When an individual muscle fiber receives a threshold stimulus, it contracts as much as possible. ... a threshold stimulus is the minimum amount of energy needed to make a muscle fiber contract.
...The origin of life on Earth is a set of paradoxes. In order for life to have gotten started, there must have been a genetic molecule.. something like DNA or RNA—capable of passing along blueprints for making proteins, the workhorse molecules of life.
The different number of maternal and paternal chromosomes possible will be 8. that is option A is correct.
Chromosomes are defined as the genetic material within the body. They are thread like structures within the DNA and are made of proteins. In general human body has 23 pairs of chromosomes out of which 22 are numbered while 1 is the sex chromosome. Gametes are genetic material that are generally haploid in nature and they carry only one chromosome along with them. According to the question, there are 6 diploid chromosomes present which means there are 3 pairs of chromosomes. So each gametes will have a total number of 3 chromosomal pairs irrespective of their type that is maternal or paternal. Therefore combination of maternal and paternal chromosomes are given by
Combination = 2ⁿ where n is pair of chromosomes and here n = 3
Combination = 2³ = 8
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Complete Question :
If an organism has a diploid number of 6 chromosomes, how many different combinations of maternal and paternal chromosomes are possible in its gametes?
A. 8
B. 12
C. 3
D. 16
E. 6
Stimulants are substances that all result in the increase of levels of dopamine in the brain, which is a neurotransmitter that affects attention and pleasure. What this means is that stimulants affect our brain and the way it works by changing the ways that nerve cells communicate.
Neurons (nerve cells) are the cells that have a role in transmitting messages from the brain to other parts of our body, and vice-versa, which is important for pain response, alertness, energy etc.
With long-term use, the use of stimulants would affect the central nervous system (speeding it up), the brain, and the functions necessary to live, like respiration, heart rate, blood pressure, body temperature. Levels of neurotransmitters like dopamine, serotonin, and GABA, which are responsible for the regulation of different processes, are also impacted, which creates a chemical disbalance ultimately resulting in behavioral changes, mood swings, altered attention, movement and energy, stress etc.
So the part of the body that is affected the most with the long-term use of stimulants like cocaine, nicotine, methamphetamine is the brain of course, which is where these substances have the most impact, but the impact on the central nervous system, autonomous nervous system, and neurotransmitter levels is significant.