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TLS Online TPP Program

#Question id: 863

Ubiquitinated proteins are proteolytically degraded in an ATP-dependent process mediated by a large (∼2500 kD, 26S) multiprotein complex named the 26S proteasome;

#Unit 1. Molecules and their Interaction Relevant to Biology

  1. A hollow cylindrical core, known as the 20S proteasome, which is covered at one or both ends by a 19S cap.

  2. The yeast 20S proteasome, which is closely similar to other eukaryotic 20S proteasomes, is composed of Ten different types of α-like subunits.

  3. The yeast 20S proteasome, which is closely similar to other eukaryotic 20S proteasomes, is composed of seven different types of α-like subunits and seven different types of β-like subunits.

  4. The α-type subunits and the β-type subunits are structurally similar, only three of the β-type subunits have proteolytic activity.

    Choose any one incorrect option.

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TLS Online TPP Program

#Question id: 5681

#Unit 5. Developmental Biology

What is the arrangement of microtubules in sperm flagellum?
TLS Online TPP Program

#Question id: 5680

#Unit 5. Developmental Biology

In vitro model of species-specific binding shows in figure. Add the bindin particles to a plastic well containing a suspension of eggs. After 2–5 minutes of gentle shaking, the wells were photographed.

 According to this figure, which of the following conclusion correctly define the phenomenon of species specificity?
TLS Online TPP Program

#Question id: 5679

#Unit 5. Developmental Biology

Following statements regarding to the molecular processes of capacitation.

A. The sperm cell membrane is altered by the removal of albumin by cholesterol in the female reproductive tract.

B. Particular proteins or carbohydrates on the sperm surface are lost during decapacitation.

C. The membrane potential of the sperm cell becomes more positive as potassium ions leave the sperm. This change in membrane potential may allow calcium channels to be opened and permit calcium to enter the sperm.

D. Calcium and bicarbonate ions are critical in activating cAMP production and in facilitating the membrane fusion events of the acrosome reaction.

E. As a result of cAMP formation, protein phosphorylation occurs. Once they are phosphorylated, some proteins migrate to the surface of the sperm head. One of these proteins is izumo, which is critical in sperm-egg fusion.

which one of the following combinations is correct?
TLS Online TPP Program

#Question id: 5678

#Unit 5. Developmental Biology

Following process and their mechanism during fertilization in mammals.

 a. Rheotaxis

i.A sensing mechanism in which, the oocyte and its accompanying

cumulus cells secrete molecules that attract capacitated

sperm toward the egg during the last stages of sperm migration

b.  Chemotaxis

ii.It is a transient event, and sperm are given a relatively brief window of competence during which they can successfully fertilize the egg.

c.  Capacitation

iii.it is the ability to sense temperature difference and preferentially swim from cooler to warmer sites is found only in capacitated sperm.

d. Thermotaxis

iv.Sperm receive long-distance directional cues from the flow of liquid from the oviduct to the uterus and they will migrate against the direction of the flow—using CatSper calcium channels to sense calcium influx and monitor the direction of the current
     

Which of the following option is correct?
TLS Online TPP Program

#Question id: 5677

#Unit 5. Developmental Biology

During acrosome reaction, after binding with the egg many sperm membrane proteins are activated. Which of the following membrane protein is not activated?
TLS Online TPP Program

#Question id: 5676

#Unit 5. Developmental Biology

The importance of dynein can be seen in individuals with a genetic syndrome known as the Kartagener triad. which of the following statement is correct?