#Question id: 28584
#Unit 2. Cellular Organization
Some given R factor which are responsible for beginning of the cell cycle in yeast cells?
#Question id: 11419
#Unit 10. Ecological Principles
There are more species in tropical areas than in places more distant from the equator. This is probably a result of
a) more predators and parasites
b) more dispersed annual solar radiation compared to the poles
c) more frequent ecological disturbances over a longer time span
d) a longer time frame without disturbances for evolution and speciation
#Question id: 7219
#Unit 5. Developmental Biology
Following statements are regarding to the role of the Disheveled and β-catenin proteins in specifying the cells of the sea urchin embryo.
A. During normal development, β-catenin accumulates predominantly in the micromeres and somewhat less in the veg2 tier cells.
B. In embryos treated with lithium chloride, β-catenin accumulates in the nuclei of all blastula cells and the cells of the animal pole become specified as ectoderm.
C. When β-catenin is prevented from entering the nuclei (i.e., it remains in the cytoplasm), the vegetal cell fates are not specified, and the entire embryo develops as a ciliated ectodermal ball.
D. When β-catenin is prevented from entering the nuclei (i.e., it remains in the cytoplasm), the vegetal cell fates are specified, and the entire embryo specified as endoderm and mesoderm .
Which of the following statements are true?
#Question id: 18940
#Unit 13. Methods in Biology
#Question id: 10813
#Unit 6. System Physiology – Plant
A living cytoplasmic connection penetrate the walls between sieve tube elements and their companion cells; which are often complex and branched on the companion cell side, known as