Non-mendelian inheritance - Epigenetic inheritance: genomic imprinting

7 important questions on Non-mendelian inheritance - Epigenetic inheritance: genomic imprinting

When does genomic imprinting happen?

Genomic imprinting happens prior to fertilization, it involves a change in a single gene or chromsome during gamete formation.

What is monoallelic expression?

Monoallelic expression in the case of genomic imprinting, refers to the phenomenon that only one of the two alleles of a given gene is transcriptionally expressed.

What would be the outcome of a cross between a heterozygous female and a homozygous male with two normal copies of the Igf2 gene?

All of the offspring would be normal because they would inherit an active copy of the gene from their father.
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

Explain why the erasure phase of imprinting is necessary in eggs.

Erasure allows eggs to transmit unmethylated copies of the gene to the offspring.

What are the phases of genomic imprinting?

The phases of genomic imprinting are:
  • The establishment of the imprint during gametogenesis;
  • The maintenance of the imprint during embryogenesis and in adult somatic cells;
  • The erasure and reestablishment of the imprint in the germ cells.

What is DNA methylation?

DNA methylation is the attachment of a methyl group onto a cytosine base.

On the left side of this figure, explain why the offspring does not have Prader-Willi syndrome but does have Angelman syndrome.

The offspring on the left side did not receive a copy of either genes from the mother. The father silences the AS gene, so the offspring has AS because he or she does not have an active copy of the AS gene. By comparison, the offspring does receive an active PWS gene from the father, which prevents him or her from having PWS.

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo