NAD +molecule
Explanation:
Krebs cycle and electron transport chain are important steps in cellular respiration.
In the Krebs cycle, there is a need of NAD+ molecule which is then in Krebs cycle reduced to form a NADH2 molecule.
NADH2 is also an energy currency. It , giving electron in electron transport chain and return to Krebs cycle as NAD+.
Now in the Krebs cycle, it is ready to take electrons again.
A trophies level pertains to the position of an organism in the food chain. Humans are the most dominant organism that belong to more than one trophies level. When we eat plants we become the secondary or the tertiary consumers.
Birds are also organisms that belong to more than one trophies level. When birds eat seeds they become the primary consumer, but when they eat insects they become the secondary or even the tertiary consumers.
Im also stuck on this im down to A and C
The evolutionary adaptation of the digestive tract of roundworms is the PSEUDOCOELOM.
The pseudocoelom is a partial fluid-filled cavity inside the roundworm. Its presence is a factor in the shape of the roundworm.
