There are inner part of the stem and outer part of the stem; in a plant the inner part supports the movement of the water and nutrients. You stop the flow of the vital elements of plant growth when you snap the stem and this is the reason why the plant die due to starvation of the nutrients.
Evolution Due to environmental factors, It may not look it, but, needles are leaves, they collect solar radiation to produce glucose through the process of photosynthesis, however, needles are, some would say, evolutionary superior to leaves. Needles themselves hold in more water due to their dense wax coating, they are very difficult for insects and other organisms to eat, one because of their structure, and two because of their acidity, they can catch sunlight all year long due to their winter resilience( they don't fall, during the winter), and they have less surface area for wind to catch, which leaves them better protected from wind than most deciduous trees, however the surface area can also pose a larger problem for less surface area means less sunlight interception, therefore more are needed to compete against regular leaves. But.. I Digress... Plant needles are 'PROBABLY' initially the result of evolution of narrow leaves due to climate or environmental factors.
Sry its so long got carried away! Hope this helps xD
Answer:
Backbones
Spines
Eggs
Beaks
Explanation:
I listed a few since you didn't provide the answer list. Hopefully these are on your answer list.
Answer:
Option C
Explanation:
All of the following options are correct except option C. in the Meselson Stahl experiment, after the first round of replication, the DNA molecules made consisted mainly of one parental strand and one new strand each which is the DNA molecules of intermediate density (H-L). Then future replications will produce more of the low density L-L density. This form of replication is thus termed to be the semi conservative form of replication