Essentials of Anatomy and Physiology

491

O O

O O

AAOAO

BBOBO

A

B

Dad

Type AB

Mom

Type O

Key: O

A

B

Gene for neither A nor B antigens

Gene for A antigen

Gene for B antigen

Figure 21–9. Inheritance of blood type (multiple
alleles pattern). See text for description.
QUESTION:If Dad has type AB blood and Mom is het-
erozygous for type A, is it possible that a child of theirs
will have a blood type that is different from that of both
parents?

X XcX

Y

X

Y XcY

XX

XY

Xc X

Xc X

Mom

Carrier of color blndness

Key: XX

Y

Xc

Dad

Normal color vision

X chromosome with gene for normal color vision

Y chromosome (has no gene for color vision)

X chromosome with gene for red-green color blindness

Figure 21–10. Inheritance of red-green
color blindness (sex-linked pattern). See text
for description.
QUESTION:If Dad is color blind and Mom
is not a carrier, what are the possible out-
comes for daughters and for sons?