Short Answer TypeGive four anatomical differences between a dicot and monocot root.
DICOT ROOT
An inconspicuous pith or may be absent as well.
Mostly the number of xylem bundles are 4–6. So tetra or hexaxylic condition.
Pericycle (a thin parenchymatous circular layer inner to the endodermis) gives rise to lateral roots and secondary meristem (cambium & phellogen).
Cambium appears as a secondary meristem.
Secondary growth is seen cutting the secondary xylem towards the inner side and secondary phloem towards the outer side.
E.g. Root ot wheat.
MONOCOT ROOT
A very well developed parenchymatous central pith is present
Xylem shows polyarch condition. Exception= Allium cepa (onion).
Pericycle forms only lateral roots but no secondary meristem.
No cambium is present between xylem and phloem.
E.g. Zea mays
Both dicot and monocot roots have radial & exarch xylem.
Write the names of the following :
(a) A 15 mya primate that was ape-like
(b) A 2 mya primate that lives in East African grasslands
With the help of an algebraic equation, how did Hardy-Weinberg explain that in a given population the frequency of occurrence of alleles of a gene is supposed to remain the same through generations?
Select and write analogous structures from the list given below:
(i) Wings of butterfly and birds
(ii) Vertebrate hearts
(ii) Tendrils of bougainvillaea and Cucurbita
(iv) Tubers of sweet potato and potato
Multiple Choice QuestionsConvergent Evolution' is shown by
homologous organs
analogous organs
vestigial organs
all of the above
Which of the following statements is correct
Lion and leopard show convergent evolution.
Cryptic camouflage is seen in Biston betularia
Natural selection is responsible for extinction of dinosaurs.
Homo habilis and Homo erectus are closely related.
Analogous structures are a result of
convergent evolution
shared ancestry
stabilising selection
stabilising selection
Switch
