Answer:
Jonas Salk was awarded the Nobel Prize for discovering a way to vaccinate against polio in the United States in the 1950's. This allowed millions of school-age children to avoid crippling disease, and to swim during summer again, as polio was often spread in public swimming areas before.
The statement that best describes how the polio vaccine works is:
It triggers the immune system to produce antobodies to fight the disease-causing agent.
Explanation:
There are two main reasons for this answer. The first one is that every vaccine is aimed to introduce a controlled amount of antigenes to be accepted by the organism. These antigens are made after some studies were conducted in a lab and were obtained from substances that the human body can accept to train the immune system to develop an effective defense for the virus or bacteria on the matter. In our case, the polio vaccine works the same way and allowed to save many lives.
Answer:
With an experiment following the scientific method
Explanation:
The basic steps of the scientific method are: 1) make an observation that describes a problem, 2) create a hypothesis, 3) test the hypothesis, and 4) draw conclusions and refine the hypothesis. Critical thinking is a key component of the scientific method. Without it, you cannot use logic to come to conclusions.
Answer:
25.2
Explanation:
you add app all the numbers for the 1 column and divide by 7 then you do the same for the other column then subtract the totals from both to get the answer
Ans.
Genetic codes provide information for the protein synthesis as each code specifically codes a particular amino acid that gets joined in polypeptide chain during the process of translation.
Each genetic code is three letter code, made up of three nitrogenous bases. There are four different bases in DNA or RNA that make sixty four codes with different combinations, out of which sixty one code for amino acids and three act as stop codons.
Thus, nitrogenous bases are important in preserving the genetic codes.
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.
