Answer: More than 99 percent of all organisms that have ever lived on Earth are extinct. As new species evolve to fit ever changing ecological niches, older species fade away. But the rate of extinction is far from constant. At least a handful of times in the last 500 million years, 75 to more than 90 percent of all species on Earth have disappeared in a geological blink of an eye in catastrophes we call mass extinctions.
Though mass extinctions are deadly events, they open up the planet for new forms of life to emerge. The most studied mass extinction, which marked the boundary between the Cretaceous and Paleogene periods about 66 million years ago, killed off the nonavian dinosaurs and made room for mammals and birds to rapidly diversify
What is the scientific name of a panda a Ailuropoda melanoleuca
Answer:
The correct answer is - cell wall made up of cellulose that makes it crunchy.
Explanation:
In plant-based foods, the outer membrane is a cell wall that provides structure and supports the plant to stand erect and protect from the outer environment. The cell wall is mainly composed of cellulose that is a carbohydrate which is comparatively crunchy or tough to the animal protein with a fatty cell membrane that makes it chewier than the crunchy.
The composition of the protective layers of the plant cels and animal cell causes this difference in their texture.
