The earth's atmosphere consists mainly of nitrogen and oxygen with smaller proportions of other gases such as carbon dioxide. The amount of carbon dioxide in the atmosphere is maintained through a balance between processes such as photosynthesis, respiration and combustion. However this balance is being affected by human activities which are polluting the atmosphere.
The proportion of these gases in the atmosphere is as follows: nitrogen is the most abundant at 78%, oxygen is next at 21%, while others include carbon dioxide at 0.037% and argon at 0.9 % .
Answer:
All of the statements are true.
The X chromosome is one of the two sex chromosomes of humans and some animals (the other sex chromosome is the Y chromosome). Men have a single X chromosome and women two X chromosomes.
Diseases whose gene is localized on the X chromosome are most often transmitted in the X-linked recessive mode; some are transmitted on the dominant mode related to the X.
In this mode of inheritance, the morbid allele behaves like a recessive trait.
Women heterozygotes are not affected but can transmit the disease; they are aid to be conductive of the disease.
The disese is only manifested in male subjects (XY) with only one copy of the gene (hemizygous subjects)
Answer:
- In terrestrial environments: increasing CO2 levels cause an increased photosynthetic rate
- In aquatic environments: increasing CO2 levels cause an increase in water acidity
- In both terrestrial and aquatic environments: increasing CO2 levels lead to an overall increase in the average temperature (global warming)
Explanation:
In terrestrial ecosystems, rising carbon dioxide (CO2) levels increase the rate of photosynthesis (since CO2 is one of the reactants in photosynthesis), thereby also increasing plant growth. Moreover, in aquatic ecosystems, rising CO2 concentrations increase the levels of this gas dissolved on the surface of the oceans. This increases the acidity of the oceans, thereby modifying habitats and food web structures. The increasing acidity of the oceans also reduces the amounts of carbonate, which difficult for aquatic species (e.g., corals) to form their shells/skeletons. Finally, CO2 is a greenhouse gas that contributes to the increase in the average temperature by absorbing solar radiation that would otherwise have been reflected by the Earth's surface, and this increase in the temperature negatively affects life in both terrestrial and aquatic environments.
