HELP PLEASE I LUV YALL A child is born with cystic fibrosis, an inherited recessive disorder. No one in the family (on either side) for several generations is known to carry the gene or have the disorder. How can this be explained?
a The genetic disorder formed from the mother's poor nutrition and prenatal care.
b There was a mutation in the DNA, either in one of the gametes or the fertilized egg.
c The child contracted the illness from another child when he was born.
d The child developed the disorder when he was born; it is a result of a birth defect.

Which of the four major uses is predicted to change the least by 2020?

This aquarium exhibits biotic and abiotic factors in an aquatic environment. one of the abiotic factors is

Sally and sue were investigating the topic of friction in science. they used a small car and a ramp as seen in the picture to test what they were learning. they knew that they slipped easily on waxed floors but not on carpet, so they decided to change the material on the surface of the ramp to see what happened. they planned to use glass, carpet, aluminum foil, and sandpaper and run the car down the ramp over each surface. what would be the best research question to guide the girls' experiment? a) does the amount of surface area affect the friction on the moving car? b) will the car travel fastest on the glass surface? c) how does the angle of the ramp affect the speed of the car? d)do rougher surfaces tend to create more friction than smooth surfaces?