Answer:
Either (1.) Fossils or (2) Radiometric dating.
Explanation:
Fossils are an obvious answer to this, but radiometric dating is the method most scientists use to find the age of rocks. Radioactive isotopes break down predictably, so the farther along this process is, the older the rock is.
Answer: CHANNEL PROTEINS provide openings in the plasma membrane for substances to flow through without changing structure, and CARRIER PROTEINS allow passage of substances through the plasma membrane after undergoing a subtle change in shape.
Explanation: They are described thus:
A channel protein is a protein that allows the transport of specific substances across a cell membrane.
Carrier proteins are proteins that carry substances from one side of a biological membrane to the other. Many carrier proteins are found in a cell’s membrane, though they may also be found in the membranes of internal organelles such as the mitochondria, chloroplasts, nucleolus, and others.
You need two recessive alleles (xx). If even one dominant allele is present, the dominant trait will show (Xx or XX will both result in the dominant trait showing). That’s why they’re called dominant traits, because they overpower the recessive traits. In order for a recessive trait to show you must have two recessive alleles.
