Question: In fruit flies, red eyes are dominant over sepia eyes. A male with red eyes is crossed with a female with sepia eyes producing first generation offspring that all had sepia eyes. What does this indicate about the flies that were crossed?
Answer: The male is heterozygous and the female is homozygous recessive for the trait.
Hypothesis: the male fruit fly is heterozygous dominant and the female fruit fly is homozygous recessive
Supporting facts: sent1: red eye is a dominant trait in fruit flies sent2: sepia eye is a recessive trait in fruit flies sent3: if a recessive trait is expressed, then the organism only contains recessive genes for that trait sent4: if an offspring has a recessive trait , then each parent has at least one recessive gene sent5: the male fruit fly has dominant red eyes sent6: a fruit fly is a kind of organism sent7: the dominant red eye male fruit fly is one of the parents sent8: if an organism has dominant trait and one recessive gene for that trait, then the organism contains both dominant and recessive genes sent9: a red eye fruit fly crossed with sepia eye fruit fly produces offspring with sepia eye sent10: parents produces offspring sent11: a heterozygous organism contains both dominant and recessive genes sent12: a homozygous recessive organism contains only recessive genes sent13: the female fruit fly has recessive sepia eyes
Reasoning: [BECAUSE] red eye is a dominant trait in fruit flies [AND] sepia eye is a recessive trait in fruit flies [AND] a red eye fruit fly crossed with sepia eye fruit fly produces offspring with sepia eye [INFER] int1: a dominant red eye male fruit fly crossed with a recessive sepia eye female fruit fly produces offspring with recessive sepia eye [BECAUSE] int1 [AND] parents produces offspring [AND] if an offspring has a recessive trait , then each parent has at least one recessive gene [INFER] int2: each parent fruit fly will have at least one recessive gene [BECAUSE] int2 [AND] the dominant red eye male fruit fly is one of the parents [INFER] int3: the male fruit fly has at least one recessive gene [BECAUSE] int3 [AND] the male fruit fly has dominant red eyes [AND] a fruit fly is a kind of organism [AND] if an organism has dominant trait and one recessive gene for that trait, then the organism contains both dominant and recessive genes [INFER] int4: the male fruit fly has both dominant and recessive genes [BECAUSE] int4 [AND] a heterozygous organism contains both dominant and recessive genes [AND] a fruit fly is a kind of organism [INFER] int5: the male fruit fly is heterozygous dominant for the trait [BECAUSE] the female fruit fly has recessive sepia eyes [AND] if a recessive trait is expressed, then the organism only contains recessive genes for that trait [AND] a fruit fly is a kind of organism [INFER] int6: the female fruit fly only has recessive genes for sepia eyes [BECAUSE] int6 [AND] a homozygous recessive organism contains only recessive genes [AND] a fruit fly is a kind of organism [INFER] int7: the female fruit fly is homozygous recessive for the trait [BECAUSE] int5 [AND] int7 [INFER] int8: the male fruit fly is heterozygous dominant and the female fruit fly is homozygous recessive