Exam 18: Regulation of Gene Expression

Use the following information to answer the questions below. A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. -She tried decreasing the amount of methylation enzymes in the embryonic stem cells and then allowed the cells to further differentiate. Which of the following results would she most likely see?

Which of the following types of RNA are involved in RNAi?

Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts. This is evidence that the product of the bicoid gene

Tumour-suppressor genes

You are given an experimental problem involving control of a gene's expression in the embryo of a particular species. One of your first questions is whether the gene's expression is controlled at the level of transcription or translation. Which of the following might best give you an answer?

In response to chemical signals, prokaryotes can do which of the following?

What defines a proto-oncogene?

Use the following figure to answer the questions below. -What is chemically different between A and B in the above image?

The fact that plants can be cloned from somatic cells demonstrates that

Transcription of the genes in an inducible operon

A lack of which molecule would result in the cell's inability to "turn off" genes?

Use the following information to answer the questions below. A few decades ago, Knudsen and colleagues proposed a theory that, for a normal cell to become a cancer cell, a minimum of two genetic changes had to occur in that cell. Knudsen was studying retinoblastoma, a childhood cancer of the eye. -Knudsen and colleagues also noted that persons with hereditary retinoblastoma that had been treated successfully lived on but then had a higher frequency of developing osteosarcomas (bone cancers)later in life. This provided further evidence of their theory because

Use the following information to answer the questions below. One hereditary disease in humans, called xeroderma pigmentosum (XP), makes homozygous individuals exceptionally susceptible to UV-induced mutation damage in the cells of exposed tissue, especially skin. Without extraordinary avoidance of sunlight exposure, patients soon succumb to numerous skin cancers. -Given the damage caused by UV, the kind of gene affected in those with XP is one whose product is involved with

Allolactose, an isomer of lactose, is formed in small amounts from lactose. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose)as a potential food source. Which of the following occurs when the lactose enters the cell?

Use the following information to answer the questions below. One hereditary disease in humans, called xeroderma pigmentosum (XP), makes homozygous individuals exceptionally susceptible to UV-induced mutation damage in the cells of exposed tissue, especially skin. Without extraordinary avoidance of sunlight exposure, patients soon succumb to numerous skin cancers. -Which of the following best describes this phenomenon?

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called

Drosophila larvae (wt) showing segmentation and anterior-posterior axis. Refer to the image above to answer the following questions. -The product of the gene responsible for anterior-posterior axis is concentrated more in the anterior end. This supports the

Use the following information to answer the questions below. A researcher introduces double-stranded RNA into a culture of mammalian cells, and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe. -In addition, she finds what other evidence of this single-stranded RNA piece's activity?

Use the following figure to answer the questions below. -What does D represent?

Which of the following is an example of post-transcriptional control of gene expression?