ST.

STEPHEN' S SCHOO.
PRE-BOARD EXAMINATION
- DUM DUM
2024- 25
SUBJECT- BIOLOGY
Class --X
Reading Time: 15 Minutes
Writing time: 2 Hours
Full Marks: 80

Candidates are allowedadditional 15 minutes for only

reading the paper. They must NOT
start writing during this time.

Section Iis compulsory. Attemptany four questions from

Section lI.
The intended marks for (questions or parts of
questions are given in brackets [].

SECTIONI(40 MARKS)
(Attempt allQuestions from this section.)

Ouestion 1: select the correct answers to the questions from the given
options (Do notcopy the questions. Write the correct answer only) {15l
i. Ahaemophilic man marries anormal homozygous woman. What is the
probability that their son will be haemophilic?
a. 100%
b. 75%
C. 50%
d. 0%
ii. Water absorption by roots occurs when
a. Solute concentration is high in cell sap.
b. Solute concentration insoil is high.
C. There is nolight.

Pg. 1
 d. The plant is respirating rapidly.
Assertion (A): soakedseeds burst their seed coats
Reason(R): This is because of cohesive force.
a. Ais true and R is false.
b. A is false and R is
true.
C. Both A
andRaretrue.
d. Botha and Rare false.
0V. LUBB is heard at the start of P. while DUP is heardat the start
of Q.
a. P. ventricular systole, Q.-- Atrial diastole.
b. P.- Atrialsystole, Q- Ventriculardiastole
C. P-Ventricular diastole, )-
Ventricular systole
d. P-Ventricular systole, 0-
Ventricular diastole.
V.
After mitotic division afemale human cell will
have
a. 44 + XY
b. 44 + XX
chromosomne
C. 22 + X
chromosomne
chromosome
d. 22 + Y
chromosome
vi. Which one of the following will not directly affect transpiration?
a. Temperature
b. Light
C. Wind speed
d. Chlorophyll contentof leaves.
vii. Surgical methodof sterilization in a womaninvolves cutting and tying of
a. Ureter
b. Uterus
C. Urethra
d. Oviduct
viii. Abiology teacher askedstudenisto mentiontwo abnoma
consituenis of urine:
Anushka said : bile pigment and blood.
Radha said: gtuICOSe and urea
Ritishasaid:glucOse and albuain.
 Akira said: blood
Who is COrect? and urea.
a.
b. Anushka and Ritisha
C. Anushka and Akira
d.
Ritisha and Akira
ix, Radhaand Akira
The twins
called formed from : a single ovum fertilised by single sperm are
a. Homozygous twins
b. Fraternal twins
G. Identical twins
d. None of the
X. above
Agardener wants the
plants in his garden to be bushy for which he
the plants. Whiletrimming the plants he renmoves a plant hormone. trims
The
plant hormone is
a. Gibberellin
b. Cytokinin
C. Auxins
d. Ethylene
Xi. Which one of the following is not a part of
a. Natural selection Darwin's theory
b. Use and disuse a body parts.
C. Struggle for existence.
d. Variation.
xi. Synthesis of millk in female is under the control of the hormone called
a. Oxytocin
b, ADH
C. Prolactin
d. Progesterone
xii!. Whichchemical reaction occurs during photosynthesis
a. Carbon dioxicde is reduced and water is Oxidised
b. Water is reduced and carbon dioxid: is oxidiset
 oxidised
C. Both carbon dioxide and water are
d. Both carbon dioxide and water are reduced

is
xiv. Prime sOurce of chlorofluorocarbon
a. Vehicular emission
b. Refrigeration equipment
C. Sewage
d. Effluents
XV. Assertion(A): Dominant alleles can express themselves only in
homozygous condition.
Reason (R): Dominant alleles support recessive alleles and allow them
toexpress, even in heterozygous condition.
a. Both A and Rare true.
b. Both A andR are false
C. Ais true R is false
d. Ris true Ais false

Question 2:
a. Name the following: [5]
Notch likearea of the kidney from which the ureter originates.
Process ofconversion of several molecules of glucose into
starch.
iii. SuCcessorsof Homoerecius.
iV. Relative concentraion of ihesoluions thatdeiermine the
directionand exient of diffusion.
V. Partof the car associated with mainiaining static balance.

b. Choose the oddi one out írom ihe following ierms andnarne the
catogory io which the others belong: [5]
Vas deferens, Fallopian tube, Epidicymis, Cowper's gland.
Sneezing. Coughing, Biinking, Typing.
Eosinopil, \onocyte, Bascphi, Neuirophit.
imbibiticn, Active transport, Osnosis, Diifusior
 V.

Sulphur dioxide, Cobalt 60, Carbon monoxide, Carbon dioxide.

C.

Complete the paragraph by inserting appropriate words

[5]
in the blanks:
The
innermost
sensitive to sensitive llayer of eye is
dim The cells are
are light which contain the pigment
sensitive to bright light and contain the pigment The cells

d.
Arrange and rewrite the terms in each group in the correct
be
in alogical order so as to
Sequence beginning with the term that is
i. underlined. J5]
Upper epidermis, spongy cells,
stoma, palisade tissue,sub
ii.
stomatal space.
Renal artery, renal vein, efferent arteriole,
afferent arteriole,
iii. glornerulus.
DNA,
0v.
chromosome, nucle0some,histone, chromatinfibre.
Absorption of light energy, release of oxygen, carbon fixation,
formation of ATP and NADPH, photolysis of water.
V.
Intestinal artery, hepatic portal vein,hepatic vein,intestine,
liver.

e. Match the items given in Column i with the most appropriate ones in
Columnlland rewrite the correct matching pairs: [5]

COLUMiN! COLUMN I
a. Mortality Areaof best vision
b. Light reaction Hyper secretion of thyroxine
Myxoedema Number of death per 1000 of population
d. Natality Grana
e. Macula Iutea Stroma
Area of no vision

Pg. 5
 Number of birth per 1000of
Hyposecretion of thyroxine population

SECTION H
(40 MARKS)
(Attempt Any Four Questions from this section.)
Question 3
i. Name the shortest phase of the interphase of cell
cycle. [1]
ii. State the function of eustachian tube. (2]
ii. State the reason for generation of great pressure in
glomerulus
during the synthesisof urine. [2]
0V. Differentiate between sympathetic nervous system and
parasympathetic nervous system based on location. [2]
V. Given below is a diagram on plant physiology. Study the same and
answer the questions that follow: (3}
 a.
What is the aimof the
b. experiment?
Name the tissue that has
been removed?
C. State your
observation 24hrs of the experiment.
after
Question 4
i.
Apatient's blood suddenly shows
the normal value.What is the increase in number of RBCthan
[1] technical term for
the above
condition?
i.
Expand the following: [21
a. IAA
b. ABA
iii. Apatient with
blood type B is in urgent need of a blood
but the blood bank has limited transfusion,
stock. Which blood type can be safely
transfuse intothis patient andwhy? [2]
iv. How the process of transpiration regulates the
plants? [2]
temperature in
V. The diagram given below represents certain
stage of Mitosis. [3]

Pg.7
 a. ldentify the stage.
b. Give one reason tO Support your answer In 'a'
C. How many daughter cell will be produced if the
given celL
undergoes meiosis?
QUestion 5
i. Name the process of meiosiswhere genetic
[1]
recombination occurs.
ii. Differentiate between Homo habilis and Homo erectus based on
cranial capacity. [2]
ii. Schematically show reflex arc. (2]
0v. Mr. Dasof 55 years of age hasdifficulty toread books when kept
close tohis eyes. Name the defect of the eye he is suffering from and
how it can be rectified? [21
V. Thediagram given below representsaplant movement. Answer the
following questions. [3]
 A

a. Name the tropic

b. Label part A. movement shown in the diagram.
C. What is part A
attracted to?
Question 6.
i.
Name the hormone which helps in
birth. [1] uterine contraction during child
i. Howdoes insulin reduces the
blood
iii. Whythe walls of the artery is more glucose level. [2]
thicker than the walls ofthe
veins? [2]
iv. Name the hormone that controls the
working of sympathetic nervous
systemn. Mention it's effect on heart rate. [21
V. Mr. Menonsuddenly felt pain onthe left
side of his chest and was
rushed tothe hOspital. He was diagnosed for heart
attack. [3]

pg.3
 a. Blockage in which blood vessel causes
heart attack?
b. Namne the medical term for heart
attack.
C. What is technical term given for the chest
pain due to heart
attack?
Question7
ii
Define allele. (1]
Apregnant woman has Rh negative blood, and her partner has kn
Positive blood. Explain whyihis situation mightbe concern in
SeCond
pregnancy? [2]
iii.
Mention anytwo effects of acid rain. [2]
iv. What is the function of
serminiferoustubule2 Name the cells which
V.
synthesise testosterone. [2]
Draw a neat labelled diagram of human
urinary system. (3]
Question &
i. Narnethe enzyme present intear. (1]
ii. Mention the roie of FSH and LH in the process of
reproduction. (2]
Aplant cell when dipped in Solution Agot plasmolysed. To
back it is again dipped in another solution B. identify Aand recover
i
B. (2]
0V. Mention the location and function of ear ossicles. I21
V. Draw a neat labeled diagramof chloroplast. [31

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