Answer:
Cystic fibrosis (CF) is more common in Caucasian individuals and is inherited with an autosomal recessive inheritance pattern.
Explanation:
Cystic fibrosis (CF) is a condition of genetic origin, which affects organs such as the lungs, pancreas, intestine and liver. CF is characterized by the production of very thick and viscous mucus, and promotes the formation of cysts and fibrosis of the affected organs.
CF is an inherited disease that is transmitted in an autosomal recessive pattern, that is, the altered gene is required to be on both chromosomes of the allelic pair, in order to be expressed.
It is a very common disease in Caucasian individuals, especially those of European descent.
Answer:
the observations that chloroplasts and mitochondria resemble bacteria
Explanation:
The Endosymbiotic Theory is a theory that enables us to understand the origin of eukaryotic cells. The Endosymbiotic Theory posits that the mitochondria and chloroplast, which are organelles found in the eukaryotic cells, were once prokaryotic microbes that were first ingested by amoeba-like organisms and subsequently evolved by developing a symbiotic relationship with them. Some of the most important lines of evidence that supports this theory are: 1-chloroplasts and mitochondria resemble prokaryotic cells, i.e., they have a similar size, replicate by binary fission and there are unicellular eukaryotic protists that have filamentous temperature-sensitive proteins at their division plane (similarly to bacteria), and 2- chloroplasts and mitochondria are organelles with their own DNA and their own ribosomes (which are similar to those of bacteria).
The question provided is not complete as it lacks the group of choices, however the group of choices are given as follows:
A. A contraction fails to occur because an action potential is not generated in the muscle cell.
B. A contraction fails to occur because this toxin directly prevents ion release from intracellular stores.
C. A contraction fails to occur because neurotransmitter release by the motor neuron is blocked at the neuromuscular junction.
D. A contraction fails to occur because this toxin prevents cross bridge formation and thereby directly prevents contraction.
E. C and D are both true
Answer:
The correct answer is option A : A contraction fails to occur because an action potential is not generated in the muscle cell.
Explanation:
A muscle contraction takes place when action potential bring to muscles by nerves, which is traveled with the help of motor neuron and imitated the muscle contraction.
Acetylcholine or Ach is a chemical messenger to bring the nerve impulses between a nerve and a muscle. If the receptor is block with applying toxin muscle will not contract as ACh will not be able to propagate the nerve impulse to the muscle so there will be no action potential.
The correct answer is option A : A contraction fails to occur because an action potential is not generated in the muscle cell.
The placenta forms at 8 weeks, and develop for 6 weeks. hope this helps
