The correct answer is D Fish ( someone asked me to explain why d is the answer) A sponge obviously doesn’t have a brain, a hydra is an organism and organisms don’t have brains ( hydra also doesn’t have eyes)
Rocks,water,pebbles = Abiotic
Fish =Biotic
In order to solve this problem we use these formula:
<span>p2 + 2pq + q2 = 1p + q = 1p = % dominant allele in the population
q = % recessive allele in the population
p2 = % homozygous dominant individuals
q2 = % homozygous recessive individuals
2pq = % heterozygous individualsFrom the given, we haveq2 = 21%Simply taking the square root,q = 4.58%</span>
Answer:
1. hydrogen; 2
2. it means two strands of DNA twisted around each other like a winding staircase