The answer would be D. Hope this helps!
Answer:
4
Explanation:
In the food chain that is presented there are four trophic levels. The first level is occupied by the phytoplankton, which is the producer, thus it is at level one on the energy pyramid. Second comes the shrimp, which is feeding on phytoplankton, but is prey upon by numerous other species, thus it is on the second level in the energy pyramid. In the third level of the energy pyramid we have the perch. It is a small carnivore, and it feeds upon the shrimp and many other small prey animals, but it is also preyed upon by many larger species. The pike and the osprey are occupying the fourth level in the energy pyramid. They are both predators, and they prey on on the likes of the perch and many other small fish and animals, but they are not at the top of the food chain, as they also have predators above them and prey on them.
Answer:
d.during only prophase I and involves exchange between chromatids of homologous chromosomes.
Explanation:
Crossing over is the event that occurs during the pachytene stage of prophase I of meiosis I and results in the formation of new gene combinations, that is, recombination. During pachytene of prophase I, the synapsed homologous chromosomes exchange the genetic segments between them.
To facilitate recombination, synaptonemal complex assists in pairing the homologous chromosomes together during the zygotene stage of prophase I. Zygotene is followed by pachytene. A cut in two non-sister chromatids of a homologous pair, exchange of the broken segments followed by ligation results in recombination. Prophase II does not include crossing over.
Answer:The answer is diffusion.
Explanation: Unicellular organisms excrete waste by diffusion.
Unicellular organisms are organisms that have only one cell. They are called single cell organisms because all their life processes such as reproduction, feeding, digestion, and excretion, occur in only one cell. An example of unicellular organism is paramecium.
Diffusion is the inactive movement of molecules from the region of higher concentration to the region of lower concentration.
At least 75% of the history of the earth
