Answer:
The given situation is an example of <u>density dependent factor</u>.
Explanation:
The density dependent factors are the factors that regulate the growth of a population. It is defined as the factors whose effects on the growth or size of a given population vary with the population's density. The various types of density dependent limiting factors are diseases, migration, safe drinking water, food availability, migration etc.
<u>Therefore, the given situation is an example of density dependent factor.</u>
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.
These factors are essential for the growth and life span of the population of species in an ecosystem. The larger the space, the more light it obtains, and the more food the area produces; the larger the population of species in an ecosystem. having less space, light, and food, the results would be vice versa.
Nucleus, ribosomes, endoplasmic reticulum, and <span>Golgi apparatus.</span>
