CBSE
Multiple Choice QuestionsWhich of the following is not true for inbreeding?
It causes inbreeding depression after a few generations
It always increases the productivity.
It is used to produce a pure line.
It leads to homozygosity
How many haploid nuclei are present in a mature pollen grain
One
Two
Three
Four
After doble fertilization, a mature ovule has
1 diploid and 1 haploid cell
1 diploid and 1 triploid cell
2 haploid and 1 triploid cell
1 haploid and 1 triploid cell
What is the characteristic of tapetum
It does not store food.
It is multi-nucleated.
It is multi-layered structure.
It nourishes the megaspore
Plants with inferior ovary usually bear
pseudocarps
berries
aggregate fruits
seedless fruits
Sporopollenin is a constituent of pollen exine. It can be degraded by the action of
enzymes
high temperature
strong acids
cannot be degraded
Assertion : Commelina shows cleistogamy.
Reason : This reduces chances of inbreeding.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
The pollen grains of rice and wheat lose their viability inminutes of their release
30
10
60
90
The given figure shows L.S of the seed of maize. What do A, B, C and D represent?
A : endosperm, B : scutellum, C : plumule, D : coleoptile
A : scutellum, B : pericarp, C : radicle, D : coleoptile
A : endosperm, B : scutellum, C : radicle, D : coleorrhiza
A : scutellum, B : pericarp, C : plumule, D : coleorrhiza
Cotton fibres mainly contains
cellulose
glycogen
protein
lipid
