Answer:
180
Explanation:
they divide it into 180 degrees
Answer:
The correct answer is A. Fossil fuels are cheaper than alternative forms of energy
Explanation:
Fossil fuels are made from organic matter of dead animals and mainly plants who were buried in the soil over hundred and thousand of years. We use fossil fuels because they are the best source to provide energy in the current time.
Fossil fuels are easily available and are present in very large amount which is the main reason for it to be cheaper. Fossil fuels like coal, petroleum or natural gas are more cheaper and efficient than alternative forms of energy like solar or wind energy.
But in future these fossil fuel will not be there and alternative forms of energy will become the primary and cheaper source of fuel.
<u>Answer:</u>
Recent evidence suggest that feathers evolved from scales and suggest that 'feathers and pycnofibers' could be homologous.
<u>Explanation:</u>
- One of the major difficult issue related to bird evolution is the evolution of feathers.
- Feathers are considered as the most 'complex integumentary structures' which are found in vertebrates.
- Evolutionary developmental biology suggests that the 'planar scale structure' is been modified for developing into feathers by 'splitting' to form web like structures.
- Scales and Feathers consist of 'two distinct form of keratin' so it was thought that 'each type was exclusive skin structure' but recent study suggests that they are developmental expressions of same skin structures.
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.
