What causes a green plant exposed to the light on only one side, to bend toward the source of light as it grows?
Green plants need light to perform photosynthesis.
Green plants seek light because they are phototropic
Light stimulates plant cells on the lighted side to grow faster
Light stimulates plant cells on the lighted side to grow faster
In a ring girdled plant
the shoot dies first
the root dies first
the shoot and root die together
the shoot and root die together
Which one gives the most valid and recent explanation for stomatal movements?
Transpiration
Potassium influx and efflux
Starch hydrolysis
Starch hydrolysis
The hilum is a scar on the
seed, where funicle was attached
fruit, where it was attached to pedicel
fruit, where style was present
fruit, where style was present
Transmission tissue is characteristic feature of
hollow style
solid style
dry stigma
dry stigma
Which one of the following is a wrong statement regarding mutations?
Deletion and insertion of base pairs cause frame-sheft mutations
Cancer cells commonly show chromosomal aberrations
UV and Gamma rays are mutagens
UV and Gamma rays are mutagens
A test cross is carried out to
determine the genotype of a plant at F2
predict whether two traits are linked
assess the number of alleles of a gene
assess the number of alleles of a gene
Read the following four statement.
1. In transcription, adenosine pairs with uracil
2. Regulation of lac operon by repressor is referred to as positive regulation.
3. The human genome has approximately 50,000 genes.
4. Haemophilia is sex-linked recessive disease.
How many of the above statements are right?
Two
Three
Four
Four
What is the function of germ pore?
Emergence of radicale
Absorption of water for seed germination
Initiation of pollen tube
Initiation of pollen tube
C.
Initiation of pollen tube
The pollen grain has two layers - outer exine and inner intine. Exine is made up of highly resistant sporopollenin while intine is pectocellulosic. At certain places exine is thin or absent called germpore or germinal furrow. After reaching on stigma the pollen grain absorbs water and nutrients from the stigmatic secretion through its germ pore. The tube or pollen grain through one of the germ pores or germinal furrows to form a pollen tube.
Which one of the following statements is wrong?
When pollen is shed at two-celled stage, double fertilization does not take place
Vegetative cell is larger than generative cell
Pollen grains in some plants remain viable for months
Pollen grains in some plants remain viable for months