Researchers selected candidate genes by identifying homozygous tracts shared by all three siblings along with the parental phenotype, this type of study is applied for the inheritance of recessive genes. Since the recessive genes can not be expressed in heterozygous genotype, the back tracking of carriers and homozygous recessive individual will help understand its inheritance pattern. The inheritance of dyt2 can be autosomal recessive. It is usually passed on to progeny of two carriers.
Answer:
B
Explanation:
Neurotransmitters such as acetylcholine, epinephrine are important at a neuron-neuron junction called synapses. When an impulse reaches the end of one neuron, at the synapse, it causes the release of neurotransmitters from synaptic vesicle that diffuse across the synapse and when they bind to their reports on the other end. An impulse is then generated on the subsequent neuron that travels down the axon to the next synapse.
The autotrophs are the primary producer in the food chain and they are the ones who initiate the food chain. They produce food by using sunlight or sometimes chemical energy or reactions. They primarily use carbon dioxide, sunlight and water to form sugars or carbohydrates which become their energy source. They use the process of photosynthesis or chemosynthesis to generate food. Examples of autotrophs are green plants, green algae, bacteria.
Heterotrophs cannot make their food via sunlight or other inorganic sources and hence are dependent on the autotrophs or other animals. The heterotrophs have been ranked as secondary and tertiary consumers and cannot be producers. They consume the organic products made by autotrophs to obtain energy for various metabolic and biological activities. The heterotrophs can be herbivore, carnivore, fungi, parasitic plants.
Some are photo-hetrotrophs, who use light as energy but cannot use carbon dioxide as the carbon source since they cannot fix the carbon like autotrophs.
By tar, I think you mean nicotine. (I Hope). It affects the nerve signals that regulate breathing.