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Solutions for Biology, Class 10, ICSE
A plant hormone related with inhibition of senescence is
GA
Reason — GA help in growth, initiate germination, breaks seed dormancy and inhibits senescence.
How many autosomes does a human being have?
44
Reason — Humans have 22 pairs of autosomes and one pair of sex chromosome.
Chromosomes are arranged at equatorial plate in
metaphase
Reason — In metaphase the chromosomes are arranged in equatorial plane and spindles attach to their centromeres.
Which out of these can dissolve chlorophyll?
Methylated spirit and alcohol
Reason — Methylated spirit and alcohol dissolves chlorophyll from the leaves.
In humans, urea is formed in
liver
Reason — The formation of urea occurs in liver and it is filtered out in the kidney.
Assertion (A): Application of ethylene phytohormone induces fruit ripening.
Reason (R): Ethylene is the only hormone which is a gas at ordinary temperature.
Both A and R are true
Reason — Ethylene is a gaseous plant hormone that induces fruit ripening.
Which of the following is an external factor that affects the rate of transpiration?
Carbon dioxide concentration
Reason — Carbon dioxide concentration above 0.03% cause stomatal closure and results in the decrease of transpiration.
Ram went for his driving test. He has to answer many questions regarding this. He was able to give correct answers to all the questions, but was not able to read the numbers given in coloured circles. This was due to
colour blindness
Reason — Colour blindness is a condition in which some people by birth cannot discriminate between certain colours such as red and green. This is due to a genetic defect.
Which layer of eyeball is richly supplied with blood vessels for providing nourishment to the organ?
Choroid
Reason — Choroid layer of eyeball is richly supplied with blood vessels for providing nourishment to it.
Extraordinary decrease in the number of leucocytes is called
leucopenia
Reason — Leucopenia is an extraordinary decrease in white blood cell count.
The passage of white blood corpuscles through unruptured wall of blood vessels is known as
diapedesis
Reason — During any injury or infection the WBCs pass through the wall of blood vessel to reach the site of infection to fight bacteria. This process is referred to as diapedesis.
The rate of comparison of transpiration from both surfaces of a dorsiventral leaf is measured using
Garreau's potometer
Reason — Garreau's potometer helps to compare the rate of transpiration from upper and lower surfaces of leaf.
X-ray machine operator have to take special care to avoid exposure of X-rays.
Which of the following reasons support this statement?
P. X-ray damage the body cells.
Q. Too frequent exposure may cause genetic variations, bone cancer etc.
R. Too much X-rays exposure are not harmful.
Only P and Q
Reason — X-ray damages body cells and may cause genetic variations.
The average ratio of male to female individuals based on XX and XY type of sex-determination, in a human population is
1:1
Reason — XX and XY are equal giving a ratio 1:1.
Harish was crossing the road when he suddenly slipped on a banana peel and fell on the road. After some time the inflamed region developed redness, swelling, pain with increased local heat.
Which of the following is/are involved in the process mentioned above?
(a) Leucocytes
(b) Erythrocytes
(c) Plasma
(d) Lymph
Only a
Reason — Inflammation occurs due to the reaction of tissues to injury and to localized invasion of germs. Here the leucocytes migrate through the walls of the blood vessels through diapedesis and fight against the disease causing germs.
Name the following.
(a) The layer of the eyeball that consists of two types of photoreceptor cells known as rods and cones.
(b) The phenomenon of gradual increase in the average temperature of the surface of the Earth.
(c) Thin, double layered membranous structure enclosing an embryo.
(d) The molecule through which genetic information is transferred from one generation to other.
(e) The process of RBCs (Red Blood Corpuscles) formation.
(a) Retina
(b) Global warming
(c) Amnion
(d) DNA
(e) Erythropoiesis
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) Eyeball, Retina, Sclerotic, Choroids
(b) Cuticle, Palisade tissue, Upper epidermis, Spongy parenchyma
(c) Injured tissue, Fibrinogen, Thromboplastin, Prothrombin
(d) Cortex, Endodermis, Xylem vessels, Pericycle
(e) Initial growth, Increase in size, Cell division, Chromosome replication.
(a) Eyeball, Sclerotic, Choroids, Retina
(b) Cuticle, Upper epidermis, Palisade tissue, Spongy parenchyma.
(c) Injured tissue, Thromboplastin, Prothrombin, Fibrinogen.
(d) Cortex, Endodermis, Pericycle, Xylem vessels.
(e) Initial growth, Chromosome replication, Increase in size, Cell division.
Fill in the blanks with suitable words.
The inner ear or (a) ............... has two main parts (b) ............... and (c) ............... . The cochlea is (d) ............... and looks like a (e) ............... .
The inner ear or (a) membranous labyrinth has two main parts (b) cochlea and (c) semicircular canals . The cochlea is (d) spiral-shaped and looks like a (e) snail shell.
Choose the odd one out from the following terms and name the category to which others belong
(a) Axon, Myelin sheath, Schwann cells, Synapse
(b) Seed shapes, Seed colour, Flower position, Inflorescence.
(c) Hypertension, Diarrhoea, Deafness, Irritation.
(d) Insulin, Glucagon, Thyroxine, Pepsin.
(e) Cretinism, Myxoedema, Goitre, Scurvy.
(a) Odd one: Synapse
Category: Others are parts of a nerve cell.
(b) Odd one: Inflorescence
Category: Others are traits studied by Mendel
(c) Odd one: Diarrhoea
Category: Others are effects of noise pollution.
(d) Odd one: Pepsin
Category: Others are hormones secreted by endocrine glands.
(e) Odd one: Scurvy
Category: Others are hormonal disorders
Match the items given in Column I with the most appropriate ones in Column II and rewrite the correct matching pairs
| Column I | Column II |
|---|---|
| Junction between neuron | Ears |
| Luteal phase | Synapse |
| Auditory nerve | Cranial meninges |
| Protective covering of brain | Progesterone |
| Occipital lobe | Visual perception |
| Testosterone | |
| Neurotransmitters |
| Column I | Column II |
|---|---|
| Junction between neuron | Synapse |
| Luteal phase | Progesterone |
| Auditory nerve | Ears |
| Protective covering of brain | Cranial meninges |
| Occipital lobe | Visual perception |
Potato cubes when placed in water, they become turgid. What will happen to the potato cubes when they are kept in sugar solution?
The potato cubes will become flaccid when kept in sugar solution due to exosmosis.
Define tropic movement.
Growth movements occurring in response to unidirectional external stimuli in a plant part are called tropic movements.
Mention two functions of abscisic acid.
Two functions of abscisic acid (ABA) are:
What are the differences between menarche and menopause?
Differences between menarche and menopause are:
| Menarche | Menopause |
|---|---|
| It is the onset of menstruation in a young female at about the age of 13 years. | It is the permanent stoppage of menstruation in females at about the age of 45 years. |
| It indicates beginning of reproductive age. | It indicates ending of reproductive age. |
Draw a neat and labelled diagram showing the vertical section of a leaf.
Below labelled diagram shows the vertical section of a leaf:
Mention the exact location of amniotic fluid.
The exact location of amniotic fluid is between amnion and embryo.
Differentiate between diastole and systole of cardiac cycle.
Differences between diastole and systole of cardiac cycle are:
| Systole | Diastole |
|---|---|
| Systole refers to contraction phase of the heart. | Diastole refers to expansion phase of the heart. |
| Systole consists of contraction of auricles followed by contraction of ventricles. | Diastole consists of relaxation of ventricles immediately followed by relaxation of auricles. |
State two functions of pericardial fluid.
Two functions of pericardial fluid are:
Name the fluid being taken out through the syringe during amniocentesis process. How is this process helpful?
Amniotic fluid.
Amniocentesis process is helpful in pre-natal diagnosis of genetic diseases and other abnormalities.
Draw a neat and labelled diagram to show the internal view of testis.
Below labelled diagram shows the internal view of testis:
Define glomerular filtrate.
The fluid that enters the renal tubule after the process of ultrafiltration is called glomerular filtrate.
Which gland secretes growth hormone? Also mention its effect on a person due to its deficiency as well as its excess secretion.
Pituitary gland secretes growth hormone. The deficiency of growth hormone causes dwarfism and its excess secretion causes gigantism.
Who among the Dryopithecus and Ramapithecus was more man like?
Ramapithecus was more like man because Ramapithecus walked erect on its hindfeet and had few teeth and some fragments of jaw.
A red coloured pigment A is found in the blood of vertebrates and a few invertebrates. A blue coloured respiratory pigment B is found in the blood of several invertebrates. Name A and B.
A → Haemoglobin
B → Haemocyanin
Given below is a diagram representing the structure of an ovum surrounded by a few sperm cells. Study the diagram and answer the questions that follows.
(a) Where does fertilisation, normally take place?
(b) Mention the chromosome number in egg and zygote in humans.
(c) What is the main function of corona radiata?
(a) The process of fertilisation takes place in the fallopian tube of females.
(b) The chromosome number in human egg (haploid) is 23 and zygote (diploid) is 46.
(c) The main function of corona radiata is to supply vital proteins to the ovum.
Give the exact location of occipital lobe of cerebral cortex.
The occipital lobe of cerebral cortex lies towards the back of the brain between parietal lobe and cerebellum.
Differentiate between thigmotropic and chemotropic movement.
Differences between between thigmotropic and chemotropic movement are:
| Thigmotropic Movement | Chemotropic movement |
|---|---|
| The growth movement of plant parts in response to touch stimulus is called thigmotropic movement. | The growth movement of plant parts in response to nutrient or chemicals is called chemotropic movement. |
| Example — Plants such as sweet peas, Cuscuta and vines have tendrils which coil around other plants in response to one sided contact or touch. | Example — Growth of pollen tube towards the sugary substance secreted by the stigma of the flower. |
Write any two postulates of Darwin's theory.
Two postulates of Darwin's theory are:
Leaf of a green plant is called a food factory. Explain.
The process of photosynthesis is carried out primarily in leaves as they have chlorophyll and numerous stomata. The leaves trap maximum light energy and carry out gaseous exchange required for photosynthesis. Therefore, they are called food factory of plants.
Study the diagram given below and answer the questions that follows.
(a) Identify the structure.
(b) Write one difference in the composition of blood flowing through the blood vessels A or B.
(c) Which part of kidney contains freshly collected urine?
(a) Human excretory system.
(b) Blood flowing through blood vessel 'A' is impure and has more nitrogenous waste, while the blood flowing through blood vessel 'B' is filtered blood and has less nitrogenous waste.
(c) The renal pelvis contains the freshly collected urine.
Expand SAN.
Sino Atrial Valve.
Give differences between interphase and M-phase.
Differences between interphase and M-phase are:
| Interphase | M-phase |
|---|---|
| It consists of growth of cell in size. | It consists of division of cell. |
| It consists of three phases i.e. first growth phase (G1), synthesis phase (S) and second growth phase (G2). | It consist of four phases i.e. Prophase, Metaphase, Anaphase and Telophase. |
What is mutation? Give one example.
Mutation is a sudden change in one or more genes, or in the number or in the structure of chromosomes that results in change of traits. For example, Sickle cell anaemia is a blood disease caused by a gene mutation.
List any two effects of cortisone.
The two effects of cortisone are given below
Study the diagram given below and answer the questions that follows.
(a) Identify the parts indicated 1 and 2.
(b) Name the phenomenon shown in the diagram.
(c) Is the root hair cell unicellular or multicellular?
(a) Parts 1 and 2 are:
(b) Absorption of water by roots (Osmosis)
(c) Root hair is unicellular.
Define mitosis.
Mitosis is the cell division in which one parent cell divides into identical daughter cells.
What are the long terms benefits of the Swachh Bharat Abhiyan?
Following are the long term benefits of Swachh Bharat Abhiyan:
Migration is an important determinant of population change. Explain.
Migration changes not only the population size but also the population composition of urban and rural populations in terms of age and sex composition. In India, rural-urban migration has led to a continuous rise in the population of cities and towns.
In the context of rising human population, name the six main resources that are under pressure.
The six main resources that are under pressure are:
The diagram given below represents an experiment to demonstrate a physiological process taking place in green plants. Answer the questions that follows.
(a) Label the parts A and B in the given figure.
(b) Name the physiological process being demonstrated.
(c) How could the rate of photosynthesis be increased in the given setup?
(a) Parts A and B are:
(b) Photosynthesis.
(c) Rate of photosynthesis can be increased by adding a pinch of NaHCO3, because it releases CO2 in water.