2019 Biology Paper Flashcards
The Earth Summit held in Rio de Janeiro in 1992 was called
- To reduce CO2 emission and global warning.
2.For conservation of biodiversity and sustainable utilization of its benefits.
- To assess threat posed to native species by invasive weed species.
- For immediate steps to discontinue use of CFCs that were damaging the ozone layer.
From chapter 13 / grade 12 biodiversity and conservation / 225
2.For conservation of biodiversity and sustainable utilization of its benefits
NCERT
Biodiversity knows no political boundaries and its conservation is
therefore a collective responsibility of all nations.
The historic Convention on Biological Diversity (‘The Earth Summit’) held in Rio de Janeiro in 1992, called upon all nations to take appropriate measures for conservation of biodiversity and sustainable utilisation of its benefits.
Colostrum the yellowish fluid, secreted by mother during the initial days of lactation is very essential to impart immunity to the newborn infants because it contains:
- Natural Killer cells
- Monocytes
- Macrophages
- Immunoglobulin A
From chapter 2 / grade 12 human reproduction / 38
Immunoglobulin A
NCERT
The mammary glands of the female undergo differentiation during
pregnancy and starts producing milk towards the end of pregnancy by the process called lactation. This helps the mother in feeding the newborn. The milk produced during the initial few days of lactation is called colostrum which contains several antibodies absolutely essential to develop resistance for the new-born babies. Breast-feeding during the initial period of infant growth is recommended by doctors for bringing up a healthy baby. (IgA)
Grass leaves curl inwards during very dry weather.
Select the most appropriate reason from the following:
(1) Closure of stomata
(2) Flaccidity of bulliform cells
(3) Shrinkage of air spaces in spongy mesophyll
(4) Tyloses in vessels
From chapter 6 / grade 11 anatomy of flowering plants / 77
(2) Flaccidity of bulliform cells
NCERT
In grasses, certain adaxial epidermal cells along the veins modify
themselves into large, empty, colourless cells. These are called bulliform cells. When the bulliform cells in the leaves have absorbed water and are turgid, the leaf surface is exposed. When they are flaccid due to water stress, they make the leaves curl inwards to minimise water loss.
The shorter and longer arms of a submetacentric chromosome are referred to as
- s-arm and l-arm respectively
- p-arm and q-arm respectively
- q-arm and p-arm respectively
- m-arm and n-arm respectively
From chapter 8 / grade 11 cell the unit of life / 161
- p-arm and q-arm respectively
NCERT
The sub-metacentric chromosome has centromere slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm. (add the image)
one shorter arm - p arm
one longer arm - q arm
Respiratory Quotient (RQ) value of tripalmitin is
- 0.9
- 0.7
- 0.07
- 0.09
From chapter 12 / grade 11 respiration in plants / 164
- 0.7
NCERT
Let us now look at another aspect of respiration. As you know, during
aerobic respiration, O2 is consumed and CO2 is released. The ratio of the volume of CO2 evolved to the volume of O2 consumed in respiration is called the respiratory quotient (RQ) or respiratory ratio.
Add the image
The respiratory quotient depends upon the type of respiratory
substrate used during respiration.
When carbohydrates are used as substrate and are completely
oxidised, the RQ will be 1, because equal amounts of CO2 and O2
are evolved and consumed, respectively, as shown in the equation below :
Add the image
When fats are used in respiration, the RQ is less than 1. Calculations
for a fatty acid, tripalmitin, if used as a substrate is shown:
Add the image
When proteins are respiratory substrates the ratio would be about
0.9.
What is important to recognise is that in living organisms respiratory
substrates are often more than one; pure proteins or fats are never used as respiratory substrates.
Which of the following is a commercial blood cholesterol lowering agent?
(1) Cyclosporin A
(2) Statin
(3) Streptokinase
(4) Lipases
From chapter 8 / grade 12 microbes in human welfare / 153
(2) Statin
NCERT
Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.
Which of the following is the most important cause for animals and plants being driven to extinction?
(1) Habitat loss and fragmentation
(2) Drought and floods
(3) Economic exploitation
(4) Alien species invasion
From chapter 13 / grade 12 biodiversity and conservation / 222
(1) Habitat loss and fragmentation
NCERT
Habitat loss and fragmentation: This is the most important
cause driving animals and plants to extinction.
Which part of the brain is responsible for thermoregulation?
- Cerebrum
- Hypothalamus
- Corpus callosum
- Medulla oblongata
From chapter 18 / grade 11 neural control and coordination / 236
Hypothalamus
NCERT
The hypothalamus contains a number of centres which control
body temperature, urge for eating and drinking.
Consider following features
(a) Organ system level of organization
(b) Bilateral symmetry
(c) True coelomates with segmentation of body
Select the correct option of animal groups which possess all the above characteristics
(1) Annelida, Arthropoda and Chordata
(2) Annelida, Arthropoda and Mollusca
(3) Arthropoda, Mollusca and Chordata
(4) Annelida, Mollusca and Chordata
From chapter 4 / grade 11 animal kingdom / 51
(1) Annelida, Arthropoda and Chordata
Add the image 2
Select the correct sequence of organs in the alimentary canal of cockroach starting from mouth:
- Pharynx - Oesophagus - Crop - Gizzard - Ileum - Colon - Rectum
- Pharynx - Oesophagus - Gizzard - Crop - Ileum - Colon - Rectum
- Pharynx - Oesophagus - Gizzard - Ileum - Crop - Colon - Rectum
- Pharynx - Oesophagus - Ileum - Crop - Gizzard - Colon - Rectum
From chapter 7 / grade 11 structural organisation in animals /
- Pharynx - Oesophagus - Crop - Gizzard - Ileum - Colon - Rectum
Add the image
Which of the following muscular disorders is inherited?
(1) Tetany
(2) Muscular dystrophy
(3) Myasthenia gravis
(4) Botulism
From chapter 17 / grade 11 locomotion and movement / 227
(2) Muscular dystrophy
NCERT
Muscular dystrophy:
Progressive degeneration of skeletal muscle mostly due to
genetic disorder.
The ciliated epithelial cells are required to move particles or mucus in a specific direction. In humans, these cells are mainly present in:
- Bile duct and bronicholes
- Fallopian tubes and Pancreatic duct
- Eustachian tube and Salivary duct
- Bronicholes and Fallopian tubes
From chapter 7 / grade 11 structural organisation in animals /
- Bronchioles and Fallopian tubes
Add the image
Match the Column –I with Column –II
Column-I Column –II
Wave i) Depolarization of ventricles
QRS complex ii) Repolarization of ventricles
T-wave iii) Coronary ischemia
Reduction in the size of T-wave iv) Depolarization of atria
v) Repolarization of atria
From chapter 15 / grade 11 body fluids and circulation / 201
Select the correct option-
(1) a - iv, b - i, c - ii, d - iii
(2) a - iv, b - i, c - ii, d - v
(3) a - ii, b - i, c - v, d - iii
(4) a - ii, b - iii, c - v, d - iv
(1) a - iv, b - i, c - ii, d - iii
Wave - iv) Depolarization of atria
QRS complex - i) Depolarization of ventricles
T-wave - ii) Repolarization of ventricles
Reduction in the size of T-wave - iii) Coronary ischemia
NCERT
Add the image
The P-wave represents the electrical excitation (or depolarisation) of the atria, which leads to the contraction of both the atria.
The QRS complex represents the depolarisation of the ventricles,
which initiates the ventricular contraction. The contraction starts shortly after Q and marks the beginning of the systole.
The T-wave represents the return of the ventricles from excited to normal state (repolarisation). The end of the T-wave marks the end of systole.
- Which one of the following is not a method in situ conservation of biodiversity?
(1) Biosphere Reserve
(2) Wildlife Sanctuary
(3) Botanical Garden
(4) Sacred Grove
From chapter 13 / grade 12 biodiversity and conservation / 225
(3) Botanical Garden
NCERT
under In-situ conservation
In India, ecologically unique and biodiversity-rich regions are legally
protected as biosphere reserves, national parks and sanctuaries. India now has 14 biosphere reserves, 90 national parks and 448 wildlife sanctuaries. India has also a history of religious and cultural traditions that emphasised protection of nature. In many cultures, tracts of forest were set aside, and all the trees and wildlife within were venerated and given total protection.
Such sacred groves are found in Khasi and Jaintia Hills in Meghalaya, Aravalli Hills of Rajasthan, Western Ghat regions of Karnataka and Maharashtra and the Sarguja, Chanda and Bastar areas of Madhya Pradesh. In Meghalaya, the sacred groves are the last refuges
for a large number of rare and threatened plants.
Ex situ Conservation–
In this approach, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care.
Zoological parks, botanical gardens and wildlife safari parks serve this purpose.
In a species, the weight of a newborn ranges from 2 to 5 kg.
97% of the newborn with an average weight between 3 to 3.3 kg survive whereas 99% of the infants born with weight from 2 to 2.5 kg or 4.5 to 5 kg die. Which type of selection process is taking place?
(1) Directional Selection
(2) Stabilizing Selection
(3) Disruptive Selection
(4) Cyclical Selection
From chapter 6 / grade 12 evolution / 121
(2) Stabilizing Selection
NCERT
Natural selection can lead to stabilisation (in which more individuals acquire mean character value)
The correct sequence of phases of cell cycle is :
(1) M G1 G2 S
(2) G1 G2 S M
(3) S G1 G2 M
(4) G1 S G2 M
From chapter 10 / grade 11 cell cycle and cell division / 121
(4) G1 S G2 M
NCERT
Add the image
How does steroid hormone influence cellular activities?
(1) Changing the permeability of the cell membrane
(2) Binding to DNA and forming a gene hormone complex
(3) Activating cyclic AMP located on the membrane
(4) Using aquaporin channels as second messenger
From chapter 19 / grade 11 chemical coordination and integration /
(2) Binding to DNA and forming a gene hormone complex
CHECK THIS IN NCERT
Which of the following statements is not correct?
(1) Lysosomes have numerous hydrolytic enzymes
(2) The hydrolytic enzymes of lysosomes are active under acidic pH
(3) Lysosomes are membrane bound structures
(4) Lysosomes are formed by the process of packaging in the endoplasmic reticulum
From chapter 8 / grade 11 cell the unit of life / 96
(4) Lysosomes are formed by the process of packaging in the endoplasmic reticulum
NCERT
- These are membrane bound vesicular structures formed by the process of packaging in the golgi apparatus.
- The isolated lysosomal vesicles have been found to be very rich in almost all types of hydrolytic enzymes (hydrolases – lipases, proteases, carbohydrases) optimally active at the acidic pH.
These enzymes are capable of digesting carbohydrates, proteins, lipids and nucleic acids.
Which one of the following statements regarding post-fertilization development in flowering plants is incorrect?
(1) Ovary develops into fruit
(2) Zygote develops into embryo
(3) Central cell develops into endosperm
(4) Ovules develop into embryo sac
From chapter 1 / grade 12 sexual reproduction in flowering plants
(4) Ovules develop into embryo sac
NCERT
As ovules mature into seeds, the ovary develops into a fruit, i.e., the
transformation of ovules into seeds and ovary into fruit proceeds
simultaneously (page 20)
After fertilisation, ovary develops into fruit and ovules
develop into seeds. (Summary)
Concanavalin A is
- An alkaloid
- An essential oil
- An lectin
- A pigment
From chapter 9 / grade 11 bio molecules / 108
- An lectin
Add the image
Which one of the following equipment is essentially required for growing microbes on a large scale, for industrial production of enzymes?
(1) BOD incubator
(2) Sludge digester
(3) Industrial oven
(4) Bioreactor
From chapter 9 / grade 12 biotechnology: principles and processes (174)
(4) Bioreactor
NCERT
Small volume cultures cannot yield appreciable quantities of products.
To produce in large quantities, the development of bioreactors, where large volumes (100-1000 litres) of culture can be processed, was required.
Thus, bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes, etc., using microbial plant, animal or human cells.
A bioreactor provides the optimal conditions for achieving the desired product by providing optimum growth conditions (temperature, pH, substrate, salts, vitamins, oxygen)
Add the image
Consider the following statement :
(A) Coenzyme or metal ion that is tightly bound to enzyme protein is called the prosthetic group.
(B) A complete catalytic active enzyme with its bound prosthetic group is called apoenzyme.
Select the correct option.
(1) Both (A) and (B) are true.
(2) (A) is true but (B) is false.
(3) Both (A) and (B) are false.
(4) (A) is false but (B) is true
From chapter 9 / grade 11 bio molecules (118)
(3) Both (A) and (B) are false.
NCERT
Three kinds of cofactors may be identified:
prosthetic groups, co-enzymes and metal ions.
Prosthetic groups are organic compounds and are distinguished from
other cofactors in that they are tightly bound to the apoenzyme.
For example, in peroxidase and catalase, which catalyze the breakdown of hydrogen peroxide to water and oxygen, haem is the prosthetic group and it is a part of the active site of the enzyme
Purines found both in DNA and RNA are
(1) Adenine and thymine
(2) Adenine and guanine
(3) Guanine and cytosine
(4) Cytosine and thymine
From chapter 5 / grade 12 molecular basis of inheritance /80
(2) Adenine and guanine
NCERT
There are two types of nitrogenous bases –
Purines (Adenine and Guanine), and
Pyrimidines (Cytosine, Uracil and Thymine).
Cytosine is common for both DNA and RNA and
Thymine is present in DNA.
Uracil is present in RNA at the place of Thymine
Select the correct sequence for transport of sperm cells in male reproductive system.
(1) Testis Epididymis Vasa efferentia Rete testis Inguinal canal Urethra
(2) Seminiferous tubules Rete testis Vasa efferentia Epididymis Vas deferens Ejaculatory duct Urethra Urethral meatus
(3) Seminiferous tubules Vasa efferentia Epididymis Inguinal canal Urethra
(4) Testis Epididymis Vasa efferentia Vas deferens Ejaculatory duct Inguinal canal Urethra Urethral meatus
(2) Seminiferous tubules Rete testis Vasa efferentia Epididymis Vas deferens Ejaculatory duct Urethra Urethral meatus
NCERT
Add the diagram
Match the hominids with their correct brain size :
Homo habilis i) 900 cc
Homo neanderthalensis ii) 1350 cc
Homo erectus iii) 650 - 800 cc
Homo sapiens iv) 1400 cc
(1) a - iii, b - i, c - iv, d - ii
(2) a - iii, b - ii, c - i, d - iv
(3) a - iii, b - iv, c - i, d - ii
(4) a - iv, b - iii, c - i, d - ii
From chapter 6 / grade 12 evolution / 125
(3) a - iii, b - iv, c - i, d - ii
Homo habilis - iii) 650 - 800 cc
Homo neanderthalensis - iv) 1400 cc
Homo erectus - i) 900 cc
Homo sapiens - ii) 1350 cc
NCERT
This creature was called the first human-like being the hominid and was called Homo habilis. The brain capacities were between
650-800cc. They probably did not eat meat.
Fossils discovered in Java in 1891 revealed the next stage, i.e.,
Homo erectus about 1.5 mya. Homo erectus had a large brain around 900cc. Homo erectus probably ate meat.
The Neanderthal man with a brain size of 1400cc lived in near east and central Asia between 1,00,000-40,000 years back. They used hides to protect their body and buried their dead.
Homo sapiens arose in Africa and moved across continents and developed into distinct races. During ice age between 75,000-10,000 years ago modern Homo sapiens arose. (1350)
Pre-historic cave art developed about 18,000 years ago. One such cave paintings by Pre-historic humans can be seen at Bhimbetka rock shelter in Raisen district of Madhya Pradesh.
Agriculture came around 10,000 years back and human settlements
started. The rest of what happened is part of human history of growth and decline of civilisations.
Variations caused by mutation, as proposed by Hugo de Vries are
(1) random and directional
(2) random and directionless
(3) small and directional
(4) small and directionless
From chapter 6 / grade 12 evolution / 119
(2) random and directionless
NCERT
Hugo deVries based on his work on evening primrose brought forth the idea of mutations – large difference arising suddenly in
a population.
He believed that it is mutation which causes evolution and
not the minor variations (heritable) that Darwin talked about.
Mutations are random and directionless
Which of the following pair of organelles does not contain DNA?
(1) Mitochondria and Lysosomes
(2) Chloroplast and Vacuoles
(3) Lysosomes and Vacuoles
(4) Nuclear envelope and Mitochondria
From chapter 8 / grade 11 cell the unit of life
(3) Lysosomes and Vacuoles
CHECK NCERT
Due to increasing air-borne allergens and pollutants, many people in urban areas are suffering from respiratory disorder causing wheezing due to
(1) benign growth on mucous lining of nasal cavity
(2) inflammation of bronchi and bronchioles
(3) proliferation of fibrous tissues and damage of the alveolar walls
(4) reduction in the secretion of surfactants by pneumocytes
From chapter 14 / grade 11 breathing and exchange of gases / 190
(2) inflammation of bronchi and bronchioles
NCERT
Asthma is a difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles.
Select the incorrect statement.
(1) Male fruit fly is heterogametic
(2) In male grasshoppers 50% of sperms have no sex-chromosome
(3) In domesticated fowls, sex of progeny depends on the type of sperm rather than egg
(4) Human males have one of their sexchromosome much shorter than the other
From chapter 4 / grade 12 principles of inheritance and variation
(3) In domesticated fowls, sex of progeny depends on the type of sperm rather than egg
NCERT - CHECK THIS QUESTION
DNA precipitation out of a mixture of biomolecules can be achieved by treatment with
(1) Isopropanol
(2) Chilled ethanol
(3) Methanol at room temperature
(4) Chilled chloroform
From chapter 9 / grade 12 biotechnology : principles and processes / 171
(2) Chilled ethanol
NCERT
Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol.
Select the correct group of biocontrol agents.
(1) Bacillus thuringiensis, Tobacco mosaic virus, Aphids
(2) Trichoderma, Baculovirus, Bacillus thuringiensis
(3) Oscillatoria, Rhizobium, Trichoderma
(4) Nostoc, Azospirillium, Nucleopolyhedroviru
From chapter 8 / grade 11 microbes in human welfare / 157
(2) Trichoderma, Baculovirus, Bacillus thuringiensis
NCERT
A biological control being developed for use in the treatment of plant
disease is the fungus Trichoderma. Trichoderma species are free-living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens
Baculoviruses are pathogens that attack insects and other arthropods. The majority of baculoviruses used as biological control agents are in the genus Nucleopolyhedrovirus
An example of microbial biocontrol agents that can be
introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (often written as Bt).
Match the following organisms with the products they produce
Lactobacillus i) Cheese
Saccharomyces cerevisiae ii) Curd
Aspergillus niger iii) Citric Acid
Acetobacter aceti iv) Bread
v) Acetic acid
Select the correct option.
(1) (a)-(ii), (b)-(iv), (c)-(v), (d)-(iii)
(2) (a)-(ii), (b)-(iv), (c)-(iii), (d)-(v)
(3) (a)-(iii), (b)-(iv), (c)-(v), (d)-(i)
(4) (a)-(ii), (b)-(i), (c)-(iii), (d)-(v)
From Chapter 8 / grade 11 microbes in human welfare / 151-153
(2) (a)-(ii), (b)-(iv), (c)-(iii), (d)-(v)
Lactobacillus - ii) Curd
Saccharomyces cerevisiae - iv) Bread
Aspergillus niger - iii) Citric Acid
Acetobacter aceti - v) Acetic acid
NCERT
A. Micro-organisms such as Lactobacillus and others
commonly called lactic acid bacteria (LAB) grow in milk and convert it
to curd
B. Similarly the dough, which is used for making bread, is fermented using baker’s yeast (Saccharomyces cerevisiae).
Microbes are also used for commercial and industrial production of
certain chemicals like organic acids, alcohols and enzymes.
C. Examples of acid producers are Aspergillus niger (a fungus) of
citric acid,
D. Acetobacter aceti (a bacterium) of acetic acid;
Persistent nucellus in the seed is known as:
- Chalaza
- Perisperm
- Hilum
- Tegmen
From chapter 1 / grade 12 sexual reproduction in flowering plants / 20
Perisperm
NCERT
This residual, persistent nucellus is the perisperm.
What map unit (Centimorgan) is adopted in the construction of genetic maps?
(1) A unit of distance between two expressed genes representing 10% cross over.
(2) A unit of distance between two expressed genes representing 100% cross over.
(3) A unit of distance between genes on chromosomes, representing 1% cross over.
(4) A unit of distance between genes on chromosomes, representing 50% cross over
From chapter 4 / grade 12 principles of inheritance and variation
(3) A unit of distance between genes on chromosomes, representing 1% cross over.
CHECK NCERT
What would be the heart rate of a person if the cardiac output is 5 L, blood volume in the ventricles at the end of diastole is 100 mL and at the end of ventricular systole is 50 mL?
(1) 50 beats per minute
(2) 75 beats per minute
(3) 100 beats per minute
(4) 125 beats per minute
(3) 100 beats per minute
NCERT
CHECK NCERT
This sequential event in the heart which is cyclically repeated is called
the cardiac cycle and it consists of systole and diastole of both the atria and ventricles. As mentioned earlier, the heart beats 72 times per minute, i.e., that many cardiac cycles are performed per minute. From this it could be deduced that the duration of a cardiac cycle is 0.8 seconds. During a cardiac cycle, each ventricle pumps out approximately 70 mL of blood which is called the stroke volume. The stroke volume multiplied by the heart rate (no. of beats per min.) gives the cardiac output. Therefore, the cardiac output can be defined as the volume of blood pumped out by each
ventricle per minute and averages 5000 mL or 5 litres in a healthy individual. The body has the ability to alter the stroke volume as well as the heart rate and thereby the cardiac output. For example, the cardiac output of an athlete will be much higher than that of an ordinary man.
