stages of bilaterians include ______.

segmentation formation of body axes cell differentiation determination of structures within segments

Growth Factor

signaling molecule that can stimulate cells throughout the organism's body to divide

When the CRISPR-Cas system is used for gene mutagenesis, tracrRNA and crRNA are linked together in a molecule called the

single guide RNA

Heritability

the fraction of phenotypic variance that is due to genetic variance

What is the correct order of events in the normal pathway by which growth factors stimulate cell division

1. A growth factor binds to a specific receptor on the surface of a cell 2. A signal transduction pathway activates intracellular proteins to amplify the signal 3. Genes coding for proteins that control cell division are activated

In a normal distribution, what percentage of all individuals have phenotypic values within one standard deviation of the mean

68%

If a population fits a normal distribution, then what percentage of individuals have phenotypic values within two standard deviations above or below the mean?

95%

Normal DIstribution

A frequency distribution in which a trait varies in a symmetrical way around an average value and produces a bell shaped curve

Oncogenes

A mutant gene that is overexpressed and contributes to cancerous growth; promote cancer by increasing transcription of genes that regulate cell division.

What accurately describes the genetic change(s) leading to malignancy?

A series of successive gene changes occurs, involving oncogene activation and inactivation of tumor-suppressor genes

To stimulate the growth of epidermal cells, such as skin cells, which event would occur first?

An epidermal growth factor, EGF, binds to a receptor on the surface of a skin cell.

complex traits

Characteristics that are determined by several genes and are also influenced by environmental factors

Developmental Genetics

Concerned with how genes are involved in the changes that occur during development

What keeps the chains of insulin from being degraded in bacterial cells?

Fusion with β-galactosidase

Four types of genetic changes that can convert a proto-oncogene to an oncogene are

Missense Mutation Gene Amplification Chromosomal Translocation Viral Integration

For the inherited tendency to develop retinoblastoma in the first few years of life, which correctly describes inactivation of the rb tumor-suppressor alleles by the "two-hit" model?

One allele is inactivated prior to birth, the other becomes inactivated early in life.

Which event activates progression through the cell cycle?

Phosphorylation of Rb protein so that it no longer binds to transcription factor E2F.

Which event activates progression through the cell cycle? Multiple choice question.

Phosphorylation of Rb protein so that it no longer binds to transcription factor E2F.

In which two ways have tumor-suppressor genes been shown to act within cells?

Regulating the rate of cell division and maintaining genomic integrity

A cancer-causing mutation in the ras gene leads to an altered Ras protein that ______.

Remains bound to GTP

Which change from proto-oncogene to oncogene occurred by a missense mutation?

Substitution of valine for glycine at position 12 in the amino acid sequence of the rasH protein

What is a quantitative trait locus?

The chromosomal location of one or more genes that affect the phenotype of a quantitative trait

For the non-inherited development of retinoblastoma, which correctly describes inactivation of the rb tumor-suppressor alleles by the "two-hit" model?

The person is born with two active copies of the rb allele; separate mutation events are required to inactivate each of these alleles.

syncytial blastoderm stage

The stage of Drosophila development in which there are many nuclei in the embryo but no individual cells

mutagens

UV light and specific chemicals in cigarettes which promote genetic changes in somatic cells

What is the normal role of Rb protein during the process of cell division?

Unphosphorylated Rb protein prevents progress through the cell cycle by binding to transcription factor E2F.

What is the normal role of Rb protein during the process of cell division? Multiple choice question.

Unphosphorylated Rb protein prevents progress through the cell cycle by binding to transcription factor E2F.

Uncontrolled cell division may result from

a decrease in the expression of tumor suppressor genes

Plant cells that have integrated transgenic T-DNA into their genome should be ______.

able to grow in the presence of carbenicillin and kanamycin

CRISPR-Cas technology has been used to mutate genes in

aldult mice, mice embryos, human cell lines, round worms,plant cells

In the development of retinoblastoma, a retinal cell is more likely to divide if ______. Multiple choice question.

both copies of the rb gene are inactivated

After Cas9 makes a double strand break, which characteristics are observed for repair of the break by homologous recombination repair (HRR)? Multiple select question.

can be used to make a specific point mutation Researcher includes donor DNA that is homologous to the region where the break occurs.

A malignant tumor ______.

can form secondary tumors after spreading to other locations has cells with cancerous mutations leading to uncontrolled growth can invade nearby healthy tissue

Which of the following types of cellular events is involved in the growth of a fertilized egg into an adult organism?

cell differentiation apoptosis cell division cell migration

carcinogen

chemicals in the environment that cause cancer

polygenic

controlled by many genes

quantitative traits are

controlled by multiple genes

When the CRISPR-Cas system is used for gene mutagenesis, which two components are combined in the single guide (sgRNA)?

crRNA & tracrRNA

homeotic gene

essential to determining the identity of a body region

cancer

genetic change that leads to uncontrolled cell growth

invasive cancer cell

grows into the healthy tissue surrounding the tumor

Which of the following categories of proto-oncogenes would encode a product that would be released from one cell and would travel to and affect another cell?

growth factor

Proto-oncogenes that can mutate into oncogenes fall into which of the following categories?

growth factor receptors intracellular signaling proteins growth factors transcription factors

Most individuals who are born with an inherited form of cancer susceptibility are ______ for a defect in a ______.

heterozygous; tumor-suppressor gene

Function of Rb protein

inhibit cell division

In biotechnology, what is used to benefit humans?

living organisms& materials produced by living organisms

Tumor-suppressor genes normally act to ______.

maintain genome integrity negatively regulate cell division

In QTL mapping, researchers try to identify the association between

molecular markers and the phenotypes of quantitative traits

Li-Fraumeni syndrome is an inherited tendency toward cancer development that relates to changes in the tumor-suppressor protein p53. A common change is the substitution of tryptophan for arginine at position 248 in the amino acid sequence. This is an example of inactivating a tumor-suppressor gene through ______.

mutation

The majority of carcinogens promote cancer development by increasing the rate of ______ in somatic cells.

mutation

An oncogene is formed when a proto-oncogene gains a ______

mutation that causes its expression to be abnormally active

A frequency distribution is a graph that shows the

number of individuals in various phenotypic categories

Cancerous growths are clonal in origin because cancer cells ______.

originate from a single cell that has accumulated genetic changes during cell division

Tumor-suppressor genes whose normal gene products help maintain genome integrity are ______.

p53 & BRCA-1

In the CRISPR-Cas system, what part of the sgRNA is designed to be complementary to the gene to be mutated? Multiple choice question.

spacer region

The standard deviation of a data set is equal to the

square root of the variance

When genetic and environmental factors are independent of one another, and genetic variance (VG) and environmental variance (VE) are the only factors that determine phenotypic variance (VP), then VP is equal to the

sum of VG and VE.

Drosophila is used as a model organism to study development because ______.

the larvae are large enough for transplant experiments there are many mutant strains with altered development there are advanced techniques for generating mutants

The p53 protein functions as an activator of

transcription

The region of the p53 protein that corresponds to its main function is the ______ domain.

transcriptional activation

Upon infection of plant cells, Agrobacterium tumefaciens causes ______. Multiple choice question.

tumor growth

malignant growth

type of growth has cells that can invade other tissues and migrate to other areas of the body to form secondary tumors

metastatic

when cancer cells migrate to other parts of the body and cause secondary tumors