Answer:
A. Mendel observed green and yellow pea pods in a 3:1 ratio because the F1 generation was heterozygous.
Explanation:
The two true breeding plants in the parental population were homozygous (that is what true breeding means). Therefore, their cross would lead to all heterozygous offspring (see attached punnet square). Green is the dominant characteristic, so all F1 plants had a green phenotype, but Gg genotype.
The F1 cross would therefore be Gg x Gg. See attached punnet square.
The genotypes in the F2 generation are 1 GG: 2 Gg: 1 gg 1
Therefore, the phenotypic ratio is 3 green pea pods (Gg or GG): 1 yellow (gg)
C. A higher amount of addictive chemicals are needed to get the same high when fewer receptors are present...
Answer:
Glucose
Explanation:
The brain is an energy-hungry organ. Despite comprising only 2 percent of the body’s weight, the brain gobbles up more than 20 percent of daily energy intake. Because the brain demands such high amounts of energy, the foods we consume greatly affect brain function, including everything from learning and memory to emotions.
Just like other cells in the body, brain cells use a form of sugar called glucose to fuel cellular activities. This energy comes from the foods we consume daily and is regularly delivered to brain cells (called neurons) through the blood.
Studies suggest the quality of the foods consumed over a lifetime affects the structure and function of the brain. For instance, the consumption of omega-3 fatty acids found in fish provides structural material to maintain neurons. Studies also suggest omega-3 fatty acids are essential for the transmission of information between brain cells. In contrast, foods that are rich in sugars and saturated fats have been found to promote oxidative stress, which leads to damage to cell membranes.
The food you eat also affects molecules in the brain that support cognition. Some foods, such as those with turmeric, support cognition by helping to maintain molecular events related to energy metabolism.
Recent studies suggest lifestyle choices that affect the metabolism of nerve cells, such as diet and exercise, may in some cases provide a non-invasive and effective strategy to counteract neurological and cognitive disorders.
The answer is C because it is the only one that makes sense to that question.