Question 1

Question 1(vi)During the mechanism of opening and closing of stomata, the important factor isthe protein content of the cellsthe turgid and flaccid state of the guard cellthe starch content of the cellsthe presence of chloroplast in the guard cell

Accepted Answer

the turgid and flaccid state of the guard cellReason — Stomata open when guard cell are turgid and closes when guard cells are flaccid.

Question 2

Question 1(viii)Convex lens is used for the correction of long sightedness. Which of the following reasons support this statement?P. The image of near by object falls behind the retina.Q. The lens is too flat resulting in hypermetropia.R. Uneven curvature of cornea.Only ROnly QOnly P and ROnly P and Q

Accepted Answer

Only P and QReason — In hypermetropia, the lens becomes too flat and therefore the image is formed behind the retina. A convex lens corrects this problem.

Question 3

Question 1(xii)The synthesis phase in the cell cycle is called so for the synthesis of moreRNARNA and proteinDNAGlucose

Accepted Answer

DNAReason — DNA duplication occurs in the synthesis phase of the cell cycle.

Question 4

Question 1(xiv)Chief function of lymphocytes in mammals isphagocytosiscoagulationoxygen transportNone of the above

Accepted Answer

phagocytosisReason — Lymphocytes in mammals engulf the foreign particles. This is known as phagocytosis.

Question 5

Question 2(i)Name the following.(a) The layer of the eyeball that is sensitive to the light.(b) One harmful effect of ozone layer depletion.(c) A disc-like structure, which plays a role in nutrition, respiration and excretion of embryo.(d) The point of attachment of non-sister chromatids of homologous chromosomes where crossing over takes place.(e) Name the organism studied for industrial melanism.

Accepted Answer

(a) Retina(b) Skin cancer(c) Placenta(d) Chiasma(e) Biston bitularia (Peppered moth)

Question 6

Question 2(ii)Arrange and rewrite the terms in each group in the correct order so as to be in a logical sequence beginning with the term that is underlined.(a) Reproductive age, Menarche puberty, Menstruals, Menopause(b) Glucose, CO2 and H2O, Light and Chlorophyll, Oxygen(c) Axon, Nissl's granules, Cyton, Dendrites(d) Adrenal gland, Epinephrine, Pituitary gland, Adrenocorticotropic.(e) Genes, Chromosome, Allele, Chromatin

Accepted Answer

(a) Menarche puberty, Reproductive age, Menstruals, Menopause.(b) CO2 and H2O, Light and Chlrophyll, Oxygen, Glucose(c) Nissl's granules, Cyton, Axon, Dendrites.(d) Pituitary gland, Adrenocorticotropic hormone, Adrenal gland, Epinephrine.(e) Allele, Genes, Chromatin, Chromosome

Question 7

Question 2(iii)Fill in the blanks with suitable words.Blood in human beings flows (a) ............... in the heart before it completes (b) ............... round. It is comprised of one short pathway, i.e. (c) ............... circulation and another long pathway, i.e. (d) ............... circulation. Due to this reason, the blood flow in humans is known as (e) ............... circulation.

Accepted Answer

Blood in human beings flows (a) twice in the heart before it completes (b) one round. It is comprised of one short pathway, i.e. (c) pulmonary circulation and another long pathway, i.e. (d) systemic circulation. Due to this reason, the blood flow in humans is known as (e) double circulation.

Question 8

Question 2(iv)Identify the odd one out from the following terms and name the category to which other three belong.(a) Goitre, Cretinism, Myxoedema, Acromegaly(b) Pineal, Thyroid, Adrenal, Pancreas(©) Cornea, Choroid, Iris, Pupil(d) Dominance, Segregation, Independent assortment, Linkage(e) Eutrophication, Oil spills, Algal bloom, Acid rain

Accepted Answer

(a) Odd one: AcromegalyCategory: Others are disorders of thyroid hormone.(b) Odd one: PancreasCategory: Others are only Endocrine glands(c) Odd one: CorneaCategory: Others are parts of middle layer of eye ball(d) Odd one: LinkageCategory: Others are related to Mendel's laws of inheritance.(e) Odd one: Acid rainCategory: Others are related to water pollution

Question 9

Question 2(v)Match the items given in Column I with the most appropriate ones in Column II and rewrite the correct matching pairsColumn IColumn IIInner portion of cerebrumSocket of the skullLensMyelinated sheathOrbitsEntry of reflected lightVas deferensWhite matterNodes of RanvierTympanum Carries sperms Grey matter Synapse

Accepted Answer

Column IColumn IIInner portion of cerebrumWhite matterLensEntry of reflected lightOrbitsSocket of the skullVas deferensCarries spermsNodes of RanvierMyelinated sheath

Question 10

Question 3(i)Haemophilia is a genetic disorder in which the sufferers are at risk of bleeding to death. What are the chances of a girl child to be haemophilic if her mother is normal and father is haemophilic?

Accepted Answer

When the mother is normal and father is haemophilic, the chances of the girl child to be haemophilic is extremely low. Haemophilia is an X-linked recessive genetic disorder caused by mutations in genes located on the X chromosome. Since, the girl inherits two X chromosomes, one from father and one from mother, the chance of both X chromosomes carrying the recessive mutation is indeed rare.

Question 11

Question 3(ii)What is the significance of double circulation in human beings?

Accepted Answer

Double circulation ensures that the oxygenated blood and deoxygenated blood are separated. This increases the efficiency of oxygen supply.

Question 12

Question 3(iii)State two functions of pituitary gland.

Accepted Answer

Two functions of pituitary gland are:It controls the function of all other endocrine glands.Secretes Growth hormone responsible for normal growth.

Question 13

Question 3(iv)What is hyaluronidase? What is its effect on ovum?

Accepted Answer

Hyaluronidase is an enzyme secreted by the acrosome of the sperm. It dissolves the zona pellucida — the wall of ovum and penetrates the egg.

Question 14

Question 3(v)Draw a well-labelled diagram of a neuron.

Accepted Answer

Labelled diagram of a neuron is shown below:

Question 15

Question 4(ii)How is the sex of a child determined in human beings?

Accepted Answer

In humans, the males have 'XY' chromosomes and females have 'XX' chromosome as sex chromosomes. Therefore, 50% male gametes have X chromosome and other 50% have Y chromosome. The females have all gametes with X chromosome. The sex of the child is determined at the time of fertilization. If male gamete with X chromosome fertilizes with female gamete, it leads to a female child whereas if a gamete with Y chromosome fertilizes with female gamete, it leads to a male child.

Question 16

Question 4(iv)What are the differences between gene and allele?

Accepted Answer

GeneAlleleGene is part of the DNA structure which decides the genetic traits.Alleles are different variants of a gene.Genes determine an organism's genotype.Alleles determine an organism's phenotype.

Question 17

Question 4(v)Draw a schematic diagram of cross section of a part of root showing cell conduction of water from a root hair to xylem.

Accepted Answer

Labelled schematic diagram of cross section of a part of root showing cell conduction of water from a root hair to xylem is shown below:

Question 18

Question 5(i)Define demography.

Accepted Answer

Demography is the statistical study of human population specifically with reference to size and density, distribution and other vital statistics.

Question 19

Question 5(iii)In an experimental set up pieces of dry cobalt chloride paper are attached to the two surfaces of a dicot leaf and held in position by two glass slides on either side tied-together by elastic bands or hold by clips. The leaf remain attached to its own plant. What will be your observation after some time?

Accepted Answer

The piece of paper which is facing the upper surface of the leaf will not turn pink or turns pink in a much longer time and the one on the lower surface of the leaf turns pink, after some time. This shows that more transpiration takes place from the lower surface of leaf because of the numerous stomata found on it.

Question 20

Question 5(v)The figure given below represents surgical method of contraception. Study the figure and answer the questions that follows.(a) Name the surgical method of contraception shown in figure.(b) Define method given in (a).(c) Identify the label 'A'.

Accepted Answer

(a) Tubectomy(b) In this method, the Fallopian tubes (oviducts) are cut or ligated, i.e. tied with nylon thread to close the passage of the egg.(c) A → Oviduct.

Solved Sample Paper 5

Section A

Section B