You have isolated two mutations in the Lac operon that cause constitutive expression of Lac genes. You designate these mutants Lac1– and Lac2–. Making use of an F' that carries the Lac operon with the LacY gene mutated, you construct strains that you test for both ß-galactosidase activity and Lac permease activity with results shown below.

     

Classify each mutation as dominant or recessive and as cis- or trans-acting, giving the experimental result that allows you to arrive at each conclusion. Finally, deduce what type of Lac mutation best fits the properties of Lac 1– and of Lac 2–.

#Question id: 29074

#Unit 10. Ecological Principles

Given below is a matrix of possible interactions beneficial. (+), harmful (-), Neutral (0) between species 1 and 2. The names of interactions, A, B, C, D and E respectively;

#Question id: 29075

#Unit 10. Ecological Principles

Identify the pollinators for the flowers with following pollination syndromes

I- Flowers evolved features such as blue purple yellow and various other except red

II- Flowers evolved features such as no fragrance because their pollinators has poor sense of smell

III- Flowers only white or light , reflective colors only with strong odori because their pollinators has good sense of smell

IV- flower has every colour including red colour with light floral scent and also providing landing place for nectar

#Question id: 29076

#Unit 10. Ecological Principles

Corals and the Dinoflagellates showing which type of mutualism

#Question id: 29077

#Unit 10. Ecological Principles

The relationship between acacia plants and the ants that live within their thorns is

#Question id: 29078

#Unit 10. Ecological Principles

A specific kind of parasitism proposes that  in which cuckoos or cowbirds repeatedly check their host’s nests and destroy all eggs if their owner is not present. If the parasite egg has been removed, they destroy the host’s nest and kill or injure the nestlings, this is an example of____

#Question id: 29079

#Unit 10. Ecological Principles

You observed the two species of barnacles, P. aurelia and P. caudatum, occupy upper and lower strata of intertidal rocks, respectively. Only when P. caudatum was removed by you from the lowers strata, P. aurelia could occupy both the upper and lower strata. From the choice given below what would be your inference from these observations.