Which of the following will occasionally produced a duplicate gene

Which of the following is a possible reason for sleep? a) growth b)digestive c)speed d)intelligence

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

The table below shows the number of foot bones in some horse fossils. horse fossil recordhorse fossil number of foot bonesp 19q 17r 24s 13ancient horses had more bones in their foot then present-day horses. the present-day horse has 11 foot bones. what is the correct order of evolution of the horse starting from the youngest fossil? a. q p r s b. s r p q c. s q p r d. r p q s