Answer:
The food type changes in a given environment, then the amount of each type of bird beak will changes as birds with beaks more suited to the available food will consume more successfully over time. The independent variable of the lab is the type of food that is available to the birds.
Explanation:
Sediment discharge was historically approximately 270 million cubic meters/year of suspended load and 130 million cubic meters/year of bedload. This has decreased 80% since 1850 and can be divided into three periods: historical period (pre 1900), pre-dam period (1932-1952), and post dam (1963-1982). Suspended sediment loads declined 43% between the historical and pre-dam and 51% from pre-dam to post-dam periods. The size of sediment also decreased drastically including a 72% decrease in the sand fraction. Most of this is due to dams on the tributaries acting as sediment traps primarily for the coarser sediments. Large-scale land clearing for agriculture contributed to increased sediment loads in the historic period.
An example of an dramatic environmental event can be deforestation, or it can be animals losing their homes.
Answer: Membrane transport proteins are specific and selective for the molecules they move, and they often use energy to catalyze passage. Also, these proteins transport some nutrients against the concentration gradient, which requires additional energy.
Explanation:
Answer:
c) Breaks down and inactivates acetylcholine
Explanation:
Acetylcholinesterase is an enzyme that is required for termination of acetylcholine activity in the synaptic cleft. The enzyme is present in the extracellular side of the motor endplate membrane and breaks down the acetylcholine into acetyl and choline.
In the absence of acetylcholine, the muscle fibers resume their resting stage. Therefore, acetylcholinesterase activity is required for the normal functioning of muscles and nerve cells that use acetylcholine as a neurotransmitter.
