๐ Download Biology Question Paper PDF - SET 4
PART A: BOTANY
I. Answer any 3 questions from 1 – 5. Each carries 1 score. (3 x 1 = 3)
b. Secondary consumer
Cry I Ac: Control cotton bollworm
……………….: Control corn borer
The post fertilization events in angiosperms.
Zygote : Embryo
Ovule : ………………
Ovary : ………………
Ovary: Fruit
II. Answer any 9 questions from 6 – 16. Each carries 2 scores. (9 x 2 = 18)
'-' detrimental interaction
'0' neutral interaction
Observe the interactions of populations of 3 species as shown in the table. Name the interactions between:
a. Species x and species y in case 1
b. Species y and species z in case 2
c. Species x and species z in case 3
d. Species y and species z in case 1
Population interactions:
a. Mutualism
b. Parasitism/Predation
c. Competition
d. Commensalism
Post-fertilization events in sexual reproduction include:
• Endosperm development: Primary endosperm cell divides repeatedly to form a triploid endosperm tissue.
• Embryogeny: The zygote develops into an embryo.
• Seed and Fruit formation: The ovules develop into seeds and the ovary develops into a fruit.
A= Motor
B= Foam braker
C= Flat bladed impeller
D= Culture broth.
Somatic hybridization is the fusion of protoplasts from two different varieties of plants with desirable characters to get hybrid protoplasts. It is grown to form a new plant called somatic hybrids.
Protoplasts can be isolated after digesting the cell walls of plant cells.
E.g. Tomato protoplast + Potato protoplast → pomato.
Emasculation and Bagging.
• Emasculation: Removal of anthers from the bisexual flower bud of female parent before the anther dehisces.
• Bagging: Here, emasculated flowers are covered with a bag to prevent contamination of its stigma with unwanted pollen.
a. ori
b. rop
a) Ori (Origin of Replication) is a specific sequence in the DNA where replication begins. Any piece of DNA linked to this sequence can replicate within host cells.
b) rop: Codes for the proteins involved in the replication of plasmid.
Yes. Biotechnology has important application in the field of Molecular Diagnosis. For example,
a. Polymerase Chain Reaction (PCR): It is used to detect HIV in suspected patients, gene mutations in suspected cancer patients etc.
b. ELISA (Enzyme Linked Immuno-Sorbent Assay): It is used to detect infection by pathogen or the antibodies synthesized against the pathogen.
b) Write the equation to describe this.
a) A population with limited resources shows initially a lag phase, phases of acceleration & deceleration and finally an asymptote. This type of population growth is called Verhulst-Pearl Logistic Growth.
b)
It is a process in which fitness of one species (r value) is significantly lower in presence of another species. Here, both species are harmed (-).
E.g., Flamingoes & fishes in some shallow South American lakes compete for zooplankton.
(a) Trophic level
(b) Food web.
(a) Trophic Level: It refers to the position an organism in a food chain.
(b) Food Web: It is a complex network of interconnecting food chains that shows the feeding relationships.
Fragmentation: It is the breakdown of detritus into smaller particles by detritivores (e.g. earthworm).
Leaching: It is the process in which water soluble inorganic nutrients go down into soil horizon and precipitate as unavailable salts.
III. Answer any 3 questions from 17 – 20. Each carries 3 scores. (3 x 3 = 9)
b. Explain how parasitism differs from predation.
c. Give the significance of species interaction.
(a) i. Mutualism
ii. Competition
iii. Commensalism
iv. Amensalism
(b) Predation: A predator kills and consumes its prey.
Parasitism: A parasite lives off a host, causing harm but not immediate death.
(c) It is essential to form a biological community, for energy flow and nutrient cycling.
(a)
It is a diagrammatic representation of the mature embryo sac.
A= Antipodals
B= Polar nuclei
C= Egg
D= Synergids
E= Filiform apparatus
3’ – CTTAAG – 5’
a. Give salient features of this sequence.
b. Write name of enzymes which recognize such sequences.
c. Elaborate importance of this enzyme in Genetic engineering.
(a) Palindromic sequence
(b) EcoRI Restriction endonuclease
(c) This enzyme cuts at specific nucleotide sequence to get sticky ends. The same restriction enzyme is used to cut both foreign DNA and cloning vector. This helps to create recombinant DNA.
PART B: ZOOLOGY
I. Answer any 3 questions from 1 – 5. Each carries 1 score. (3 x 1 = 3)
a. Gastrula
b. Morula
c. Zygote
d. Blastocyst
a. AAA
b. AUG
c. GUA
d. UGA
a. HIV
b. Haemophilia
c. Genital warts
d. Hepatitis B
a. MALT
b. NACO
b. National AIDS Control Organisation.
II. Answer any 9 questions from 6 – 16. Each carries 2 scores. (9 x 2 = 18)
a) Expand HCG.
b) What does the presence of HCG indicate?
c) Which is the source of HCG?
a) Human Chorionic Gonadotropin
b) She is pregnant.
c) Placenta.
a. Suggest the contraceptive action of CuT.
b. Name the hormone releasing IUDs.
a) Cu ions suppress motility and fertilising capacity of sperms.
b) Progestasert, LNG-20.
a. Name the test used.
b. Procedure of the test is given below. Complete it.
i. Isolation of DNA
ii. DNA is cut using restriction endonuclease
iii. …………………
iv. …………………
v. Hybridisation using VNTR probe
vi. ………………….
a) DNA fingerprinting.
b) iii. Separation of DNA fragments by gel electrophoresis.
iv. Transfer of separated DNA fragments into nitrocellulose or nylon membrane.
vi. Detection of DNA using autoradiography.
b. How many histone molecules are present in the histone core?
c. Distinguish Euchromatin and Heterochromatin.
a) Nucleosome.
b) 8
c) Euchromatin: Loosely packed, light stained and transcriptionally active chromatin.
Heterochromatin: Densely packed, dark stained and transcriptionally inactive chromatin.
Darwinian variations: These are minor, slow and directional. It results in gradual evolution.
Mutational variations: These are sudden, random and directional. Speciation is by saltation.
a. Double helical model of DNA was proposed by Jacob and Monod.
b. Sugar present in RNA is Ribose.
c. Introns are the coding sequences of a eukaryotic gene.
d. DNA replication occurs by semi-conservative method.
a) False. Double helical model of DNA was proposed by Watson and Crick.
b) True.
c) False. Exons are the coding sequences of a eukaryotic gene.
d) True.
b. State that theory and name the scientists who proposed it.
a) Theory of Chemical Evolution.
b) It states that the first form of life was originated from non-living inorganic & organic molecules.
This theory was proposed by Oparin and Haldane.
“Allele frequencies in a population are stable and is constant from generation to generation.”
a. Name the principle mentioned here.
b. Mention any three factors that affect the equilibrium.
a) Hardy-Weinberg Principle.
b) Gene migration, genetic drift, Mutation, Natural selection etc.
a. How do the bacteria respond to the above situation at genetic level?
b. If lactose is removed from the medium, what will happen?
a) In E. coli, lac operon will be switched on. Lactose (inducer) binds with repressor protein. So repressor protein cannot bind to operator region. It induces the RNA polymerase to bind with promoter. Then transcription starts.
b) If lactose is removed, lac operon remains switched off. The regulator gene synthesizes mRNA to produce repressor protein. This protein binds to the operator region and blocks RNA polymerase movement. So the structural genes are not expressed.
(b) A person has earlier symptoms of STDs. What will happen if he/she does not consult a doctor? (Mention any two consequences).
a) Sexually Transmitted Diseases.
b) Pelvic Inflammatory Diseases (PID), Infertility, Ectopic Pregnancy, abortions, still births, cancer of the reproductive tract etc.
III. Answer any 3 questions from 1 – 20. Each carries 3 scores. (3 x 3 = 9)
a. What are these?
b. Mention any 4 ill-effects of alcoholism.
a) Cannabinoids are a group of drugs obtained from Cannabis sativa. E.g., marijuana, hashish, ganja.
b) • Reckless behaviour, vandalism and violence.
• Coma and death.
• Damage of nervous system and liver cirrhosis.
• Mental and social distress to family and friends.
b. Name the enzyme involved in this process.
c. Explain the three major steps in this process.
a) Transcription.
b) RNA polymerase.
c) Initiation, Elongation, Termination.
• Initiation: Here, RNA polymerase binds at the promoter site of DNA. An initiation factor (ฯ factor) present in RNA polymerase initiates the RNA synthesis.
• Elongation: RNA chain is synthesized in 5’-3’ direction. Ribonucleoside triphosphates are added.
• Termination: A termination factor (ฯ factor) binds to the RNA polymerase and terminates the transcription.
Three arguments of the reasons for biodiversity conservation:
a. Narrowly utilitarian arguments: Human derive economic benefits from nature.
b. Broadly utilitarian arguments: Biodiversity has ecosystem services. E.g. production of O2, Pollination, Aesthetic pleasures.
c. Ethical arguments: Every species has an intrinsic value. We have to care them.
(b) Categorise the given birth control methods into two groups under proper headings.
a) User-friendly, easily available, effective and reversible, no or least side-effects etc.
(b)
