Biology today

11. Growth in numbers is maximum in the zone of
    (a) cell maturation (b) cell division
    (c) cell elongation (d) all of these.


12. Vascular tissues in flowering plants develop from
    (a) periblem (b) dermatogen
    (c) phellogen (d) plerome.


13. Anatomically fairly old dicotyledonous root is distinguished
    from the dicotyledonous stem by
    (a) absence of secondary phloem
    (b) presence of cortex
    (c) position of protoxylem
    (d) absence of secondary xylem.


14. Youngest layer of secondary xylem in wood of dicot plants
    is located between
    (a) pith and primary xylem
    (b) just outside vascular cambium
    (c) just inside vascular cambium
    (d) just inside cork cambium.


15. Between the bark and the wood in a woody stem, there
    is a layer of meristem called
    (a) cork cambium
    (b) apical meristem
    (c) vascular cambium
    (d) the zone of cell division.


16. Intercalary meristem occurs at the
    (a) bases of internodes of monocot plants
    (b) buds of the axillary leaves
    (c) apex of dicot stem
    (d) between the phloem and xylem.


17. Which one of the following is not correct?
    (a) Early wood is characterised by large number of xylary
    elements.
    (b) Early wood is characterised by vessels with wider
    cavities.
    (c) Late wood is characterised by large number of xylary
    elements.
    (d) Late wood is characterised by vessels with narrower
    cavities.


18. Refer to the given figure showing primary meristems and
    select the incorrect option for L, M and N.
    L

M

N

(a) Derivatives of the meristem ‘L’ produce the primary

plant body.

(b) Meristem ‘M’ is ususally present at the bases of

leaves and above or below the nodes.

(c) Meristem ‘L’ contributes towards primary growth and

meristem ‘N’ contributes towards secondary growth.

(d) Intrafascicular cambium is an example of ‘L’ type of

meristem.

19. Which of the following is correct with regard to histogen theory
    of Hanstein?
    (a) Dermatogen forms epidermis
    (b) Periblem forms vascular tissues
    (c) Plerome forms cortex
    (d) Calyptrogen forms endodermis


20. During secondary growth in dicot stems generally the periderm
    produces
    (a) phelloderm towards the periphery and cork towards
    the centre
    (b) phellem towards the periphery and phelloderm
    towards the centre
    (c) xylem towards the periphery and phloem towards the
    centre
    (d) none of these.

ANSWER KEY

1. (c) 2. (d) 3. (b) 4. (d) 5. (a)


2. (c) 7. (a) 8. (b) 9. (b) 10. (b)


3. (b) 12. (d) 13. (c) 14. (c) 15. (c)


4. (a) 17. (c) 18. (d) 19. (a) 20. (b)
   

h : Hexokinase

p : Phosphohexose isomerase

p : Phosphofructo kinase

a : Aldolase

t : Triose phosphate

g : Glyceraldehyde phosphate dehydrogenase

p : Phosphoglycerate kinase

p : Phosphoglycerate mutase

e : Enolase

p : Pyruvate kinase

To easily remember ten enzymes involved stepwise in glycolysis,

the mnemonic “High Profile People Act Too Glamourous, Picture

Posing Every Place” can be used as follows: