Kerala Plus One Answer Key 2025 Botany

FIRST YEAR HIGHER SECONDARY EXAMINATION MARCH 2025
PART 3-BOTAI.IY ANSWER KEY
CODE NO: FY-32 6 SCORE.3O
SIJB ANSWER KEY I VALUE POINTS SCORE TOT
Q.N AL
o Q.N SCO
o RE

I Chrysophytes / (a) I 1

2 Floridean starch 1 I

3 Reticulate venation I 1

4 Zygotene 1 I

5 Exponential phase /Log phase I I

6 Phycobiont refers to the algal component of the lichens. I 2
Mycobiont refers to the fungal component. I
OR
Algae contain chlorophyll and prepare food for fungi.
Whereas the fungus provides shelter to algae and absorbs
water and nutrients from the soil.

7 l.Chlamydomonas - 3/Algae U2

2. Cycas - 4/Gymnosperm U2
",
3. Selaginella- 2/ Pteridophyte
112
4. Sphagnum- 1/ Moss y2

8. I A. Subsidiary cell v2
B. Guard cell
U2
il. Stomatal aperture/Stomatal pore, Guard cells and the 2
surrounding subsidiary cells are the constituents of the stomatal
1
apparatus

9 A Conjoint closed /closed l2
1. Phloem U4
U4
2.Xylem
)
B Conjoint open/ open U2
3. Cambium U2

10 a Fluid mosaic model y2
b Protein / Lipids (Phospholipids/ cholesterol)/ carbohydrates (any u2+U2
two)
Transport of molecules across itlsimple diffusion 2
c /facilitated diffrrsion/active transporVcell
U2
growth/Osmosis/formation of inhacellular
junctions/secretior/endocytosis/cell division (any one))

l1 a Cristae v,
Cristae are infoldings of Mitochondria/ all other terms related
to parts of chloroplast. %
b Fimbriae. %
The fimbriae are small bristle like fibres sprouting out of the 2
cell of bacteria / helps bacteria for attachments/ all other terms Y,
related to parts of chromosome.

12. Ribulose l-5 bis phosphate/ Ribulose 1-5 biphosphate 1
/Ribulose bis phosphate
2
RuBp is the accepter of COz during the dark reaction of I
photosynthesis

l3 .a Photorespiration 1

b In this process neither synthesis of sugars /
No energy formation or ATP/ NADPH. 1 2
It results in release of CO2 with the utilization of ATP. ( any two
points)

14. a Acetyl CoA 1 2
b Pynrvic dehydrogenase /Pynrvate dehydrogenase 1

15 a Internode elongation just prior to flowering 1 2

b Gibberellins/ GA/ GAs/ Gibberellic acid 1

16. a Auxins v,

b Help to initiate rooting in stem cuttings/promote flowering
/prevent leaf and fruit drop in early stages/promote abscission
of older mature leave and fruits/ induce I v, 2
parthenocarpy/used as herbicide(used to prepare weed free
lawn/control xylem differentiation and help in cell
division/promote apical dominance/ (any three)

17 a A. Cymose inflorescence 1 l2
B. Recemose inflorescence 1 t2

Cymose: Main axis terminates in a flower/ limited growth/
b 1
flowers are bome in a basipetal order( Older flowers at tip and
younger flowers at the bottom) 3

Racemose
Main axis continues to grow / unlimited growth /
Flowers are borne in a acropetal order(Older 1

flowers at the base and younger at the tip )
( any two differences)

18 a Anaphase of mitosis/ Anaphase %
b i. Centomere split /sister chromatids separate
ii. Chromosomes migration towards two poles/Chromatids move to y2+y2
opposite poles
3
c Growth and developmenV Tissue( cell) repair/ regeneration/
genetic continuity(production of diploid daughter cells with ll2x3
identical genetic compliment/ equational division/ help to
maintain the nucleo-cfloplasmic ratio/help to continuous growth
of plants throughout their life by mitotic division in meristem
(any three)

t9 a. A. Mesophyll cell B. Bundle sheath cell v2+U2

y2
b !!rst plgduct formed in this cycle is four carbon compound 3
(C4 acid / OAA /Oxaloacetic acid)
c Tolerate high temperaturel Higher photosynthetic y2x3
effrciency(have greater productivity of biomass )/ Response
to high light intensity /They lack photorespiration / They have
a special type of leaf anatomy(Kranz anatomy) (any three)

20 a. Glycolysis/ EMP pathway %

b A. Glucose-6-phosphate U4

B.Triose phosphate/Glyceraldehyde-3 -phosphate/PcAl
v4
C.2-phoryhogtyceric acid/2-phosphoglycerate l2PG A U4 3

D. Phospho enol pynrvate/ PEP v4
c
i. aerobic respiration or its explanation
ii. Alcohol fermentation or its explanation
%x3
iii. Lactic acid fermentation or its explanation.

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