Answer:
The movement is caused by the convection currents that roll over in the upper zone of the mantle. This movement in the mantle causes the plates to move slowly across the surface of the Earth.
Explanation:
Answer:
The second one is correct
Explanation:
A leukocyte is responsible for the immune system
Answer:
C. CH4 + 202 – CO2 + 2H20
Explanation:
CH4+O2-CO2+H20
The above equation represents combustion of methane to produce carbon-dioxide and water.
One carbon atom is present on the reactant side as well as on the product side. Four hydrogen atoms are present on the reactant side and two hydrogen atoms on product side. In order to balance this equation, we would multiply water molecule by two. Now there are four atoms of oxygen in the product side but only two on reactant side, so we will multiply oxygen molecule by two on the reactant side. Now the equation is balanced.
The balanced chemical equation is:
CH4+202-CO2+2H2O
This equation obeys the law of conservation of mass as the mass of the reactants is same as that of the products.
Answer:
sympatric speciation
Explanation:
Different sympatric species have the same closest ancestor and live in the same area but inhabiting different niches.
The steps for sympatric speciation are:
- An ancestral species inhabit a geographic area.
- With time, different populations of the same species occupy different niches or microhabitats in this general area.
- As the microhabitats are different, they have different environmental pressures that are acting on each population.
- These pressures lead to the origin of differences between groups, which need to adapt to each environment
- Each population suffers genetic changes due to environmental conditions. These changes are inheritable.
- With time, these differences drive to the final complete divergence of populations, becoming different species and reproductively isolated.
In sympatric speciation, the interruption of genetic flow must be fast, and there must be differences in niches so no species can compete and displace the other species. <em>Speciation occurs in the same distribution area of the original species</em>. The new species originate in a place with no physical barriers but different environmental pressures.
In the exposed example,
- <em>The introduced Cichlid fishes 200 years ago</em> → Original species and the common ancestor between the new derivated species
- <em>The lake</em> → general geographic area
- <em>The main lake and the streams</em> → Microhabitats or niches with different pressures each
- <em>The groups are splitting into two genetically and physically different types of fishes. They do not mate. There is no genetic flow between groups.</em> → Speciation process.
In science, the practice of classifying organisms is called taxonomy (Taxis means arrangement and nomos mean method). The modern taxonomic system was developed by the Swedish botanist Carolus Linnaeus (1707-1778). ... To distinguish different levels of similarity, each classifying group, called taxon