The presence of cyanobacteria ____ in rock dating to 2.5 billion years ago is direct evidence of the first water-splitting
photosynthesizers.
a. microfossils
b. biosignatures
c. stromatolites
d. cytoskeletons
e. endosymbiont
ANSWER: b
You might also like to view...
In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?
A) A = G B) A + G = C + T C) A + T = G + T D) A = C E) G = T
The earliest fish are represented today by:
a. hagfish. b. lamprey. c. sharks. d. both a and b. e. both b and c.
Analysis of the genome and transcriptome of the highly radiation resistant bacterium Deinococcus radiodurans has revealed all of the following EXCEPT ________.
A. it has more DNA repair genes than E. coli B. genes whose products are involved in cell wall metabolism and cellular transport are dramatically up-regulated after irradiation C. its genome consists of two circular chromosomes and two plasmids D. genes whose products are involved in DNA replication and recombination are dramatically up-regulated after irradiation
Which statement about a monohybrid test cross is not true?
a. It tests whether an individual of unknown genotype is homozygous or heterozygous. b. The test individual is crossed with a homozygous recessive individual. c. If the test individual is heterozygous, the progeny will have a 1:1 phenotypic ratio. d. If the test individual is homozygous, the progeny will have a 3:1 phenotypic ratio. e. Test cross results are consistent with Mendel's model of inheritance