chapter 15 genetics

Arrange the following in the proper order in which they occur during glucocorticoid hormone action. 1. Binding of hormone to receptor 2. Release of HSP90 proteins 3. Entry of hormone into the nucleus 2, 3, 1 3, 2, 1 2, 1, 3 1, 2, 3 3, 1, 2

1 2 3

Covalent modifications occur due to protein activation by the addition of what functional group Addition of a phosphate (-PO4) group Addition of a carboxyl group (-COOH) group Addition of a methyl (-CH3) group Addition of a hydroxyl (-OH) group

Addition of a phosphate (-PO4) group ```

Glucocorticoid receptors are membrane bound t/f

F

Glucocorticoid receptors bind to GRE elements which are present on newly synthesized mRNAs t/f

F

Estrogen is a gonadocorticoid t/f

T

Glucocorticoid receptors have a nuclear localization signal that is hidden until a glucocorticoid is bound t/f

T

Glucocorticoid response elements function as enhancers. true or false

T

The glucocorticoid receptor is active as a dimer true or false

T

Two glucocorticoid receptors function as a homodimer t/f

T

Which of the following is true with regards to enhancer sequences They may be located either upstream or downstream of the promoter. They cannot be downstream of the start of transcription. They are orientation-dependent. Repressor proteins bind to them.

They may be located either upstream or downstream of the promoter.

Most extracellular signaling molecules can enter cells directly t/f

f

Steroid hormones are synthesized in the same cells where they function true or false

f

DNA methylation in eukaryotes, which is associated with transcription inhibition, occurs on A residues at GATC sites. true false

false

Eukaryotic cells are less likely to respond to their environment than prokaryotic cells true or false

false

Genes may be regulated in eukaryotes by modifications to the core of histone proteins\ true or false

false

Maintenance methylation of DNA is rare and highly regulated true or false

false

Regulatory transcription factors called repressors bind to a sequence in the DNA called a silencer and serve to enhance the rate of transcription true or false

false

Typically, in eukaryotes, regulatory transcription factors recognize the trans-acting elements located near the core promoter region true or false

false

X-inactivation is not necessary in females since they need to express two (2) X chromosomes in order to have female characteristics t/f

false

Generally, transcriptional regulators recognize short, but specific cis-regulatory sequences in the ______________ groove of DNA

major

Cis-regulatory sequences are found on the ___________________ chromosome as the gene they control

same

DNA methylation, while inheritable, can inhibit transcription t/f

t

Patterns of transcriptional regulation can be inherited from mother to offspring through DNA methylation t/f

t

Regulatory transcription factors may exert their effects through TFIID and Mediator complexes t/f

t

The function of activators and repressors may be modulated in three (3) main ways RNA polymerase binding, TFIID interactions, covalent modifications Binding of small effector molecules, protein-protein interaction, RNA polymerase binding Binding of small effector molecules, protein-protein interactions, covalent modifications Mediator complex binding, Protein-protein interaction, covalent modifications

Binding of small effector molecules, protein-protein interactions, covalent modifications