Answer:
All the above
Explanation:
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports fluids between the roots and the shoots in the xylem and phloem, stores nutrients, and produces new living tissue.
Stems have four main functions which are:[1]
Support for and the elevation of leaves, flowers and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
Transport of fluids between the roots and the shoots in the xylem and phloem(see below)
Storage of nutrients
Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.
B. It describes the day-to -day condition of the atmosphere of Earth.
Answer:
2
Explanation:
DNA is tightly packed up to fit in the nucleus of every cell. As shown in the animation, a DNA molecule wraps around histone proteins to form tight loops called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin
Answer:a positive feedback
Explanation: positive feedback is a type of feedback mechanism employed by the body,in which an output is enhanced or acclerated.
In contrast to negative feedback where the body regulates it's internal conditions by reducing the effect of a stimuli,In positive feedback ,the body enhances the effect of the stimuli.
It is not common as negative feedback in homeostasis.
An example is the increasing release of oxytocin to promote contractions during childbirth,until the child is born.
Another example is the accumulation of blood platelet , in the site of blood vessels injury to
cause blood clotting.
