The type of flashlights (c)
A pea plant with alleles 'tt' is classified as a homozygous recessive plant. Homozygous stands for two of the same alleles --so this would be either TT or tt. We are able to classify it also as recessive because lowercase letters represent the non-dominant alleles.
sperm is produced by the testes
First, a physical property just identifies it's state, how it looks, color, and that stuff. Let's work on finding that.
⇔ Ability to rust wouldn't work as a physical property. That one changes the substance, making it a chemical change. So, we know that this can certainly be our answer!
