Which blood vessels have thick, muscular, and elastic walls?

Sydney drew a flow chart to illustrate the nitrogen cycle. which labels best complete the flow chart? x: producers undergo photosynthesis. y: nitrogen compounds are released into the air. x: nitrogen compounds are released into the air. y: producers undergo photosynthesis. x: free nitrogen is in the atmosphere. y: producers absorb nitrogen compounds through their roots. x: producers absorb nitrogen compounds through their roots. y: free nitrogen is in the atmosphere.

2. if scientists identify an animal with bilateral symmetry and no segmentation, which phylum can it definitely not belong to? a. roundworms b. annelids c. mollusks d. flatworms

Turtle hatchling survivorship rate is low in many turtle species due to predation. amanda researched the predatory rate on a species of turtle eggs in the red river. the eggs were harvested from trapped turtles and the egg's cloaca film (reproductive discharge) was either washed off or left on once gathered. research suggests that predators use the female's cloaca scent to locate the eggs. the eggs were only handled when wearing gloves and then reburied along islands where the turtles were trapped. the nests were monitored by cameras and manually on foot and data on nest predation were recorded. a. based on the experimental design, what is the dependent variable? b. based on the experimental design, what is the independent variable? c. based on the experimental design, what is the control?