Which statement best defines epigenetics as introduced in the lesson?

• The study of changes in DNA sequence that cause mutations

• The science of how environmental influences turn genes on or off without changing DNA sequence

• The process of mapping all genes to determine variations

• The study of how proteins are made directly from DNA

Which mechanism is described as adding methyl groups to DNA, often silencing gene expression?

• Histone acetylation

• DNA methylation

• RNA splicing

• Chromosome duplication

Which environmental factors from the text is identified as a trigger for epigenetic changes after birth? (more than one correct answer)

• Genetic inheritance

• Diet

• Hormones

• Random DNA mutations

During pregnancy, why are folic acid and B vitamins important to epigenetics?

• They increase mutation rates to create diversity in the population

• They support methyl group production that can silence disease-causing genes

• They remove all epigenetic tags from histone tails and suppress mutations

• They permanently alter DNA sequences

What conclusion did geneticists reach after the Human Genome Project regarding many diseases and traits?

• They are primarily caused by the sequence of DNA bases

• They result only from inherited mutations

• Many are influenced by environmental factors affecting gene expression

• They cannot be explained by any biological mechanism

Which statement about epigenetic inheritance is supported by the material?

• Epigenetic changes cannot be passed between generations

• Parents’ experiences may lead to epigenetic changes that can be inherited by children

• Only mutations in DNA are heritable

• Epigenetic changes occur only during embryonic development and never later in life

What does it mean when a gene is "turned on" versus "turned off"?

• Turned on means the gene is mutated; turned off means the gene is repaired

• Turned on means the gene is being expressed to make RNA/protein; turned off means the gene is not being expressed

• Turned on means the gene is only present in some cells; turned off means it is absent

• Turned on means the DNA is replicated; turned off means replication stops

Which outcome is most accurate regarding the Human Genome Project (HGP)?

• It fully explained all human traits and diseases immediately

• It provided a map of genes but did not alone explain complex traits and led to increased interest in epigenetic regulation

• It showed that environment has no role in health

• It eliminated the need to study gene expression

How can epigenetics affect humans before and after birth?

• Only after birth through injuries

• Before birth through prenatal factors influencing gene expression, and after birth through environmental and lifestyle influences on gene expression

• Only before birth through DNA mutations

• Neither before nor after birth