Sexual dimorphism, as seen in the crayfish, is
a. the presence of male and female individuals.
b. the production of eggs and sperm by the same individual.
c. another term for copulation.
d. the presence of observable differences between males and females.
d
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In plants, genes E, F, and G are on one chromosome arm. Alternate dominant and recessive alleles of all three genes determine visible traits: E = normal leaf number, e = extra leaves, F = normal stems, f = furry stems, G = normal flower size, g = gigantic flowers. A plant that is heterozygous for an inversion involving all three genes is crossed to a plant with extra leaves, furry stems, and gigantic flowers. The arrangement of alleles is shown in the diagram. If you look at thousands of offspring of this cross, what phenotypes do you expect to see?(Select all that apply.)
A) Most, but not all, offspring will be normal for all three traits or have extra leaves, furry stems, and gigantic flowers.
B) Due to double crossovers between E and F and F and G, a very small number of offspring will have only furry stems, or only extra leaves and gigantic flowers.
C) Half of the offspring will be normal for all three traits and half will have extra leaves, furry stems, and gigantic flowers.
D) Due to crossovers between E and F in parent 1, a small number of offspring will have only extra leaves, or only furry stems and gigantic flower size.
E) Due to crossovers between F and G, a small number of offspring will have only extra leaves and furry stems, or only gigantic flower size.
Floods are worse after levees are built and wetlands are drained because
A. water moves into rivers more quickly. B. rainfall becomes more intense per unit area. C. the total volume of water increases. D. people complain more about damage. E. All of these are reasons floods are worse after levees are built and wetlands are drained.
The text indicates that the digestive tract in vertebrates is ventral to (beneath) the backbone. Yet our digestive tract is in front of our backbone, which is still considered ventral. Why is this an appropriate statement?
A) Terms like ventral that describe spatial relationships between structures are based on a common body plan of a creature who walks on four legs and in that case the digestive track would be ventral to the backbone. B) Humans have entirely different organ arrangements than any other vertebrates so words like ventral take on entirely different meanings. C) It is wrong to say that our digestive track is ventral to the backbone.
Common commercial benefits of microorganisms include synthesis of
A) riboflavin. B) acetone. C) insulin. D) aspirin. E) riboflavin, acetone and insulin.