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, what will be the phenotype in F1 progeny?

#Question id: 11049

#Unit 6. System Physiology – Plant

Match the CORRECT combination of the phloem elements with its function.

            PHLOEM ELEMENTS                                                  FUNCTIONS

P) sieve tube elements                                    i) for protection and strengthening of the tissue

Q) sieve cells                                                  ii) store and release food molecules

R) companion cells                                        iii) food translocation in angiosperm

S) Phloem parenchyma cells                          iv) latex containing cells

T) Phloem fibers and sclereids                       v) help in flow of solute and show high, metabolic activity

U) laticifers                                                     vi) food translocation on gymnosperm

#Question id: 11050

#Unit 6. System Physiology – Plant

Three dimensional reconstructions of Arabidopsis sieve plates using a staining technique that can be used to image entire plant organs and Open sieve pores are visible as well as callose plug are also visible which technique used to analyze

#Question id: 11051

#Unit 10. Ecological Principles

Disadvantages of living in groups include

#Question id: 11052

#Unit 10. Ecological Principles

An example of territoriality is

#Question id: 11053

#Unit 10. Ecological Principles

The key difference between a territory and a home range is

#Question id: 11054

#Unit 10. Ecological Principles

In red grouse populations on the grasslands, many males do not acquire territories. Which of the following is least likely to be a valid hypothesis about these male grouse?