Why should humans be concerned about rarity of species, not just extinction rates?.

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

1. in a certain species of plant, the color purple (p) is dominant to the color white (p). according the punnett square, what is the probability of and offspring being white? 50%25%0%100% 2. in a certain species of plant, the color purple (p) is dominant to the color white (p). according the punnett square, what is the probability of and offspring being white? 0%100%50%25%(picture 1 is for question 1, and picture 2 is for question 2)

The dense layer of connective tissue that surrounds an entire skeletal muscle is the