Karen and steve each have a sibling with sickle-cell disease. neither karen nor steve nor any of their parents have the dis- ease, and none of them have been tested to see if they have the sickle-cell trait. based on this incomplete information, calculate the probability that if this couple has a child, the child will have sickle-cell disease.

According to the theory of punctuated equilibrium, at what rate does speciation occur? species change depending on the rate of natural selection. after periods of stasis, new species evolve relatively rapidly. species change slowly and eventually form new species. some species change quickly and others change slowly to balance the overall rate.

Which of the following would be a body response when stepping outside without a coat on a snowy day? a. senaceous glands. secrete more senum b. more liquid is transported by the body to the skin fir insulation c. blood vessels in the skin narrow and contract d. blood vessels in the skin expand

20 point pls brianliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?