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TLS Online TPP Program

#Question id: 2624

What is negative regulation of lac operon

#Unit 2. Cellular Organization

  1. lactose+ & glucose +

  2. lactose- & glucose -

  3. in both conditions lactose has to be present

  4. in both conditions glucose has to be absent

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TLS Online TPP Program

#Question id: 5646

#Unit 5. Developmental Biology

In order to test how sea urchin sperm bind to eggs, scientists isolated the egg receptor protein that binds to the sperm acrosomal protein called bindin. Plastic beads were coated with egg receptor for bindin (ERB1) from eggs of the sea urchin Strongylocentrotus purpuratus, and then the beads mixed with sperm from S. purpuratus or from the related species, S. franciscanus. The researchers counted how many sperm were bound to each bead. The results are shown in the graph below. Treatments:

A: S. purpuratus sperm mixed with S. purpuratus ERB1 beads

B: S. purpuratus sperm mixed with beads containing no ERB1 protein

C: S. franciscanus sperm mixed with S. purpuratus ERB1 beads

D: S. franciscanus sperm mixed with beads containing no ERB1 protein

 Based on the description of the experiment, which of the treatments would be considered a "control" treatment for S. purpuratus sperm binding?
TLS Online TPP Program

#Question id: 5035

#Unit 5. Developmental Biology

 A fertilized egg is called a:
TLS Online TPP Program

#Question id: 11676

#Unit 7. System Physiology – Animal

In humans, the transport epithelial cells in the ascending loop of Henle:
TLS Online TPP Program

#Question id: 12721

#Unit 6. System Physiology – Plant

There are the five groups of late embryogenesis abundant (LEA) proteins found in plants

Match the following groups of LEA protein with its functional information;

 Group (family name)

                           Functional information

 

I) Group 1

   (D-19 family)

 

 

a) It is an abundant protein in cotton embryos, Each putative dimer of this group may bind as many as ten inorganic phosphates and their counterions

 

 

II) Group 2

    (D-11 family)

 

b) Possibly functions in ion sequestration to protect cytosolic metabolism When LE25 is expressed in yeast, it confers salt and freezing tolerance

 

 

III) Group 3

     (D-7 family)

 

c) In tomato, a gene encoding a similar protein is expressed in response to nematode feeding

 

 

IV) Group 4

    (D-95 family)

 

d) Contains more water of hydration than typical globular proteins Overexpression confers water deficit tolerance on yeast cells

 

 

V) Group 5

    (D-113 family)

 

e) Often localized to the cytoplasm or nucleus More acidic members of the family are associated with the plasma membrane May act to stabilize macromolecules at low water potential

 

TLS Online TPP Program

#Question id: 28044

#Unit 1. Molecules and their Interaction Relevant to Biology

Which one of the following is INCORRECT about protein structures?