<span>The answer is Due to heating of the air by the engine exhaust. Contrails are formed when the hot exhaust of the plane engines is rapidly cooled by the cold air in the upper atmosphere. The water vapor in the engine exhaust, formed in the combustion of fuel, freezes immediately to ice crystals due to the low pressure and -36oC temperatures in the 8000 m altitude in which the planes cruise. </span>
Answer:
Explanation:
Vascular plants have tubelike structures that carry water, nutrients, and other substances throughout the plant. Nonvascular plants do not have these tubelike structures and use other ways to move water and substances.
Vascular plants are said to have a true stem, leaves, and roots due to the presence of vascular tissues. Non-vascular plants do not have true roots, stems, or leaves and the tissues present are the least specialized forms of tissue. Some examples of vascular plants include maize, mustard, rose, cycad, ferns, clubmosses, grasses. Some examples of non-vascular plants include moss, algae, liverwort, and hornwort.
How vascular plants work through osmosis
The xylem of vascular plants consists of dead cells placed end to end that form tunnels through which water and minerals move upward from the roots to the rest of the plant. Through the xylem vessels, water enters and leaves cells through osmosis.
How non vascular plants work through osmosis
Because non vascular plants do not have the xylem and phloem ystem, they absorb water right into their cells through their leaves when it rains or when dew falls. Internal cells get their water by passive osmosis. While, they use rhizoids to transport nutrients and minerals.
<span>Radiochemical dating is the answer!</span>
Answer:
The correct answer would be - 25%.
Explanation:
It is given that the Blue flower is dominant over the yellow flower which means Blue is represented by allele B here and allele b for yellow and Bb is a heterozygous case with a blue phenotypic character. Similarly, the Tall plant is dominant over short and represented by T and t respectively.
BbTt is a heterozygous condition and a cross with itself will produce :
Gametes: BT Bt bT and bt
BT Bt bT bt
BT BBTT BBTt BbTT BbTt
Bt BBTt BBtt BbTt Bbtt
bT BbTT BbTt bbTT bbTt
bt BbTt Bbtt bbTt bbtt
Here 4 out of 16 offspring are heterozygous for both traits represented by bold alphabets. Therefore the correct answer is 25%
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
