Biology question?

Here is my other question. Thankyou so much for your answers I appreciate it so much!





1. A student examines three leaf specimens from aquatic plants and makes the following observations:





Leaf A: very thin leaves, no stomata, few air spaces in the spongy mesophyll, and poorly developed xylem





Leaf B: broad leaves, upper epidermis has a thick cuticle, chloroplasts, and many stomata, large air spaces in the spongy mesophyll





Leaf C: waxy cuticle on upper and lower surface, stomata on both surfaces





Decide which leaf belongs to each of the following species and explain your reasoning.





Water lily, a floating aquatic plant


Cattail, an emergent aquatic plant (leaves in the air)


Elodea, a submersed (underwater) aquatic plant





Leaf A is probably _____, because


Leaf B is probably _____, because


Leaf C is probably _____, because

Biology question?
Leaf A is Elodea due to fact there is no stomata and few air spaces in spngey mesophyll...meaning it does not get carbon dioxide from the air as other plants do.





Leaf 2 has to be water lily as it only has 1 thick cuticle layer (bottom layer is in water and no need to stop water loss). It also only has stomata on the top of the leaf as this is the layer exposed to the air. The large spaces in the spongy mesophyll allow leaves to float on the surface.





Leaf 2 is Cattail as both surfaces has cuticle and stomata. This indicates both leaf surfaces are exposed to the air...





Simple huh! ??
Reply:leaf A is probably elodea because it has less stomata which is due 2 the factor that the plant is submerged and the poorly developed xylem is due 2 the factor that the plant is submerged


leaf B is probably water lily, because lotus belongs 2 the waterlily family which has broad leaves


leaf C is probably cattail because it has waxy cuticle so that 2 avoid water 2 fall on the stomata during gaseous exchange





hope it helps!
Reply:A : Cattail








B : water lily








C : Elodea
Reply:A is the underwater plant. One clue is the lack of stomata. Stomata are little pores in the leaves that allow oxygen to enter so the plant can undergo cellular respiration. However, if there were pores in an underwater plant, seawater would rush in. Second clue is the poorly developed xylem. The xylem transports water. Since this plant is immersed in water, it really doesn't need to transport it.


B is the floating plant. This type of plant faces two environments: the air and the water. The upper epidermis (layer) faces the air, and must have a method of obtaining oxygen. Thus, the upper surface has stomata. Further, in order to prevent desiccation (drying out), the upper layer must have a waxy cuticle. This prevents water from the plant from evaporating due to heat and low humidity. Chloroplasts are there to obtain the energy of photons via transference to chemical energy. The photon excites an electron in a photosystem, and this energetic electron goes on to fuel other reactions. The large air spaces in the mesophyll help the plant keep its shape.


C is the emergent plant. Both sides of this leaf are subject to the air, and thus both need to be protected from desiccation with a cuticle. Further, both sides need to obtain oxygen, so both have stomata.





To spur your grandson's interest, why not actually have him look at these leaves? Take him outside, to a pond or something. . .Have a picnic! It'll be fun.