Assuming that you are making the two chromosomes as homologous pairs. You would need to make the two chromosomes relative size because they represent the same genes. One chromosome is from the mom and the other from the dad. If you are making chromosomes for one person they can vary in sizes.
Oil sticks to birds preventing them from flying. Whales and dolphins and other creatures that use blow holes can get oil into their respiratory system, making it difficult to breathe. Animals can also ingest the oil. This can be fatal and/or deadly in the short or long term.