HAT (hypoxanthine, aminopterin and thymidine) is used for selecting the hybridomas based on the following<br>I. Only hybridoma will grow since it inherited the HGPRT genes from B-cells and can synthesize DNA from hypoxanthine.<br>II. Myeloma cells will not grow in cultures since de novo synthesis is blocked by aminopterin and due to the lack of HGPRT enzyme.

The primitive translation vectors of the body centred cubic lattice are $$\overrightarrow {\bf{a}} = \frac{a}{2}\left( {{\bf{\hat x}} + {\bf{\hat y}} - {\bf{\hat z}}} \right),\,\overrightarrow {\bf{b}} = \frac{a}{2}\left( { - {\bf{\hat x}} + {\bf{\hat y}} + {\bf{\hat z}}} \right)$$ and $$\overrightarrow {\bf{c}} = \frac{a}{2}\left( {{\bf{\hat x}} - {\bf{\hat y}} + {\bf{\hat z}}} \right)$$ . The primitive translation vectors $$\overrightarrow {\bf{A}} ,\,\overrightarrow {\bf{B}} $$ and $$\overrightarrow {\bf{C}} $$ of the reciprocal lattice are

A

$$\overrightarrow {\bf{A}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} - {\bf{\hat y}}} \right);\,\overrightarrow {\bf{B}} = \frac{{2\pi }}{a}\left( {{\bf{\hat y}} + {\bf{\hat z}}} \right);\,\overrightarrow {\bf{C}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} + {\bf{\hat z}}} \right)$$

B

$$\overrightarrow {\bf{A}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} - {\bf{\hat y}}} \right);\,\overrightarrow {\bf{B}} = \frac{{2\pi }}{a}\left( {{\bf{\hat y}} - {\bf{\hat z}}} \right);\,\overrightarrow {\bf{C}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} + {\bf{\hat z}}} \right)$$

C

$$\overrightarrow {\bf{A}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} + {\bf{\hat y}}} \right);\,\overrightarrow {\bf{B}} = \frac{{2\pi }}{a}\left( {{\bf{\hat y}} + {\bf{\hat z}}} \right);\,\overrightarrow {\bf{C}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} - {\bf{\hat z}}} \right)$$

D

$$\overrightarrow {\bf{A}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} + {\bf{\hat y}}} \right);\,\overrightarrow {\bf{B}} = \frac{{2\pi }}{a}\left( {{\bf{\hat y}} + {\bf{\hat z}}} \right);\,\overrightarrow {\bf{C}} = \frac{{2\pi }}{a}\left( {{\bf{\hat x}} + {\bf{\hat z}}} \right)$$

Lesch-Nyhan syndrome is caused by the deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Cells deficient in HGPRT die in a medium containing which of the following?

A

Hypoxanthine and thymidine

B

Thymidine

C

Aminopterin and thymidine

D

Hypoxanthine, thymidine and aminopterin (HAT medium)

If the resultant of $\vec{A}=6\hat{A}$ and $\vec{B}=8\hat{B}$ is $\vec{R}=10\hat{R}$ where $\hat{A},\hat{B}$ and $\hat{R}$ are the unit vectors along $\vec{A},\vec{B}$ and $\vec{R}$, then the value of $\vec{A}\cdot \vec{B}$ will be

A

50 units

B

100 units

C

0

D

None

What do you add to Myeloma cells to receive HGPRT- myeloma cells?

A

8 – Azaguanine

B

Azaguanine

C

Nitrogen flush

D

Carbon dioxide flush

Rima is traveling in her car at the speed of 60 km/hr. She drops her hat and didn’t recognize it for 10 minutes, during this time the hat travels due to air drag. As soon as she recognizes this she turns her car around and drive 50% faster to get her favourite hat, so that she could get her hat after 15 minutes after the fall. Find the average speed of the hat with which it travelled till it was caught.

A

20 km/hr

B

10 km/hr

C

30 km/hr

D

40 km/hr

$${\bf{\hat A}}$$ and $${\bf{\hat B}}$$ represent two physical characteristics of a quantum system. If $${\bf{\hat A}}$$ is Hermitian, then for the product $${\bf{\hat A\hat B}}$$ to be Hermitian, it is sufficient that

A

$${\bf{\hat B}}$$ is Hermitian

B

$${\bf{\hat B}}$$ is anti-Hermitian

C

$${\bf{\hat B}}$$ is Hermitian and $${\bf{\hat A}}$$ and $${\bf{\hat B}}$$ commute

D

$${\bf{\hat B}}$$ is Hermitian and $${\bf{\hat A}}$$ and $${\bf{\hat B}}$$ anti-commute

Given below is a word, followed by three sentences which consist of that word. Identify the sentence(s) which best express(es) the meaning of the word. Choose option 5 ‘None of the above’ if the word is not suitable in any of the sentences. BLOCKED A. The door blocked and Jo walked in. B. The road was blocked by fallen logs. C. A flock of sheep blocked our entry to the village.

A

Only A

B

Both B and C

C

Both A and C

D

Only B

E

None of the above

Consider the following statements regarding DNA replication and choose the correct answer:
1. The very first requirement of DNA synthesis is the presence of a template or plan along which the new strand is to be constructed
2. The second requirement is of a DNA-dependent-DNA polymerase or simply DNA polymerase enzyme
3. A DNA Pol cannot join two free nucleotides; one of them must be anchored by hydrogen bonds to a DNA strand
4. Replication takes place bidirectionally

A

1, 2, 3 and 4 are true

B

Only 2 and 4 are true

C

Oniy 2, 3 and 4 are true

D

Only 1 and 2 are true

Which of the following statement(s) is/are CORRECT for antigen activated effector T cells?
P. CD4+ cells make contact with macrophages and stimulate their microbicidal activity.
Q. CD4+ cells make contact with B cells and stimulate them to differentiate into plasma cells.
R. CD8+ cells make contact with B cells and stimulate them to differentiate into plasma cells.
S. CD8+ cells make contact with virus infected cells and kill them.

A

Q only

B

Q and S only

C

P, Q and S only

D

P, Q, R and S

Which of the following statements are correct regarding common differences between plant and animal cells?
1. Plant cells have cellulose cell wall, while animal cells lack it.
2. Plant cells lack plasma membrane, while animal cells have it.
3. Mature plant cell have a large vacuole, while animal cells have numerous small vacuoles.

A

1 and 2

B

2 and 3

C

1 and 3

D

1, 2 and 3

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