This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Nude mouse is used in genetics because of the following properties -a) Absence of thymusb) Xenograft can be sustained for weeksc) Severe combined immunodeficiency mice is same as nude miced) they can generate mature T lymphocytes 
Select and explain. 
A. ac, B. ab, C. ad, D. bc
B: ab
Answer: B: ab 
Explanation: The genetic basis of nude mouse mutation is a disruption of the FOXN1 gene.
Characteristics of nude mouse mutation are:-


AR mutation of a nu locus on chromosome 11


Thymic aplasia


T-cell deficient
Normal B-cell function.
Phenotypically hairless.
Accepts xenograft and allograft transplantation
Insusceptible to graft-versus-host disease
No generation of cytotoxic effector cells


SCID mutation occurs on chromosome 16. SCID mouse has a thymus, lymph nodes and splenic follicles virtually devoid of lymphocytes.