Crossing over, or recombination, is thought to be evolutionarily advantageous because it continually shuffles genetic alleles into novel combinations. until recently, it was thought that y-linked genes might degenerate because they have no homologous genes on the x chromosome with which to recombine. however, when the y chromosome was sequenced, eight large regions were found to be internally homologous to each other, and quite a few of the 78 genes represent duplicates. how might this be beneficial?

Need will mark ! which features are created by groundwater erosion and deposition? check all that apply. a. stalagmitesb. sinkholesc. rillsd. stalactites e. gullies f. rivers

Part a - prefixes, roots, and suffixes match these prefixes, suffixes and roots to their meanings. phospho- angio- -uria -tropic -phag- a. the word root means blood or lymph vessels. b. the word root means urine. c. the word root means feeding or eating. d. the word root means phosphate or phosphorus. e. the word root means attracted specifically to the specified organ or tissue. part b – match these vocabulary terms to their meanings. gonadotropic polyuria angiotensin ii polyphagia phosphodiesterase upon the release of renin, is produced and stimulates vasoconstriction and the release of aldosterone. fsh and lh are examples of hormones, which target the ovaries or testes. an enzyme that degrades second messengers like camp or cgmp is . overproduction of urine, or , is a sign of diabetes mellitus. overeating, or , is a sign associated with diabetes mellitus.

Two male mice, which we will call male a and male b, are both phenotypically normal. male a was from a litter that contained half phenotypically normal mice and half dwarf mice. the mother of male a was known to be homozygous for the normal igf2 allele. male b was from a litter of eight mice that were all phenotypically normal. the parents of male b were a phenotypically normal male and a dwarf female. male a and male b were put into a cage with two female mice that we will call female a and female b. female a is a dwarf and female b is phenotypically normal. the parents of these two females were unknown, although it was known that they were from the same litter. the mice were allowed to mate with each other, and the following data were obtained: female a gave birth to three dwarf babies and four normal babies. female b gave birth to four normal babies and two dwarf babies. which male(s)mated with female a and female b? male a with both females male a with female b, and male b with female a male a with female a, and male b with female b could not be determined male b with both females