Which of the following molecular hydrides acts as a Lewis acid?

1. $N{H}_3$

2. $H_{2}O$

3. $B_2{H}_6$

4. $C{H}_4$

The tendency of BF₃, BCl₃ and BBr₃ to behave as Lewis acid decreases in the sequence:

1. $BC{l}_3>B{F}_3>BB{r}_3$

2. $BB{r}_3>BC{l}_3>B{F}_3$

3. $BB{r}_3>B{F}_3>BC{l}_3$

4. $B{F}_3>BC{l}_3>BB{r}_3$

In vitro fertilization is a technique that involves the transfer of which one of the following into the Fallopian tube?

1. Embryo only, upto 8 cell stage

2. Either zygote or early embryo up to 8 cell stage

3. Embryo of 32 cell stage

4. Zygote only

Which one of the following structures between two adjacent cells is an effective transport pathway?

1. Plasmodesmata

2. Plastoquinones

3. Endoplasmic reticulum

4. Plasmalemma

Single-celled eukaryotes are included in:

1. Protista

2. Fungi

3. Archaea

4. Monera

The genetically-modified (GM) brinjal in India has been developed for:

1. insect-resistance

2. enhancing self-life

3. enhancing mineral content

4. drought-resistance

In unilocular ovary with a single ovule, the placentation is:

1. marginal

2. basal

3. free central

4. axile

An element playing important role in nitrogen fixation is:

1. molybdenum

2. copper

3. manganese

4. zinc

Sertoli cells are found in:

Which one of the following cannot be explained on the basis of Mendel's Law of Dominance?