Pleas hel Which of the following explains the flexible nature of plant stems?
a. Cell volume of parenchyma cells
b. Thickness of cell wall in collenchyma cells
c. Lack of nucleus in sclerenchyma cells
d. Presence of cellulose in plant cell wall

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?

True or false: (a) the strings of little red dots represent carbohydrates. (b) the model is called a bilayer because there are two main types of molecules present, lipids and proteins. (c) the many black lines represent amino acid tails. (d) this model shows membrane transport. (e) the blue ovals are hydrophobic. (f) the blue ovals represent phospholipid heads.