HYB: 201 -- ANSWERS to Seedling Evaluation
- To: Multiple recipients of list <i*@rt66.com>
- Subject: HYB: 201 -- ANSWERS to Seedling Evaluation
- From: S* M* <7*@compuserve.com>
- Date: Wed, 1 Apr 1998 11:01:03 -0700 (MST)
>From the problem posed involving
one blue and three white seedlings:
All three white seedlings are
genetically different. I'm using w1
and w2 simply to indicate two types
of recessive whites. I did not provide
enough information to enable you to
determine which types they are.
WHITE ONE is homozygous for w1. =
It probably has no more than one =
dose of w2, because it produced =
only blues when crossed with WHITE TWO.
It has no dominant inhibitor.
WHITE TWO is homozygous for w2.
It probably has no more than one =
dose of w1, because it produced =
only blues when crossed with WHITE ONE.
It has no dominant inhibitor.
WHITE THREE is heterozygous.
Doses of w1 and w2, if any, =
can't be determined.
It has one dose of the dominant =
inhibitor.
OLD BLUE is heterozygous. =
It probably doesn't have even
one dose of w1 -- if it did, we'd =
expect about three white seedlings
out of a hundred offspring when it =
was crossed with WHITE ONE.
It probably has two doses of w2 -- =
to be able to produce white =
seedlings when crossed with =
WHITE TWO. =
It has NO dominant inhibitor -- =
otherwise it wouldn't be blue.
Followup:
How would you use named
cultivars of known types to
test these seedlings and
identify the type of recessive
involved in WHITE ONE and
WHITE TWO?
Sharon McAllister
73372.1745@compuserve.com
