Answer:
a. substantia nigra
b. substantia nigra (it is repeated)
Explanation:
Parkinson's disease is a neurodegenerative disease that is caused by the death of neurons that release the neurotransmitter dopamine in the <u>substantia nigra</u>, or locus niger, -a region of the brain that regulates brain circuits that give the 'orders' to initiate voluntary movements- .
The lack of this neurotransmitter leads to the occurrence of the main symptoms suffered by patients: decreased movements, muscle stiffness, postural instability and tremor. These failures are generated by the abnormal way in which neurons work in the absence of dopamine through a mechanism that is not known in depth.
It is the second most frequent neurodegenerative disease, after Alzheimer's disease, with a prevalence of 2% in people over 65 years. The characteristic symptoms of stiffness, bradykinesia and tremor are associated with losses of neurons in the substantia nigra and dopamine depletion in the striatum. There are large cytoplasmic inclusions, called Lewy bodies, which are the pathological mark of the disease and appear predominantly in neurons that contain melanin of the nigra substance. Genetic studies in a subgroup of families with Parkinson's disease with autosomal dominant inheritance found a locus on chromosome 4q-21 23 and a mutation in the gene that encodes a synaptic protein, α-synuclein.
Answer:
C and D
Ocean acidity was greater in 2010 than in 2000.
Heart disease is the major cause of death in the United States.
Explanation:
just took the question and those are the only two that are correct.
A good index fossil is one with four characteristics: it is distinctive, widespread, abundant, and limited in geologic time. Because most fossil-bearing rocks formed in the ocean, the major index fossils are marine organisms
Answer: DNA is a molecule made up of two strands, twisted around each other in a double helix shape. The two strands are complementary which have a 5 prime end and a 3 prime end. To understand this question you must first understand the steps that follow.
DNA Replication:
<u>Step one: </u>
DNA Helicase (unzips) separates the strands.
<u>Step two:</u>
DNA Primase starts the process and makes a small piece of RNA called a primer. This marks the starting point for the DNA.
<u>Step three:</u>
DNA Polymerase binds to the primer and will make the new strand of DNA. DNA Polymerase can only add DNA bases in one direction, from the 5 prime end to the 3 prime end.
- The leading strand is made continuously.
- The lagging strand does not run continuously because it runs in the opposite direction. Each fragment is started with an RNA primer. DNA Polymerase then adds a short row of DNA bases from the 5 prime to 3 prime direction. This results in okazaki fragments because it can only replicate in small chunks. The process is repeated.
<u>Step four:</u>
Once the new DNA is complete the enzyme exonuclease removes all the RNA primers from both strands of DNA.
<u>Step five:</u>
Another DNA Polymerase fills in the gaps that are left behind with DNA.
<u>Step six:</u>
DNA Ligase seals up the fragments in DNA, in both strands to make a continuous double strand.
<u>Final answer:</u>
DNA Replication cannot replicate at the same time due to the leading and lagging strand.
Good luck!
Explanation:
Conservation of Energy in Living Systems
Energy changes form as it flows through an ecosystem, but the total amount of energy in the system remains constant. Food chains show how energy flows in an ecosystem. ... The chemical energy stored in producers is passed to consumers, organisms at higher levels on the food chain.
