For the trait that is coded by a recessive allele to be expressed, the must be homology, which means that an offspring has to inherit that recessive allele from both its parents.
A dominant allele will dominate over the recessive allele, so for the trait coded by a dominant allele to be expressed, the offspring only needs to inherit the allele from one of its parents.
For example: "R" is brown eyes, "r" is blue eyes. Now you get one R from each of your parents. RR (homozygote) = brown eyes Rr (heterozygote) = brown eyes rr (homozygote) = blue eyes
If a plant uses up all of the carbon dioxide this would just keep makeing oxygen or its known as photosynthesis. I'm NOT a 100% sure If this is is the correct answer or not.
The hydroponics root system to grow is that they use the same method as the soil root but the root volume for hydroponics is highly restricted and they don't need to use too much energy to grow.
