<span>The Basics on Genes and Genetic Disorders</span>
B- black allele;
b- brown allele;
The parental cross is true-breeding because both the male and the female are homo zygotes, so: BBx bb
The F1 generation will be all black heterozygote: Bb
The F2 generation will be between mice of the F1 generation and they all have the same genotype:Bb xBb
In this cross it would result in:
1/4 of the plants being black homozygote-BB 25%
2/4 of the plants being black heterozygote- Bb- 50%
1/4 of the plants being brown homozygote- bb- 25%
answer: 25%+25%=50% are homozygotes
Meningitis is an inflammation of the membranes (meninges) surrounding your brain and spinal cord. ... Most cases of meningitis in the United States are caused by a viral infection, but bacterial, parasitic and fungal infections are other causes. Some cases of meningitis improve without treatment in a few weeks.