Following statements are regarding to double fertilization in angiosperms.

A. One sperm cell fuses with the egg cell to produce the zygote that will develop into the new embryonic plant.

B. The second sperm cell fuses with the usually binucleate central cell, giving rise to the

endosperm, the tissue that nourishes the developing embryo. This second event is not “true” fertilization in the sense of male and female gametes undergoing fusion.

C. The second sperm cell fuses with the usually binucleate central cell, giving rise to the

endosperm, the tissue that nourishes the developing embryo. This second event is “true” fertilization in the sense of male and female gametes undergoing fusion.

D. During fertilization in angiosperm, when the sperm cells are released, the egg undergoes a flux of Ca2+. Then, chemicals released from the egg appear to make the sperm competent for cell fusion.

Which of the following statements are true?

TLS Online TPP Program

#Question id: 12705

#XL - R Botany

In Neurospora crasssa, the mutant exhibit poky phenotype, when a female of  poky strain is crossed with a normal strain acting as a male , all progeny individuals shows poky phenotype . however, the reciprocal cross resulted in all normal progeny. These results can be explained on the basis of 

TLS Online TPP Program

#Question id: 12718

#XL - R Botany

primary disruptions could be signaling the plant that a change in environmental conditions has occurred and that it’s time to respond by altering existing pathways or by activating stress-response pathways. At least five different types of stress-sensing mechanisms can be distinguished:

COLUMN I	COLUMN II
A) Physical sensing	i) usually results from the detection of by-products that accumulate in cells due to the uncoupling of enzymatic or electron transfer reactions, such as the accumulation of ROS during stress caused by too much light.
B) Biophysical sensing	ii) often involves the presence of specialized proteins that have evolved to sense a particular stress; for example, calcium channels that can sense changes in temperature and alter Ca2+ homeostasis.
C) Metabolic sensing	iii) refers to modifications of DNA or RNA structure that do not alter genetic sequences, such as the changes in chromatin that occur during temperature stress.
D) Biochemical sensing	iv) refers to the mechanical effects of stress on the plant or cell structure, for example, the contraction of the plasma membrane from the cell wall during drought stress.
E) Epigenetic sensing	v) might involve changes in protein structure or enzymatic activity, such as the inhibition of different enzymes during heat stress.

 

  

Match the correct sequence sensing mechanism during in stress;

TLS Online TPP Program

#Question id: 12719

#XL - R Botany

Which of the following is a key enzyme in the proline biosynthetic pathway?

TLS Online TPP Program

#Question id: 12722

#XL - R Botany

Eleven amino-acid consensus sequence motif TAQAAKEKAXE is repeated in the protein,  is the structural characteristics of which type of group of LEA protein?

TLS Online TPP Program

#Question id: 12725

#XL - S Microbiology

Match the following

DNA form	Helix Direction	Number of bases per helix turn
1. B	a. Left Handed	i. 10
2.  A	b. Right Handed	ii. 12
3.  C	c. Left Handed	iii. 14
4. Z	d. Right Handed	iv. 9

TLS Online TPP Program

#Question id: 12726

#XL - S Microbiology

Name the forms of DNA which have been derived under laboratory conditions.