Question

Many conditional homozygous deletions produce a tumor phenotype. Which of the following descriptions is incorrect? А. DNA polymerase-associated exonuclease --- mice are tumor prone because they have -100 times more unrepaired errors than wild-type mice during each round of DNA replication B. BRCA-mouse models have a tumor phenotype and chromosomal aberrations consistent with improper repair of DNA double strand breaks с. mucin-/- mice are tumor prone because they are incapable of assymmetric DNA strand allocation during stem cell replication D. MGMT-/- mice are tumor prone because they cannot directly repair alkylated (methyl, ethyl, etc) nucleotides OE MDR1-/- mice are tumor prone because they are unable to pump toxins out of cells

Answer 1

The incorrect description is option C. mucin-/- mice are not tumor prone because they are incapable of asymmetric DNA strand allocation during stem cell replication.

Step-by-step explanation:

Out of the given options, the incorrect description is option C. mucin-/- mice are not tumor prone because they are incapable of asymmetric DNA strand allocation during stem cell replication.

DNA polymerase-associated exonuclease (option A) causes an increased number of unrepaired errors during DNA replication, leading to tumor development. BRCA-mouse models (option B) have a tumor phenotype and chromosomal aberrations due to improper repair of DNA double-strand breaks. MGMT-/- mice (option D) are tumor prone because they cannot directly repair alkylated nucleotides. MDR1-/- mice (option E) are tumor prone because they are unable to pump toxins out of cells.

Answer 2

Many conditional homozygous deletions produce a tumor phenotype, the incorrect description is option C: mucin-/- mice are tumor prone because they are incapable of asymmetric DNA strand allocation during stem cell replication.

Step-by-step explanation:

Mucin is a type of glycoprotein that plays a role in the protection and lubrication of various tissues. While it is true that mucin-/- mice may have other health issues related to the absence of mucin, their tumor proneness is not directly linked to asymmetric DNA strand allocation during stem cell replication. This description is not supported by the given information and is therefore incorrect.

In conclusion, out of the given descriptions, the incorrect one is option C: mucin-/- mice are tumor prone because they are incapable of asymmetric DNA strand allocation during stem cell replication.