eli5: if you inherit 50% of your genes from your father and 50% from your mother, what stops you from getting two of the same gene, and missing one? also why do siblings look different?

Question

eli5: if you inherit 50% of your genes from your father and 50% from your mother, what stops you from getting two of the same gene, and missing one? also why do siblings look different?

In: Biology

Answer 1

You get half from each, but you get half of their whole. What pieces will make this half is a bit random. 

Example:

Your father is a purple monster. His genes are red and blue. 

Your mom is a green monster. Her genes are blue and yellow. 

You’ll get one color from each parent. Your options are: 
* Purple like dad. Red from dad, blue from mom.
* Orange monster. Red from dad, yellow from mom.

* Blue monster. Blue from both. 
* Green monster like mom. Blue from dad, yellow from mom.

Your siblings can look like you, but they are most likely to not.