Water then moves from cell to cell through the root cortex by osmosisalong a concentration gradient; this means that each cell is hypertonic to the one before it. In the centre of the root the water enters the xylem vessels. Water may move by diffusionthrough the cell walls and intercellular spaces.
Phenomena such as star explosions, neutron stars, black holes etc. are studied with the help of extremely powerful and sensitive telescopes.
These sophisticated instruments are able to see more than our own eyes can. Thus, they detect wavelengths outside of those found in our visible spectrum, such as X-rays etc.
The most sophisticated telescopes are those that are placed in space such as the Hubble or Spitzer Space Telescope. In this way, these instruments are able to circumvent the Earth's atmosphere that may block the view of the sky. Thus, in space, they have the optimal conditions to observe and study in detail such phenomena.
Answer:
The answer is 'D'- Their arm bones have the same structure, but not function. These are homologous structures.
Explanation:
Homologous structures are those which share a basic common structure but perform different function. The hand of a human performs functions like <em>writing, cutting, washing, chopping</em> etc. The wings of a bat are used for the purpose of <em>flying</em>.
Also, <em>a dolphin's flippers, a bird's wing, a cat's leg</em> are all <u>homologous structures</u>. The structures which are homologous have the following features:
- They share a <em>common origin</em>
- Their <em>anatomy</em> is similar
- They have a <em>similar pattern of development</em>.
C. Convection currents assist in the transfer of thermal energy from warmer climates to cooler climates.
"Water quality" may include the amounts of dissolved oxygen
and the levels of algal growth, pollutants which may be present and the pH level. Water quality effects also which types of organisms can
survive in a body of water.
Shellfish require a high level
of dissolved oxygen and their abundance is an indication of good water quality. Shellfish are sensitive to changes in the ecosystem and they cannot easily escape changes in the water quality. These are one of the reasons why shellfish are good indicators of water quality.