Explanation:
Watson & Crick discovered that DNA is composed of two (2) strands of DNA running antiparallel to each other. One strand is oriented in the 5’ -> 3’ direction while the other is oriented in the 3’ -> 5’ direction. The nitrogenous bases of the strands are found in between the two-strand backbones and they form hydrogen bonding with each other. Specifically, pyrimidines (Cytosine and Thymine) pair with purine (Adenine and Guanine).
The space between the strands is even throughout like a ladder with rungs of equal lengths. However during the twisting on the DNA helix, there are major grooves and minor grooves that form along the helix because of the nature of how the nitrogenous bases are attached to their respective strand. They do not project from their strands at 90 degrees.
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Answer:
Genotype ratio: 1, 1:1, 1:2:1
Phenotype ratio: 1, 3:1
Explanation:
Single gene pair cross is also known as monohybrid cross. This means that only one gene usually with two alleles is observed and it express one trait.
For example, if we name the gene for a certain trait with A, the possible genotypes are AA (dominant homozygous), aa (recessive homozygous) and Aa (heterozygous). Possible crosses are:
P: AA x AA
F1 : all of them are AA
The same is with aa x aa (all of the offspring are with aa genotype)
P: AA x Aa
F1: AA Aa AA Aa (genotype ratio 1:1) (phenotype ratio 3:1)
The same genotype ratio is in aa x Aa (offspring will have aa Aa aa Aa-(genotype ratio 1:1) (phenotype ratio 1:1)
P: Aa x Aa
F1: AA Aa Aa aa (genotype ratio 1:2:1) (phenotype ratio 3:1)
P: AA x aa
F1: Aa Aa Aa Aa (1)
Answer:
The black and yellow bird population would begin to starve and would be forced to find alternative food, or die off. This would then send ripples through the food web, causing almost every species to be effected by the grasshoppers being gone.
That their ancestors were related
