Answer:
The Y chromosome is an accurate indicator of a person's external sex organs.
Explanation:
Since females have two X chromosomes while males have one X and one Y chromosome, if you are aware of the presence of a Y chromosome you can safely assume that a person is a male. Therefore, you can assume what external sex organs a male has.
Mutations are spontaneous and occur at random however there are some mutagenic agents which increase the chance of this happening such as radiation exposure. If it is a point shift mutation then only a few bases on the dna sequence are changed so only changes a few of the amino acids in that chain (such as inversion of a base). If its a frame shift then the base sequence is altered so much so that every amino acid from after that changes (such as deletion of a base) which can create things such as cri-du-chat syndrome which results from a piece of chromosome 5 is missing. Hope this helps:)
Answer:
1 , 11 and 111 are correct