Answer:
A - 3:1
Explanation:
In order to determine what number of offspring will have attached earlobes, we must make a Punnett table. We know that attached earlobes are the dominant gene, and we know unattached earlobes are recessive.
| P | p
——————-
P | PP | Pp |
——————-
p | Pp | pp |
As we can see, only one out of the four squares has two recessive genes. Therefore, our answer would be A - 3:1.
Covalent bonds are formed when two atoms are able to <em>share</em> electrons.
Iroinic bonds are form when two atoms are <em> </em> electrons from each other to complete the bond. This results in a pair of ions.
<u>Covalent bonds:</u>
- Have a definite shape.
- Have a low melting point.
- At room temperature they are in a liquid or gas.
- They occur between two non-metals.
<u>Ionic bonds:</u>
- Have no definite shape.
- Have a high melting point.
- At room temperature they are solid.
- They occur between a metal and a nonmetal.