Indicate whether each of the following descriptions better applies to egg-polarity genes (E), gap genes (G), pair-rule genes (P), or segment-polarity genes (S). Your answer would be a four-letter string composed of letters E, G, P, and S only, e.g. SSGG.
( ) Mutations in these genes show a maternal effect.
( ) Mutations in these genes leave the embryo with only half the number of normal segments.
( ) Mutations in these genes produce a normal number of segments but with part of each segment replaced by a mirror-image duplicate of other parts of the segment.
( ) Mutations in these genes can eliminate one or two groups of adjacent segments altogether.