Answer:
X-linked is a trait where a gene is located on the X chromosome. Humans and other mammals have two sex chromosomes, the X and the Y. In an X-linked or sex-linked disease, it is usually males that are affected because they have a single copy of the X chromosome that carries the mutation.
Explanation:
Answer:
The answer is B. Some organic molecules, including amino acids, could have been produced from chemical reactions on early Earth.
Explanation:
Miller-Urey Experiment:
The Miller-Urey experiment was an attempt to explain the origin of life on Earth. Miller-Urey simulated the primordial soup i.e. the environment of primitive Earth to prove the spontaneous generation of organic molecules. The conditions they introduced included:
- A methane-ammonia-hydrogen and water mixture that exactly simulated the primordial soup.
- A spark of 70,000 volts that simulated lightening.
- A temperature of 800 degree Celsius.
Observations:
- After running for 18 days, the final solution was examined for presence of organic molecules.
- Miller-Urey observed that most of the methane and ammonia had been consumed and the mixture contained carbon monoxide and nitrogen.
- The solution further contained 25 amino acids (mainly, glycine, alanine and aspartic acid)
, several fatty acids
, hydroxy acids and amide products.
The experiment concluded that simple organic compounds such as amino acids could have been formed through spontaneous generation under the Earth's primitive environmental conditions.
Answer:
B. Prefrontal Cortex
Explanation:
The prefrontal cortex is in the front of your head and it is affected when you drink liquor or do drugs. That is why when you are drunk you don't have good judgement. When you do drugs, your prefrontal cortex is eaten away and that is why people with drug problems have trouble remembering things.
Hope this helps, have a great day/night!
Answer: options D and E
Explanation:
The heartbeat in a human is mostly initiated by the sinoatrial node (SA node also known as the heart's natural pacemaker. Made up of a specialized bundle of cell that receives an impulse causing contraction of the atria wall allowing blood to flow into the ventricles. During systole, the ventricles are not relaxed but contracted to allow for bloodflow out of the ventricles to the aorta which is the largest artery in the human body.