Breaking cells open to release the DNA.
Separating DNA from proteins and other cellular debris.
Precipitating the DNA with an alcohol.
Cleaning the DNA.
Confirming the presence and quality of the DNA.
Coevolution happens when the genetic development between two or more species affects the evolution of each other. An example would be hummingbirds and bird-pollinated (ornithophilous) flowers. The ornithophilous flowers give nourishment to the birds with their nectar that has high sugar content. The birds in return aids in the pollination of these flowers.
1. Carbohydrates
(There are 3 sources of calories (or energy), which are also known as macronutrients: carbohydrates, protein, and fat.
Of these three, carbohydrates are the body’s preferred source of energy. Carbohydrates break down into glucose, which is an immediate source of energy.)
2.
A. Bone is not a type of human body tissue.
(The human body does has 4 types of tissue: Epithelial, muscle, connective and nervous tissue).
I believe that the youth movement originated with the baby boomers, the huge generation born after the world war II. By 1970, 58.2 % of the population in America was under the age of 35 years. The economic boom of the 1950s meant more families could afford to send their children to College. College life gave the young people a sense of freedom and independence. It was on college campuses across the nation that youth protest movements began and reached their peak.
Question: Does geographic distance between salamander populations increase their reproductive isolation? To answer this question, researchers studied populations of the dusky salamander (Desmognathus ochrophaeus) living on different mountain ranges in the southern Appalachian Mountains. The researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. Four mating combinations were tested for each pair of populations (A and B)—two within the same population (female A with male A and female B with male B) and two between populations (female A with male B and female B with male A). The proportion of successful matings for each mating combination was measured. For example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. Then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). The reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (AA + BB) minus the sum of the proportion of successful matings of each type between populations (AB + BA).
The table (Figure 1) provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.
Part A - Understanding experimental design
What hypothesis did the researchers test in this study?
Answer:
"Reproductive isolation increases with geographic distance between dusky salamander populations"
Explanation:
The mechanisms of reproductive isolation are a assemblage of evolutionary mechanisms, behaviors and physiological procedures dangerous for speciation. They avert followers of dissimilar types from manufacturing offspring, or confirm that any offspring are germ-free. While in allopatric speciation the reproductive isolation is resolute superficially by the spatial isolation of populations, during sympatric speciation specific groups of persons create distinct mating organizations with self-like persons while distribution the similar home with the rest of the unique inhabitants.
