Answer:
The good ozone layer can be described as the stratosphere part of the atmosphere which protects the Earth from harmful ultraviolet radiations from the Sun. The good ozone layer is however in a serious depleting condition due to human activities.
On the other hand, bad ozone layer is the part of the troposphere which is polluted. Emissions of toxic gases from human activities is the leading cause of this kind of pollution.
Answer:
the top 2 from left to right are: petal and stigma(*).
The one that follows from top to bottom is anther(#) and the one below is the filament.(#)
to the right there is the style(*) and below there is the ovary(*)
to the left of that, the last one with no symbol is the sepal
the last 2 sentences in the bottom are pistil and stamen
Water vapour and gases such as oxygen and carbon dioxide are able to move across the egg shell through small openings called pores. The egg contains all the nutrients that the developing chick needs during the three weeks of incubation period.
Answer:
Hypocalcemia is defined as low level of calcium in the serum.
It could be harmful to an individual in the following ways:
Convulsions, arrhythmias, tetany, and numbness in the hands and feet and around the mouth occur due to lowered threshold for depolarization causing increased responsiveness.
Life-threatening complications- Laryngospasm and Cardiac arrhythmias can arise.
Effects on cardiac output include:
(A) Negative chronotropic effect, or a decrease in heart rate.
(B) Negative inotropic effect, or a decrease in contractility
Answer:
Biogeographic isolation causes changes in gene pools that result from populations being separated.
Explanation:
Biogeographical isolation consists in the separation of a population by a geographical barrier, giving rise to <u>subpopulations</u>.
With isolation, the subpopulations start to suffer different pressures from the environment and consequently the selected genes in one subpopulation will be different from the other subpopulation.
Due to the biogeographic isolation, the two subpopulations will be prevented from crossing and the differences between them will become more and more accentuated, and with that the <u>subspecies</u> appear.
Over time, these subspecies may become so different from each other that reproduction between them becomes impossible.
When this happens, reproductive isolation occurs and, consequently, the emergence of new species. When speciation occurs due to geographic isolation, it is called allopatric speciation.
