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TLS Online TPP Program

#Question id: 2228

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this fact most probably mean?

#Unit 2. Cellular Organization

  1. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

  2. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.

  3. Cells of each domain evolved proton pumps independently when oceans became more acidic.

  4. Proton pumps are necessary to all cell membranes.

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TLS Online TPP Program

#Question id: 28774

#Unit 2. Cellular Organization

Mutation in a structural gene that codes for the lysosomal hydrolase that causes disease, which is?
TLS Online TPP Program

#Question id: 28871

#Unit 4. Cell Communication and Cell Signaling

Wnts are___
TLS Online TPP Program

#Question id: 10362

#Unit 6. System Physiology – Plant

Bacteria can convert atmospheric nitrogen into ammonia, Several form symbiotic associations with higher plants is given below;

               HOST PLANT                                                                          N-FIXING SYMBIONTS

A) Gunnera                                                                            i) Frankia

      B) Azolla                                                                                ii) Acetobacter

C) Leguminous                                                                     iii) Azospirillum

             D) Actinorhizal                                                                      iv) Nostoc

             E) Sugarcane                                                                         v) Anabaena

             F) Miscanthus                                                                       vi) Sinorhizobium


Which of the following combination with the host plants and n-fixing symbionts is CORRECT?
TLS Online TPP Program

#Question id: 15150

#Unit 8. Inheritance Biology

In this problem we will explore some of the many ways that mutations in two different genes can interact to produce different Mendelian ratios. Consider a hypothetical insect species that has red eyes. Imagine mutations in two different unlinked genes that can, in certain combinations, block the formation of red eye pigment yielding mutants with white eyes. In principle, there are two different possible arrangements for two biochemical steps responsible for the formation of red eye pigment. The two genes might act in series such that a mutation in either gene would block the formation of red pigment. Alternatively, the two genes could act in parallel such that mutations in both genes would be required to block the formation of red pigment.
Further complexity arises from the possibility that mutations in either gene that lead to a block in enzymatic activity could be either dominant or recessive. If the crosses is made between a wild type insect with red eyes and a true breeding white eyed strain with mutations in both genes. Such considerations yield the Pathways in series with recessive mutations in both genes, the F1 progeny shows will have red eye, what is the expected phenotypic ratio of red to white eyed insects in the F2.
TLS Online TPP Program

#Question id: 33341

#Unit 2. Cellular Organization

The shape-determining protein crescentin in Caulobacter is related to the: