Which one of the followings is correct for the trans membrane proteins in lipid bilayer?
They are absent in animal cells
They act as channel proteins
They are absent in plant cells
They are only externally located
B.
They act as channel proteins
Transmembrane proteins in lipid bilayer occur in many forms and are responsible for transferring specific solutes across cell membrane.
Channel proteins, from water - filled pores that extend across the lipid bilayer, when these pores are open, they allow specific solutes (usually inorganic ions of appropriate size and charge) to pass through them and there by cross the membrane.
Select correct combination of statements for lymph.
I. It helps to maintain fluid balance of the body.
II. It is contained in lymphatic vessels and lymphatic organs in mammals.
III. It is derived from tissue fluid.
IV. It contains less antibodies than plasma.
V. Flows in both directions.
VI. It helps to conserve proteins and remove bacteria.
I, II, III, V
II, III, IV, VI
I, IV, V, VI
III, IV, V, VI
Two membrane envelops is found in
mitochondria, Golgi apparatus and chloroplast
mitochondria, nucleus and chloroplast
nucleus, Golgi apparatus and endoplasmic reticulum
nucleus, ribosome and chloroplast
Which one of the following is correct for blooming of 'short day' plants?
The long dark period is not critical
It is affected by interruption of long dark period by brief exposure of light
It is not affected by interruption of long dark period by brief exposure of light
It is affected if the continuous light period is interrupted
A dicotyledonous plant forms crown gall when
Agrobacterium tumefaciens comes in contact with the plant
Agrobacterium rhizogenes comes in contact with the plant
a specific part of DNA from the Ti-plasmid gets integrated with the plant chromosome
a specific part of DNA from the Ri-plasmid gets integrated with the plant chromosome
Match the item in column I with those in column II and the choose the correct answer.
| Column I | Column II |
| A. Mitosis | 1. Occurs in diploid cells only |
| B. Meiosis | 2. Occurs in both haploid and diploid cells |
| 3. Daughter and parent cells have same chromosome numbers | |
| 4. Synapsis of homologous chromosomes. |
A- 1; B- 2
A- 2; B- 3
A- 3; B- 4
A- 4; B- 1
