Many of the carriers of Sucrose–H+ symporters in the phloem play various role in transport, most of the transporters are found in source, path, and sink tissues. Some carriers are characterized such as;

a) SUT1, has high-affinity / low-capacity transporter found in the minor veins of source tissues, appears to be important in phloem loading.

b) Important role of SUT1 in phloem loading appears to be complemented by SUT4, which is low-affinity/high-capacity carrier

c) SUT2, appears to function as a sucrose sensor. This is indicated by findings showing that SUT2 is more highly expressed in sink and path tissues than in source leaves.

d) The major sucrose transporters in phloem loading into the companion cells and final uptake into companion cells appears to be the function of SUT4

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 12834

#Unit 2. Cellular Organization

How Aurora B and the spindle assembly checkpoint pathway collaborate during every cell cycle to accurately attach every single pair of sister chromatids to the mitotic spindle in the correct, bioriented manner?

TLS Online TPP Program

#Question id: 12486

#Unit 2. Cellular Organization

Which of the following process occur in prometaphase?

TLS Online TPP Program

#Question id: 12485

#Unit 2. Cellular Organization

Following statements are regarding to the centrosome cycle of an animal cell.

A. During G1, the daughter procentrioles continue to elongate.

B. During S phase, daughter procentrioles form adjacent to maternal centrioles so that two pairs of centrioles become visible within the centrosome. 

C. During G2 phase, the centrosome contains a single pair of centrioles.

D. At the beginning of mitosis, the centrosome splits, with each pair of centrioles becoming part of its own centrosome. As they separate, the centrosomes organize the microtubule fibres that make up the mitotic spindle.

Which of the following option is correct? 

TLS Online TPP Program

#Question id: 12484

#Unit 2. Cellular Organization

Match the following.

Column I	Column II
A. APC/CCdc20	i . responsible for ubiquitinating proteins, such as mitotic cyclins
B. APC/CCdh1	ii. responsible for destroying proteins, such as securin
	iii. promotes the metaphase–anaphase transition
	iv. Promotes exit from mitosis

Which of the following is correct?

TLS Online TPP Program

#Question id: 12483

#Unit 2. Cellular Organization

ATM and ATR are protein kinases that become activated following specific types of DNA damage. 

A. ATM becomes activated in response to double‐strand breaks, which are detected by the MRN protein complex. 

B. ATR becomes activated by protein‐coated ssDNA that forms when replication forks become stalled or the DNA is being repaired after various types of damage.

C. ATR phosphorylates and activates the checkpoint kinase Chk2, which phosphorylates p53. D. ATM phosphorylates and activates the checkpoint kinase Chk1, which phosphorylates and inactivates the phosphatase Cdc25.

Which of the following combination is incorrect?

TLS Online TPP Program

#Question id: 12482

#Unit 2. Cellular Organization

The Rb protein has been called the “master brake” of the cell cycle. How the Rb protein acts as a cell cycle brake?