Nitrogen is the major nutrient required by grass and is used to
stimulate high growth rates and is key to achieving high yields, however
if too much nitrogen is applied this can have a negative effects on
quality.
High rates of nitrogen can also cause problems with silage
fermentation due to excess nitrate having a negative impact on the
fermentation process and will produce silage that is less palatable and
the animals will be less keen to eat it.
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Nitrate is generally taken up by grasses quicker than it is
incorporated into proteins and until used this excess known as luxury
uptake is stored in the leaves. Excess nitrate will be present if
insufficient time is allowed between application and mowing and can also
occur under conditions of poor growth eg low light levels, cool
temperatures. It is also a problem if there is a dry spell after
application, when nitrate cannot be taken up by the roots, followed by a
period of wet weather that results in luxury uptake. The plant cannot
convert it to protein quickly enough so it accumulates in the plant.
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High rates of nitrogen may cause a reduction in crop sugars as they
are used to provide energy for the increased rate of plant growth and
for the manufacture of plant proteins and this increased growth rate may
in turn lead to lower crop dry matter content although in practice this
is often not significant.
Excess nitrate can be avoided by following the Grassland Rule to apply nitrogen at the rate of no more than 2.5 kg N/ha/day.
Answer:
Contains large polytene chromosome that permit visual inspection of genomic events.
Were used to study the genetic effects of mutations.
Were used to establish the concept of chromosomal inheritance.
Explanation:
<em>Drosophila melanogaster </em>is a model organism that is used by scientists to study the genes and effect of a mutation on the genes. Drosophila is used as a model organism as it has a very short life cycle and the offspring can be produced in a short duration of time.
Because of these characteristics, Thomas Hunt Morgan wanted to study the factors of inheritance on the <em>Drosophila</em> and concluded in the form of the chromosomal theory of inheritance by the effect of mutation on genes that lead to linkage mapping.
Also, the salivary gland of fruit fly contains the polytene chromosome which allows us to look into the gene events.
Thus, the selected options are correct.
Answer:
cells in the germ linelineline
Explanation:
which go on to provide gametes, or egg and sperm cells.
Answer:
Various scientists describe asteroids in different ways:
- Some scientists consider it to be rocks which orbit around the sun.
- Other consider it to be small planets.
The majority of the scientists agree that asteroids might have come into existence at the time of solar formation. The parts which broke down during the formation of the solar system resulted in the formation of asteroids.
<u><em>Scientists believe that asteroids might not have a major function in the universe but studying them would be of great benefit. This is because as they are parts broken from the solar system, exploring them will let us know about some unknown features of the other solar system bodies. </em></u>
