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TLS Online TPP Program

#Question id: 7118

At the molecular and cellular level, how does morphogenesis differ from establishment of embryonic axes and the specification of cellular identity?

#Unit 5. Developmental Biology
  1. The formation of embryonic axes and the specification of cell fates rely heavily on gene expression patterns, whereas morphogenesis relies primarily on cell-cell signalling.
  2. The specification of pattern and fate has been presented as being completely under maternal control, whereas morphogenesis concerned with zygotic control over development.
  3. The formation of embryonic axes and the specification of cell fates rely heavily on cell-cell signaling events, and their influence over gene expression patterns, whereas morphogenesis relies primarily on cell-cell adhesion and cell motility.
  4. There is no fundamental difference in mechanism between patterning events such as axis formation and morphogenic events such as gastrulation.
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TLS Online TPP Program

#Question id: 14736

#Unit 2. Cellular Organization

In basal structure of flagella of gram positive bacteria?
1. L
2. P
3. S
4. M
Which combination is not found in above bacteria? Choose the option with both incorrect rings.
TLS Online TPP Program

#Question id: 14737

#Unit 2. Cellular Organization

Which structures are involved in formation of biofilms
TLS Online TPP Program

#Question id: 14738

#Unit 4. Cell Communication and Cell Signaling

Choose correct statements about Muscarinic receptors;
a. An acetylcholine analog, In activated condition, these receptors slow the rate of heart muscle contraction.
b .This type of receptor is coupled to a Gαi protein, and ligand binding leads to the opening of an associated K+ channel.
c .The subsequent influx of K+ ions from the cytosol causes an increase in the magnitude of the usual inside-negative potential across the plasma membrane that lasts for several seconds. 
TLS Online TPP Program

#Question id: 14739

#Unit 4. Cell Communication and Cell Signaling

In heart muscle, activation series of the muscarinic acetylcholine receptor its effector K+ channel via the Gβγ subunit of a Gi protein.
a. Binding of acetylcholine triggers activation of the Gαi subunit and its dissociation from the Gβγ subunit in the usual way. 
b. The released Gβγ subunit (rather than Gαi∙GTP) binds to and opens the associated effector protein, a K+ channel. 
b. The increase in K+ permeability hyperpolarizes the membrane, which reduces the frequency of heart muscle contraction. 
d. Activation is terminated when the GTP bound to Gαi is hydrolyzed (by a GAP enzyme that is an intrinsic part of the Gαi subunit) to GDP and Gαi∙GDP recombines with Gβγ.
TLS Online TPP Program

#Question id: 14740

#Unit 4. Cell Communication and Cell Signaling

Rod cells sense light with the aid of a light-sensitive GPCR known as rhodopsin; choose incorrect statements
a. Rhodopsin consists of the protein opsin, which has the usual seven–transmembrane segment GPCR structure, covalently linked to a light-absorbing pigment called retinal. 
b. Rhodopsin, found only in rod cells, is localized to the thousand or so flattened membrane disks that make up the inner segment of each of these rod-shaped cells.
c. A human rod cell contains about 4 × 107 molecules of rhodopsin. 
d. The heterotrimeric G protein coupled to rhodopsin, called transducin (Gt), contains a Gα unit referred to as Gαt; like rhodopsin, Gαt is found only in rod cells.
TLS Online TPP Program

#Question id: 14753

#Unit 6. System Physiology – Plant

German scientist Adolf Fick discovered that the rate of diffusion is directly proportional to the concentration gradient (∆cs /∆x)—that is, to the difference in concentration of substance s (∆cs ) between two points separated by the distance ∆x. According to Fick’s first law,