What molecules form proteins when linked together with covalent bonds

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

How are fungi more like an animal? they have a cell wall. they are heterotrophs that absorb their food. they produce seeds and have membrane-bound nucleus. they use sunlight for photosynthesis.

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.