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?

#Question id: 7273

#Unit 5. Developmental Biology

Hox9 and Hox10 paralogues specify the stylopod, Hox11 paralogues specify the zeugopod, and Hox12 and Hox13 paralogues specify the autopod. This scenario has been confirmed by numerous experiments.

Which of the following experiment correctly describe this scenario?

#Question id: 7272

#Unit 5. Developmental Biology

Few statements regarding the role of disheveled (dsh) and beta-catenin in the development of sea urchin.

A. beta-catenin accumulates predominantly in the macromeres and somewhat in veg2 tier cells.

B. At the fourth cleavage disheveled and β-catenin, both of which are found in the cytoplasm and are inherited by the micromeres.

C. Treating sea urchin embryos with lithium chloride allows β-catenin to accumulate in every cell and transforms presumptive ectoderm into endoderm.

D. When β-catenin is prevented from entering the nuclei (i.e., it remains in the cytoplasm), the vegetal cell fates are specified, and the entire embryo develops as a ciliated ectodermal ball.

Which one of the following options represents a combination of correct statement?

#Question id: 7271

#Unit 5. Developmental Biology

In drosophila, Head formation required higher Bicoid concentrations than thorax formation, because

#Question id: 7270

#Unit 5. Developmental Biology

According to this figure which of the following option is incorrect?

#Question id: 7269

#Unit 5. Developmental Biology

Following statements are regarding to gastrulation in chick embryo.

A. During gastrulation, future mesodermal and endodermal cells migrate from the epiblast through the primitive streak into the interior of the blastoderm.

B. An aggregation of cells, known as Hensen’s node, forms at the posterior end of the streak.

C. As the streak extends, cells of the epiblast move toward the primitive streak, through it, and then outward again underneath the surface to give rise internally to the mesoderm and endoderm, the latter displacing a lower layer of cells called the endoblast.

D. Cells that remain in the epiblast form the endoderm.

Which of the following statements are correct?

#Question id: 7268

#Unit 5. Developmental Biology

Match the columns and choose the correct option.