Answer:
Mitochondrial DNA is circular, so it doesn't shorten when it replicates unlike the rest.
Spermatogenesis produces<span> four </span>gametes<span>, while </span>oogenesis produces one with two to three polar bodies left over. because oocytes contain not only genetic material but also mitochondria.
Answer:
a. heart development.
Explanation:
As the third week of fetal development starts, the process of formation of blood vessels begins. Also, the splanchnic mesoderm in the head end of the embryo forms heart on days 18 and 19. Since it develops heart, this part of the mesodermal cells is called the cardiogenic area. The underlying endoderm sends the induction signals to these mesodermal cells to form a pair of endocardial tubes that gradually develop into a single primitive heart tube.
This primitive heart begins to beat by the end of the third week of development. Therefore, any drug that affects fetal development during the first 20 days of the pregnancy might affect the development of the heart.
Explanation:
energy flows in only one direction through an ecosystem.
Answer:
These organisms should be adapted to live in this enviroment, i.e., they need to have adaptations to breathe, to swim (fins), streamlined bodies to move through the water, to eat the food found in the region, etc. Moreover, in this environment, the diversity tends to be high because marine regions are often characterized by their richness.
