6D Gene Expression

Why is gene regulation necessary in human cells?

• To ensure that all genes are expressed in every cell

• To increase the production of hydrochloric acid in stomach cells

• To prevent the expression of unnecessary genes in certain cells

• To decrease the overall DNA content in each cell

Tags

NGSS.HS-LS1-4

What is an operon?

• A cluster of genes regulated together

• A type of enzyme that breaks down lactose

• A sequence of DNA that stops gene expression

• A protein that enhances gene expression

What role does RNA polymerase play in the operon model?

• It acts as a repressor to prevent gene expression

• It binds to the promoter to initiate transcription

• It breaks down lactose into simpler sugars

• It binds to the operator to block gene expression

What happens when lactose is not present in the environment of a bacterium?

• The repressor is inactivated, allowing gene expression

• RNA polymerase is blocked by the repressor, stopping gene expression

• Lactose binds to the repressor, changing its shape

• The operon is removed from the bacterium's DNA

How does the presence of lactose affect the Lac Operon?

• It activates the repressor, which then blocks the operon

• It binds to the repressor, preventing it from blocking the operon

• It increases the degradation rate of mRNA

• It decreases the affinity of RNA polymerase for the promoter

Who suggested that the environment selects individuals with advantageous traits?

• Frederick Clements

• Charles Darwin

• Hall

• Turesson

Tags

NGSS.HS-LS4-4

What term is used to describe populations of plants that occupy climatically distinct regions?

• Ecotypes

• Cenospecies

• Ecospecies

• Biomes

Tags

NGSS.HS-LS4-4

Which station experienced freezing temperatures during winter?

• Stanford

• Mather

• Timberline

• Sierra Nevada

Tags

NGSS.MS-ESS2-5

What did Clausen's team conclude about the adaptability of ecotypes to extreme environments?

• It depends on the plant's size.

• It is influenced by flower color.

• It is due to gene expression.

• It is dictated by ploidy number.

Tags

NGSS.HS-LS4-4

NGSS.HS-LS4-5

What barrier discourages gene exchange between ecotypes?

• Chromosome number

• Climatic differences

• Polyploidy

• Genetic mutations