Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate. The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate. Such factors as stress, caffeine, and excitement may temporarily accelerate your heart rate, while meditating or taking slow, deep breaths may help to slow your heart rate.
Answer:
100%
Explanation:
In this problem, we have one gene (pea color) with two possible alleles (green and yellow).
Green is dominant over yellow, so the possible genotypes and phenotypes are:
- GG or Gg = green pea pods
- gg = yellow pea pods.
If an individual is true breeding it is homozygous for all genes under study.
The cross between true breeding plants is:
<h3>GG x gg</h3><h3 />
The green parent (GG) can only produce <em>G </em>gametes; the yellow parent (gg) can only produce<em> g</em> gametes. 100% of the offspring will have the genotype Gg (green).
Answer:
The weakest of all scientific findings are given by case studies.
Explanation:
Case studies are observational or descriptive studies focalized on the analysis of a particular object (an individual, place, event, etc.) in a specific situation. Beacuse of its descriptive nature, it does not provides information about cause-effect relationships and does not consider the effect of random variations. It is the weakest of all scientific findings.
Correlational studies involves measurements of at least two different variables and try to identify if there is a specific relationship between variables, it means if there is a specific trend in the variation of one variable as a response to the variation in the other one (for example, when the temperature of a given solution increases, the solubility of the solute also increase). Although this kind of studies does not provides information about cause relationships, the trend between variables are well stated.
Experimental studies are the ones in which a researcher makes sure of providing a controled environment and manipulates a particular variable to see responses of one or more different variables. These studies provides well supported information.
Epidemiological studies the purpose to analyze all the factors involved in an epidemic (causes, incidence, evolution, etc.). It includes observational and experimental studies that complement each other. Because of the importance of these reasearch on public health, their scientific findings are well stablished and supported.
Summarizing, the weakest of all scientific findings are provided by case studies.
