Answer:
So they are lighter and move quicker.
Explanation:
With the small wings and bodies birds have it would be hard for them to escape predators and lift their own weights if their bones were dense like humans' bones. The hollow part of the birds' bone is connected to their lungs so they have enough oxygen to fly easily. Hope this can help you! :)
Answer:
50% will be normal and 50% will be carriers
Explanation:
Color blindness is a reduced ability to distinguish between certain colours.
The condition is often inherited. Other causes include certain eye diseases and medication. More men than women are affected.
If such a carrier woman with normal vision (heterozygous for colour blindness) marries a normal man (XY), the following progeny may be expected in the generation: among the daughters, 50% is normal and 50% are carriers for the diseases; among sons, 50% are colour blind and 50% are with normal vision.