Biology Quiz on Gametes and Autogamy

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Questions and Answers

In majority of sexually reproducing organisms, the gametes are:

homogametes

hemigametes

heterogametes (correct)

isogametes

Autogamy is best described as:

the transfer of pollen grains from the anther to the stigma of the same flower (correct)

the maturation of anther and stigma at different times

the transfer of pollen grains from the anther to the stigma of a different flower

the dehiscence of anther and release of pollen grains

Which type of questions are included in Section B of the paper?

Multiple choice questions of one mark

Long answer type questions of five marks

Case-based short answer type questions

Short answer type I questions of two marks (correct)

The maximum marks for the biology sample paper is:

70 Signup and view all the answers

How many total questions are there in the sample paper?

27 Signup and view all the answers

In which section does not have any overall choice?

All sections Signup and view all the answers

Which section contains case-based short answer type questions?

Section D Signup and view all the answers

How many long answer type questions are in Section E?

3 Signup and view all the answers

What condition arises when a person has two copies of the HbS allele?

Sickle-cell anaemia Signup and view all the answers

What is the expected probability of having a normal child when a homozygous female for the HbS allele has children with a heterozygous male?

0% Signup and view all the answers

In the context of inheritance, which type of disorder is haemophilia classified as?

Sex-linked recessive Signup and view all the answers

What might explain the low population of mosses and ferns in biodiversity?

Extreme environmental conditions Signup and view all the answers

Which group of plants is generally considered the most advanced based on biodiversity classifications?

Angiosperms Signup and view all the answers

What is the main environmental consequence of excessive use of urea and phosphate fertilizers in crops?

Eutrophication of water bodies Signup and view all the answers

What effect does the spraying of DDT have on aquatic ecosystems?

Reduces fish populations Signup and view all the answers

What can be concluded about the pedigree chart showing a trait absent in parents but present in the next generation?

The trait is recessive. Signup and view all the answers

Why might couples consider sterilization as a last contraceptive option?

It is irreversible and may be regretted later. Signup and view all the answers

What distinguishes sticky ends in DNA strands from blunt ends?

Sticky ends allow for easier ligation of DNA strands. Signup and view all the answers

What could explain the lack of DNA bands in an ethidium bromide-stained agarose gel?

DNA was lost during handling. Signup and view all the answers

What is the role of the placenta in the relationship between the fetus and the maternal body?

It facilitates gas exchange and waste removal. Signup and view all the answers

Why is only a small percentage of genetic information transcribed into functional RNA in mammalian cells?

Most DNA is non-coding and does not produce proteins. Signup and view all the answers

What factor increases the risk of a haemophilic child in a non-haemophilic couple?

Both parents carrier of a recessive allele Signup and view all the answers

Which of the following represents a genotype of a haemophilic child?

XhXh Signup and view all the answers

How many chromosomes would be present in the gametes if a plant's meiocyte has 24 chromosomes?

12 Signup and view all the answers

What part of the flower develops into the fruit?

Ovaries Signup and view all the answers

Which organ is primarily responsible for the ovulation process in females?

Ovary Signup and view all the answers

What is the causative agent of AIDS?

Virus Signup and view all the answers

Which symptom is NOT associated with amoebic dysentery caused by Entamoeba histolytica?

Skin rash Signup and view all the answers

What is the primary mode of transmission for Entamoeba histolytica?

Contaminated water Signup and view all the answers

What is one of the measures taken by the Indian government to control vehicular air pollution?

Introduction of CNG Signup and view all the answers

What is the primary reason for new species evolving at a faster rate?

Increasing anthropogenic actions Signup and view all the answers

In an ecological pyramid, what does the base typically represent?

Producers Signup and view all the answers

Which restriction enzyme would most likely be used to introduce a foreign gene into the ampR region of pBR322?

Eco RI Signup and view all the answers

What is the primary reason activated sludge should settle quickly?

To be rapidly pumped back from sedimentation tank to aeration tank Signup and view all the answers

What is the causative agent of typhoid?

Salmonella typhi Signup and view all the answers

Which modes of transmission for HIV are correct?

Transfusion of contaminated blood and sexual contact with infected individuals Signup and view all the answers

What is the function of β-galactosidase in E.coli?

To break down lactose Signup and view all the answers

What may prevent a bacterial cell from producing a desired human protein after transformation?

The human gene may contain introns which bacteria cannot process Signup and view all the answers

What are the symptoms of pneumonia?

Cough and difficulty breathing Signup and view all the answers

Which of the following describes Organism A and B as conformers or regulators?

Organism A- Conformer; Organism B- Regulator Signup and view all the answers

What concept is illustrated by the connection between different trophic levels in an ecosystem?

Food web Signup and view all the answers

What is the role of an antibiotic resistance gene in a vector?

Assists in the selection of recombinant cells Signup and view all the answers

What is the outcome if a bacterial cell incorporates a human gene with introns?

The expression will fail due to intron presence Signup and view all the answers

What method is ineffective for preventing HIV transmission?

Shaking hands with HIV-infected persons Signup and view all the answers

Which scenario depicts a typical response of conformers?

Adapting their physiology closely to variations in environmental temperature Signup and view all the answers

Study Notes

General Instructions

Biology Class XII (2019-20)
Sample Paper-1
27 questions, 5 sections
All questions are compulsory
Section A: multiple choice (1 mark each, Q1-5)
Section B: short answer type I (2 marks each, Q6-12)
Section C: short answer type II (3 marks each, Q13-21)
Section D: case-based short answer (3 marks each, Q22-24)
Section E: long answer type (5 marks each, Q25-27)
No overall choice, internal choices provided in some questions

Section A - Multiple Choice Questions

Q1: Gametes in most sexually reproducing organisms are heterogametes (different)
Autogamy: Pollen transfer within the same flower
Activated sludge: Quickly settling for efficient water purification, absorbing pollutants.
AIDS transmission: HIV transmitted via blood transfusion, sexual contact, and infected blood
Q3(cont.): • (ii) & (iv) are incorrect modes of transmission. • (i) and (iii) are correct HIV transmission modes.

Section B - Short Answer Type I

Q6: Lake fish mortality possibly due to urea/fertilizers, pesticide use (DDT), phytoplankton decline. • Three reasons explain the fish mortality in the lake. • Phytoplankton decline and increase in pollutants could lead to fish mortality.
Q7: Pedigree indicates trait is inherited. The trait is inherited in a sex-linked dominant pattern
Q8: Sterilization is the last resort due to the risk of side effects or irreversibility.
Q9: Haploid organisms produce gametes by mitosis, yet meiosis still occurs.
Q10: Sticky ends form on DNA strands during restriction enzyme cuts, making them useful in genetic engineering. They are called sticky ends due to the single-stranded overhangs.
Q11: Only about 1% of DNA is transcribed because of gene regulation mechanisms. Mechanisms control which genes are expressed.
Q12: Thymus removal in a 15-year-old affects their immune system causing defects in T-cell immunity.

Section C - Short Answer Type II

Q13: Bacterial colonies with cloning vector A are colorless, while those with cloning vector B are blue due to the chromogenic substrate. This is used to identify recombinant cells. • DNA is not visible in the agarose gel because of electrophoresis issues.
Q14: Haemophilia is an X-linked recessive disorder. Doctors suspect haemophilia in a child because one parent carries the disease's recessive allele. • Possible genotype for non-haemophilic couple = X^HX^h and X^HY
Q15: Conditions for diploid cell development= suitable environment and proper nutrition • Chromosomes in a plant meiocyte is 24, gamete has 12 and zygote has 24
Q16: Parts of the flower are labeled, followed by a discussion on seed and fruit development in relation to the flower parts and their roles. (specific parts)
Q17: Column I contains female organs and column II contains their functions such as ovulation, fertilization. • Acrosome and sperm tails' function in reproduction.
Q18: AIDS meaning, causes and the details of the causative agent, How AIDS is transmitted, • Ankit's colleague's perspective is not valid as it's based on misconceptions.

Section D - Case Based Short Answer Type

Q19: Entamoeba histolytica transmission, Symptoms and prevention measures
Q20: Indian government's measures to control vehicular air pollution and their environmental effects
Q21: New species evolution and anthropogenic impact on the evolutionary process via examples, illustrating a short timescale.
Q22: Ecological pyramid types (numbers, biomass, energy), base (producers) and apex (top consumers) meanings in ecological systems and specific examples.
Q23: Detailed analysis of the given image to provide suitable answers based on the provided figure. Specific labelling and specific descriptions of the enzymes.
Q24: Molecule functioning in gene regulation (molecule "X", synthesised by 'i' gene), inactivation, structural gene, and transcription stopping time. Discussion of the details of the labelled parts in the diagram.

Section E - Long Answer Type

Q25: Viral and Bacterial disease details including causative agents, symptoms, and infection methods
Q26: • Single point mutation causing sickle-cell anaemia (Hbs). • Work out a cross; probability of normal/diseased child; Discuss the advantage of heterozygous condition. • Detailed analysis of the specific cases involving inheritance and advantages of both conditions (sickle-cell and haemophilia)
Q27: Biodiversity of plants, analysis of the given figure (Endangered and other plant groups) and explanation of the specific and detailed explanations of fungi and their conservation, biodiversity and conservation discussion.

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Description

Test your knowledge on gametes in sexually reproducing organisms and understand the concept of autogamy. This quiz will challenge your grasp of key reproductive processes in biology. Perfect for students studying biology or preparing for exams!