Answer:
B
Explanation:
once neurotransmitters are released into the synaptic cleft, it binds to its receptors at the postsynaptic membrane. voltage gated calcium channels open and allows calcium to flow in, an action potential is generated immediately and reaches the end of the axon
Gonads are the reproductive organs that produce gametes.
Gametes are also known as sex cells. They are produced by the gonads. In males, the gonads are the testes. The gametes that are produced by males are called sperm cells. In females, the gonads are the ovaries. The gametes that are produced by females are called egg cells.
The
statement that best supports that belief is “both have cell wall made
of cellulose, store food material as starch, and have chlorophyll a and chlorophyll
b”.
The green algae are a
large, informal grouping of algae consisting of the Chlorophyte and Charophyte
algae, which are now placed in separate Divisions. The land plants or
Embryophytes are thought to have emerged from the Charophytes.
The correct answer between all
the choices given is the first choice or letter A. I am hoping that this answer
has satisfied your query and it will be able to help you in your endeavor, and
if you would like, feel free to ask another question.
Answer and Explanation:
The Huntington disease is caused by a mutation in the gene that codifies for the Huntingtin protein (Htt). The mutation produces an altered form of the protein leading to the neuron´s death in certain areas of the brain.
The Huntington disease characterizes for being,
- Hereditary, passing from generation to generation. To express the disease, a person must have been born with an altered gene.
- Autosomal, affecting men and women equally, because the mutated gene is located on an autosomal chromosome.
- Dominant, which means that by getting only one copy of the altered gene coming from any of the parents, the receiving person will express the disease. The mutation in the gene dominates over the normal gene copy.
- Expressed by heterozygosis. Most people affected by the disease are heterozygous, with a normal copy and a mutated copy.
There are just a few cases all around the world (3% approximately) in which the disease is expressed with no family history. The progenitors are not affected by the mutation. These cases are very rare and are called <u>"de-novo" mutations.</u> A new mutation is spontaneously produced and it is not inherited from any of the parentals. It consists of an increase in the number of CAG repetitions. In a normal person, the number of CAG repetitions is less than 35. When there are 40 or more repetitions it occurs the disease. But when there are between 35 and 39 repetitions, the penetrance of the disease is incomplete. This is a "gray zone". Those alleles that fall in the gray zone are unstable and might produce the HD. Individuals with these unstable alleles have a tendency to increase the number of repetitions from generation to generation until the number reaches 40 repetitions and the person expresses the disease. This <u>usually occurs in the paternal germinal line</u>, as it is particularly unstable in sperm and probably meiosis greatly affects their instability, causing an increase in the number of CAG repeats.
Answer:
Pyruvate kinase
Explanation:
Yeasts convert glycerol and sugars into glyceraldehyde 3-phosphate (G3P) through independent pathways. Then, G3P forms pyruvate and, in some circumstances, pyruvate is converted in ethanol, which can be used as energy sources. If the mutation affects any reaction before G3P formation, it will only affect yeast growing either on sugar or pyruvate but not both.
Pyruvate kinase is the only enzyme on the list acting after G3P is formed and before pyruvate is formed. All other options are enzymes acting only in the formation of G3P from sugars. Meaning that only pyruvate kinase mutants will lack the ability to grow on both sugars and glycerol.
