Ageneticist studying fruit flies hypothesizes that short wings are a recessive
trait coded for by a single gene. which observation is most likely to have led
her to form this hypothesis?
f flies have wing lengths ranging from very long to very short.
g flies with long wings are less likely to survive.
h flies with long wings can produce offspring with short wings.
j flies with short wings prefer to mate with flies with long wings.

H Flies with long wings can produce offspring with short wings.

Explanation:

For example, if we name the gene for the wings length with A, then the fruit flies with short wings have the genotype aa (recessive homozygous), while those with long wings can have either AA (dominant homozygous) or Aa (heterozygous) genotype. So, if two fruit flies with long wings and Aa genotype are crossed:

P: Aa  x  Aa

F1: AA Aa Aa aa

There is a 25% chance that offspring will have short wings.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation:

the answer is "a.) well–developed vascular system."

explanation: