The correct term for on female arctic fox would be "organism". Although it should be noted that this depends somewhat on the context of the environment.
Answer:True
Explanation:
Nerve impulse must reach a certain threshold in a neuron before action potential can be generated to intiate conduction of action potential.
Therefore if mutiple impulses are generated and these are not upto thresholds , no matter how strong the stimulI are-NO ACTION POTENTIAL WILL BE GENERATED.
THIS IS ALL OR NONE PRINCIPLE
The all or none hypotheses can be best explain with flushing of the water closet after using it. If required volume of water is not pumped into the water closet storage above, no matter how long the handle is push, FLUSHING WILL NOT TAKE PLACE.Thus the threshold volume of water must be met.
Chimpanzee for the first one
The red-legged frog breeds in ephemeral ponds from January through March. Its relative, the bullfrog, breeds in permanent ponds from late March through May. There are two pre-mating isolation mechanism at play here,
1. Ecological isolation: The habitats are different, hence the individuals of both the species do not meet. Ephemeral ponds are temporary ponds that develop during rainy days, while the permanent ponds are full of water throughout the year.
2. Temporal isolation: The time of mating is different for both the species to avoid contact between the individuals of closely related species. Red-legged frogs mate in January to March slot and the bullfrog in the March to May slot.
Answer: the correct answer is C) the hepatic portal vein.
Explanation:
The portal vein is not a true vein, because it conducts blood to capillary beds in the liver and not directly to the heart. It is a major component of the hepatic portal system, one of only two portal venous systems in the body – with the hypophyseal portal system being the other.