The Earth comprises many spheres of subsystems, which associate with each other to develop a composite and spontaneously changing system of the Earth. The processes taking place in the system of the Earth occurs on spatial scales changing from fractions of millimeters to thousands of kilometers, and on time scales, which varies from milliseconds to billions of years.
The examples of instantaneous scales are a rotation of the Earth, breathing, an earthquake.
The examples of long-term scales are making coal and plate tectonics.
The system of the Earth is featured by various overlapping cycles in which matter is recycled again and again. The cycles involve interactions between multiple spheres and systems. The examples of cycles are rock cycle, day and night, and seasons.
Volcanoes discharge a huge concentration of particulate matter into the atmosphere. These particles function as nuclei for the development of droplets of water (hydrosphere). The rainfall, that is, hydrosphere usually upsurges after an eruption, initiating growth of the plant (biosphere). Thus, volcanoes and volcanic activities are a good illustration of system interactions.
Answer: The correct answer is option a.
Explanation:
Prezygotic isolation is a mechanism by which mating and fertilization is prevented. Thus, it prevents the formation of a zygote.
It can be achieved by various reasons such as temporal differences (difference in mating seasons), habitat isolation, behavioural differences (different mating rituals such as different dance patterns, voice calls, et cetera), mechanical isolation, et cetera.
Thus, different breeding calls prevent the species to interbreed with each which ultimately prevent the formation of zygote formation.
Hence, it is a type of prezygotic isolation.
Answer;
- DNA
-Some additional proof of the endosymbiotic theory includes the similarity in DNA between bacteria and mitochondria and cyanobacteria and chloroplasts.
Explanation;
-According to the endosymbiotic theory; mitochondria and chloroplasts contain their own circular DNA, similar to DNA in Bacteria, Both mitochondria and chloroplasts are surrounded by two membranes: inner and outer membrane, mitochondria are about the same size as bacteria and also mitochondria appear to have been derived from purple bacteria and chloroplasts derived from photosynthetic bacteria.
