Which of the following was most likely not present in creating the amino acids of early earth's waters of the past? a: nitrogen b: sulfur c: hydrogen d: ammonia

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?