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: Always and always
Explanation:
Within any large animal population there is always a variety of traits seen in the population. When there is a large number of individuals in a population then there are chances that there a genetic diversity.
Sexual reproduction in the organism can lead to the genetic variation in the organism. There are chances to have more variation in the population having more organism.
Two different organism are genetically different and there are variety of traits seen in the two animals that belongs to different species.
Answer:
"Haploid" refers to any cell that has 23 chromosomes (half of the total 46). "Gametes" are specifically sex cells that have 23 chromosomes. "Diploid" refers to any cell that has all 46 chromosomes. "Zygote" is the result of two gamete (haploid) cells fusing, and becoming a diploid cell.
hope this helps!!:)
Explanation:
Animal Farm is showing the reality of politics by portraying it as something completely different, a farm. The book shows the hidden truth of politics.
Answer:
It depletes resources until there are no longer enough to sustain the population
Explanation:
