KCET 2023 Biology Question Paper (Available): Download Set C1 Question Paper with Answer Key PDF

The clitoris is a small, sensitive organ located at the top of the vulva, at the junction of the labia minora, above the urethral opening. It is a highly sensitive part of the female reproductive system and plays a significant role in sexual pleasure. The clitoris consists of erectile tissue and has a high concentration of nerve endings.

Hymen (B): The hymen is a thin membrane that partially covers the vaginal opening in some females. It is often mistakenly associated with virginity, but its presence or absence can vary greatly and is not a reliable indicator of sexual experience.

Vagina (C): The vagina is the muscular canal that leads from the uterus to the external genitalia. It serves as the passage for menstrual blood, sexual intercourse, and childbirth, but it is not the finger-like structure described in the question.

Mons pubis (D): The mons pubis is a rounded, fatty area of tissue located above the pubic bone and covered with pubic hair after puberty. It is not the finger-like structure mentioned.

Thus, the correct answer is (A) Clitoris. Quick Tip: The clitoris is the primary organ responsible for sexual pleasure in females, unlike other parts such as the hymen or vagina, which serve different functions.

Statement 1: The presence or absence of the hymen is not a reliable indicator of virginity or sexual experience. This is absolutely true because the hymen can be stretched or torn due to various non-sexual activities, such as sports, tampon use, or medical procedures. Virginity cannot be determined solely by the condition of the hymen.

Statement 2: The sex of the foetus is determined by the father and not by the mother. This is correct because the sex of the child is determined by the type of sperm cell that fertilizes the egg. The mother always contributes an X chromosome, but the father can contribute either an X (resulting in a female) or a Y (resulting in a male). Thus, the father determines the sex of the foetus.

Since both statements are correct, the answer is (D). Quick Tip: Remember, the sex of the child is determined by the sperm's X or Y chromosome, and the hymen's condition is not a reliable indicator of sexual experience.

The male reproductive system includes several ducts that transport sperm. The sequence is as follows:

Rete testis: The rete testis is a network of tubules located in the testes. It collects sperm from the seminiferous tubules and transports it to the vasa efferentia.

Vasa efferentia: The vasa efferentia are a series of ducts that transport sperm from the rete testis to the epididymis.

Epididymis: The epididymis is a coiled tube located on the surface of the testes where sperm mature and are stored.

Vas deferens: The vas deferens is the duct that carries mature sperm from the epididymis to the urethra during ejaculation.

Thus, the correct answer is (C). Quick Tip: The male accessory ducts are vital for the transport, maturation, and storage of sperm before ejaculation.

Understand the functions of parts of human sperm

Head contains the haploid nucleus (Answer: s).

Acrosome is filled with enzymes that help in fertilization (Answer: p).

Middle piece contains mitochondria, providing energy for sperm motility (Answer: q).

Tail is responsible for sperm motility (Answer: r).

Thus, the correct pairing is (B). Quick Tip: The acrosome in sperm contains enzymes crucial for penetrating the egg during fertilization, while the tail aids in motility.

Step 1: Understand the process of fertilization in plants

During fertilization, the egg cell fuses with one male gamete to form the zygote, which becomes the embryo. The central cell, which has two polar nuclei, fuses with another male gamete to form the primary endosperm nucleus, which develops into the endosperm (food reserve for the developing embryo).

Step 2: Eliminate other options

Antipodals and synergids: These cells do not directly participate in fertilization; they are involved in the process but do not change ploidy after fertilization.

Synergids and egg cell: Only the egg cell changes its ploidy, but synergids help in guiding the pollen tube.

Thus, the correct answer is (C). Quick Tip: The egg cell and central cell are the two cells in the embryo sac that change ploidy after fertilization, forming the zygote and the primary endosperm nucleus, respectively.

ZIFT stands for Zygote Intra Fallopian Transfer. In this procedure, the zygote (fertilized egg) is transferred into the fallopian tube for implantation.

Step 2: Eliminate other options

Zygote Inter Fallopian Tube and Zygote Inter Fallopian Transfer are not correct terms.

Zygote Intra Fallopian Tube is not the correct abbreviation for ZIFT.

Thus, the correct answer is (B). Quick Tip: ZIFT involves transferring a fertilized egg directly into the fallopian tube, while IVF involves placing the fertilized egg into the uterus.

The LNG-20 is a hormone-releasing intrauterine device (IUD) that releases levonorgestrel, a hormone that prevents pregnancy.

Step 2: Eliminate other options

Lippes loop: A non-hormonal IUD.

Implant: A hormonal contraceptive but not an IUD.

Multiload 375: A non-hormonal IUD.

Thus, the correct answer is (B). Quick Tip: Hormone-releasing IUDs, like LNG-20, release small amounts of hormone over time to prevent pregnancy.

Medical Termination of Pregnancy (MTP) is considered safe within the first trimester of pregnancy (up to 12 weeks). After this, it can become riskier, and the procedure requires more complex care.

Step 2: Eliminate other options

180 days of pregnancy and 24 weeks of pregnancy go beyond the recommended safe limit for MTP.

Second trimester is generally safe but more complex and riskier compared to the first trimester.

Thus, the correct answer is (C). Quick Tip: MTP is most commonly performed during the first trimester due to lower risks of complications.

Statement (C) is correct. Female carriers of X-linked diseases like haemophilia can pass the defective gene to their sons, who will express the disease.

Step 2: Eliminate other options

Sickle cell anemia is a qualitative problem (not quantitative).

Thalassemia is a genetic disorder involving a qualitative problem.
Aneuploidy refers to a change in the number of chromosomes, not the whole set.

Thus, the correct answer is (C). Quick Tip: Haemophilia is an X-linked recessive disease, so female carriers can pass it to their sons.

Sturtevant is credited with the development of the first genetic map, using the concept of recombination frequencies to map genes.

Step 2: Eliminate other options

Mendel: The father of genetics, but he did not work on gene mapping.

Tschermak and Correns contributed to genetics but not gene mapping.

Thus, the correct answer is (A). Quick Tip: Sturtevant used recombination frequencies to create the first genetic map, which is essential to modern gene mapping.

Statement (1): Generally, a gene regulates a trait, but sometimes one gene has an effect on multiple traits. This is true. This is known as pleiotropy, where a single gene influences multiple traits.

Statement (2): The trait AB-blood group of man is regulated by one dominant allele and another recessive allele. Hence it is co-dominant. This is incorrect. AB blood group is a classic example of co-dominance, but both A and B alleles are dominant, not one dominant and the other recessive.

Thus, the correct answer is (B). Quick Tip: In co-dominance, both alleles contribute equally to the phenotype, like in the AB blood group.

Menstruation phase: Menses marks the shedding of the endometrium and the start of a new menstrual cycle. It involves bleeding and the regeneration of the endometrial lining.

Follicular phase: The L.H. (luteinizing hormone) surge occurs during the follicular phase, triggering ovulation.

Luteal phase: In the luteal phase, the corpus luteum develops and secretes progesterone to prepare the endometrium for implantation if fertilization occurs.

Thus, the correct answer is (A). Quick Tip: The L.H. surge during the follicular phase triggers ovulation, and progesterone supports endometrial regeneration in the luteal phase.

In a typical Mendelian monohybrid cross between a homozygous dominant (AA) and a homozygous recessive (aa) parent:

F1 generation: All offspring inherit one dominant allele from the homozygous dominant parent and one recessive allele from the homozygous recessive parent. As a result, all F1 individuals will express the dominant trait (heterozygous Aa).

F2 generation: If F1 individuals (heterozygous) are crossed, the recessive trait appears in about 25% of the F2 generation, following a 3:1 Mendelian ratio (dominant to recessive traits).

Thus, both the dominant and recessive traits appear in both the F1 and F2 generations, and the recessive trait appears in only F2 generation when the F1 individuals are crossed.

Therefore, the correct answer is (D). Quick Tip: In Mendelian inheritance, dominant traits appear in F1 and F2 generations, while recessive traits show up in F2 when F1 generation is crossed.

Histone proteins are positively charged because they are rich in basic amino acids, particularly arginine and lysine. These amino acids have positively charged side chains that interact with the negatively charged DNA, helping histones bind to DNA.

Step 2: Eliminate other options

Phenylalanine, Alanine, and Proline are neutral or non-polar amino acids and do not contribute to the positive charge on histones.

Thus, the correct answer is (D). Quick Tip: Histones are rich in basic amino acids like arginine and lysine, which contribute to their positive charge and enable them to bind DNA.

In eukaryotic genes, the coding sequences (exons) are interrupted by non-coding regions (introns). This phenomenon is known as split genes. During transcription, the entire gene is transcribed into RNA, including the introns. However, the introns are spliced out during RNA processing, leaving only the exons, which are then used to synthesize proteins.

Thus, the correct answer is (A). Quick Tip: In eukaryotic cells, exons are the coding regions of genes, while introns are non-coding sequences that are spliced out during RNA processing.

Francois Jacob and Jaques Monad were the scientists who elucidated the Lac operon model in E. coli bacteria. The Lac operon model explains how genes involved in lactose metabolism are regulated. The model involves the interaction between a repressor protein and the operator region of the operon, which regulates the transcription of genes in the presence or absence of lactose.

Thus, the correct answer is (D). Quick Tip: The Lac operon model explains gene regulation in bacteria and how operons respond to environmental changes, such as the presence of lactose.

Adaptive radiation refers to the rapid evolution of an ancestral species into a variety of forms that are adapted to different environments. Examples include Darwin’s finches (evolving to utilize different food sources), the long-necked giraffe (adapted to feeding on tall trees due to natural selection), and Australian marsupials (diversified to fill various ecological niches in Australia).

However, the long-necked giraffe is an example of natural selection and not adaptive radiation because it evolved from a common ancestor rather than diversifying rapidly into different species from one ancestor.

Thus, the correct answer is (C). Quick Tip: Adaptive radiation is the diversification of a species into different forms that occupy different ecological niches, not just natural selection of a single trait.

Given that the frequency of recessive individuals (\(q^2\)) is 0.16, we can find the frequency of the recessive allele (q) by taking the square root: \[ q^2 = 0.16 \quad \Rightarrow \quad q = \sqrt{0.16} = 0.4 \]
Since \(p + q = 1\), the frequency of the dominant allele (p) is: \[ p = 1 - 0.4 = 0.6 \]
The frequency of heterozygous individuals is given by: \[ 2pq = 2 \times 0.6 \times 0.4 = 0.48 \]

Thus, the correct answer is (D) 0.48. Quick Tip: Use Hardy-Weinberg equilibrium equations to calculate allele and genotype frequencies in populations: \( p^2 + 2pq + q^2 = 1 \).

In species with XY sex determination, males are the heterogametic sex, meaning they produce two types of gametes—one carrying the X chromosome and the other carrying the Y chromosome. This is in contrast to females, who produce only one type of gamete (XX). Hence, males produce dissimilar gametes, making them the heterogametic sex.

Thus, the correct answer is (A). Quick Tip: In species with XY sex determination, males produce two types of gametes (X and Y), while females produce only X-bearing gametes.

Pneumonia is an infection that causes inflammation in the lungs, often resulting in symptoms like difficulty in breathing, fever, chills, cough, and headache.

Step 2: Eliminate other options

Option (A): These are not typical symptoms of pneumonia.

Option (C): These symptoms are more related to other gastrointestinal issues, not pneumonia.

Option (D): These symptoms are more common in viral respiratory infections, not specific to pneumonia.

Thus, the correct answer is (B). Quick Tip: Pneumonia symptoms typically include fever, cough, and difficulty breathing.

The Pusa Sawani variety of Okra is resistant to Shoot \& Fruit borer, a common pest that affects Okra crops.

Step 2: Eliminate other options

Aphids and Jassids are also pests of Okra, but Pusa Sawani is specifically resistant to the Shoot \& Fruit borer.

Cereal leaf beetle is not typically a pest for Okra.

Thus, the correct answer is (A). Quick Tip: Pusa Sawani is a high-yielding variety of Okra resistant to common pests like Shoot \& Fruit borer.

Inbreeding refers to the mating of closely related individuals. While inbreeding can help eliminate undesirable traits, it generally increases homozygosity (not decreases), as the probability of inheriting the same allele from both parents increases.

Step 2: Eliminate other options

Option (A): Inbreeding can indeed help eliminate less desirable genes by focusing on more similar traits.

Option (C): Inbreeding helps establish pure lines, particularly in agriculture.

Option (D): Inbreeding may accumulate both superior and inferior genes, but it is not efficient for accumulating only superior genes.

Thus, the correct answer is (B). Quick Tip: Inbreeding often leads to increased homozygosity and can increase the likelihood of genetic defects if not managed properly.

The better yielding semi-dwarf varieties of rice developed in India are Jaya and Ratna. These varieties are known for their improved yield and semi-dwarf characteristics that prevent lodging, making them more suitable for intensive farming.

Step 2: Eliminate other options

Sonalika and Ratna are also semi-dwarf varieties, but Jaya and Ratna are the most widely recognized pair for their superior yield in India.

Kalyan Sona and Sonalika are notable for their characteristics, but Jaya and Ratna are better known for their combination of semi-dwarf stature and yield.

Thus, the correct answer is (B). Quick Tip: Jaya and Ratna are semi-dwarf rice varieties that yield well and are resistant to lodging, making them ideal for high-density farming.

In the MOET (Multiple Ovulation Embryo Transfer) technique, fertilized eggs are typically transferred to the surrogate mother at the 8-32 celled stage. This stage is ideal for embryo implantation as it is early enough to ensure successful development in the surrogate.

Step 2: Eliminate other options

The 2-4 celled stage is too early for embryo transfer as it is still in the very early stages of division.

The 16-32 celled stage is also a possibility, but the 8-32 celled stage is the more widely used time frame for successful transfer.

Thus, the correct answer is (A). Quick Tip: MOET involves transferring embryos at the 8-32 celled stage, which gives the best chances for successful pregnancy.

Roquefort cheese is a type of blue cheese that is ripened by fungi, specifically Penicillium roqueforti, which is a species of mold (fungus). This fungus is responsible for the characteristic blue veins and distinct flavor of Roquefort cheese.

Step 2: Eliminate other options

Virus: Viruses are not involved in the ripening of cheese.

Bacterium: While bacteria are involved in some cheeses, Roquefort is specifically ripened by fungi.

Yeast: Yeast is not responsible for the ripening of Roquefort cheese.

Thus, the correct answer is (D). Quick Tip: Roquefort cheese gets its distinct blue veins and flavor from Penicillium roqueforti, a type of fungus.

BOD (Biochemical Oxygen Demand) is a measure of the oxygen required by microorganisms to break down organic material in water. A high BOD value indicates a high level of pollution.

A BOD value of 6 mg/L indicates that the water is highly polluted, as higher BOD values signify more contamination from organic matter.

Step 2: Eliminate other options

Lower BOD values, such as 0.6 mg/L, 0.16 mg/L, and 0.06 mg/L, suggest better water quality with lower pollution levels.

Thus, the correct answer is (A). Quick Tip: A high BOD value (above 5 mg/L) indicates significant pollution and poor water quality, as it reflects higher microbial activity breaking down organic matter.

Haemozoin is a toxic substance released during the digestion of hemoglobin by the Plasmodium parasite, which causes Malaria. This substance is responsible for the characteristic symptoms of fever and chills in malaria.

Step 2: Eliminate other options

Dengue, Typhoid, and Pneumonia do not involve the release of haemozoin. These diseases have different mechanisms and pathogens that do not include this substance.

Thus, the correct answer is (A). Quick Tip: Haemozoin is released during the breakdown of red blood cells by the malaria parasite, leading to fever and chills as a symptom of infection.

Biolistics (A): Also known as particle bombardment, biolistics is a method of introducing DNA into cells by shooting microscopic particles coated with DNA into cells.

Micro-injection (B): In micro-injection, DNA is directly injected into the cell using a fine needle.

Use of disarmed pathogen vectors (C): This involves using modified viruses (which can no longer cause disease) to deliver DNA into cells.

Elution (D): Elution is a process used to remove a substance (such as DNA) from a solid medium by washing it out, not a method to make cells competent.

Thus, the correct answer is (D). Quick Tip: Biolistics, micro-injection, and disarmed pathogen vectors are methods used for making cells competent to take up DNA, whereas elution is a different process.

Statement (1): The first step in PCR (Polymerase Chain Reaction) is indeed heating, which separates the DNA strands to allow replication.

Statement (2): Genetic engineering has successfully been applied to both animals and plants, not just animals.

Statement (3): DNA from one organism can indeed bind to DNA from another organism, which is the basis of genetic engineering.

Statement (4): There are potential risks associated with r-DNA technology, such as unintended genetic changes or environmental impact.

Thus, the correct answer is (A). Quick Tip: PCR involves heating to separate DNA strands, and genetic engineering can work with both plants and animals.

Statement (A): The Kangaroo rat uses minimal water to remove waste products due to its highly efficient kidneys.

Statement (B): The Kangaroo rat is found in North American deserts, where it has adapted to the dry environment.

Statement (C): The Kangaroo rat does not eliminate dilute urine. Instead, it produces highly concentrated urine to conserve water in the desert.

Statement (D): The Kangaroo rat meets its water requirements through internal fat oxidation, a method of producing water through metabolism.

Thus, the correct answer is (C). Quick Tip: The Kangaroo rat has adapted to life in the desert by conserving water, producing concentrated urine, and using fat metabolism for hydration.

Aestivation (A): Aestivation is a period of dormancy in some animals during hot or dry conditions, not related to winter.

Diapause (B): Diapause is a state of dormancy in some insects and animals during unfavorable environmental conditions, but it is not specifically related to winter.

Migration (C): Migration is the movement of animals from one region to another, often for breeding or seasonal purposes, but not dormancy.

Hibernation (D): Hibernation is the process that bears undergo to survive the cold winter months. During this time, they enter a deep sleep-like state where their metabolic rate slows down, conserving energy.

Thus, the correct answer is (D). Quick Tip: Hibernation helps animals like bears survive during the cold winter months by reducing their metabolic rate and conserving energy.

1. Standing state refers to the mass of living material at a given time in an ecosystem (Answer: q).

2. Pioneer species are the species that invade a bare area first in the ecological succession (Answer: r).

3. Detritivores are organisms that feed on decaying organic matter and break down detritus into smaller particles (Answer: s).

4. Standing crop refers to the amount of nutrients available in the soil at a given time (Answer: p).

Thus, the correct matching is (A). Quick Tip: Pioneer species are the first to colonize bare areas, while detritivores help break down organic material, and standing crop refers to the mass of nutrients available.

Polymerase Chain Reaction (PCR) is a technique used to amplify small segments of DNA, making it easier to study or manipulate. PCR involves cycles of DNA denaturation, annealing of primers, and extension to generate millions of copies of a specific DNA segment.

Step 2: Eliminate other options

DNA digestion is done using restriction enzymes, not PCR.

DNA isolation involves extracting DNA from cells, not PCR.

DNA ligation involves joining DNA fragments, usually with ligases, not PCR.

Thus, the correct answer is (C). Quick Tip: PCR is a powerful tool for amplifying DNA sequences, allowing scientists to work with small amounts of DNA in research and diagnostics.

Toxic heavy metals, including lead, mercury, and cadmium, are commonly associated with industrial pollution. These metals have high densities compared to water. Typically, these metals have densities exceeding 5 g/cm³, with mercury being one of the heaviest at 13.53 g/cm³. Such metals can accumulate in aquatic ecosystems, leading to long-term environmental and health issues.

Thus, the correct answer is (B). Quick Tip: Heavy metals such as mercury, lead, and cadmium are denser than water and pose significant risks when they pollute water sources.

Step 1: Know the major greenhouse gases and their contributions. CO\textsubscript{2 is the leading contributor followed by methane, CFCs, and nitrous oxide.

Step 2: Match values. Option (B) correctly represents the relative contribution of each gas to global warming based on scientific consensus. Quick Tip: CO\textsubscript{2} contributes the most to global warming, followed by methane and CFCs.

The flower has 10 stamens, and each stamen has 2 bilobed anthers (which gives 2 lobes per anther).

Each anther contains 2 microsporangia (pollen sacs).

Each microsporangium contains 5 pollen mother cells (PMCs), and each PMC divides by meiosis to produce 4 pollen grains.


Thus, for each microsporangium, the number of pollen grains is: \[ 5 \, PMCs \times 4 \, pollen grains per PMC = 20 \, pollen grains per microsporangium \]

Since there are 2 microsporangia in each anther, and 2 anthers per stamen, the total number of pollen grains produced by the flower is: \[ 10 \, stamens \times 2 \, anthers per stamen \times 2 \, microsporangia per anther \times 20 \, pollen grains per microsporangium = 800 \, pollen grains \]

Thus, the correct answer is (A). Quick Tip: Each pollen mother cell produces 4 pollen grains. Multiply the number of stamens, anthers, and microsporangia to find the total pollen grain production.

During transcription, the enzyme DNA dependent RNA polymerase catalyzes the synthesis of mRNA using the DNA template strand. This enzyme always synthesizes RNA in the 5' \(\rightarrow\) 3' direction, meaning the RNA strand grows in the 5' to 3' direction, using the 3' to 5' strand of the DNA as the template.

Step 2: Eliminate other options

Option (A) is incorrect because RNA polymerase only works in one direction, 5' to 3'.

Option (C) talks about transferring nucleotides to mRNA but does not address the polymerization direction.

Option (D) is incorrect because RNA polymerase works in the 5' \(\rightarrow\) 3' direction, not 3' \(\rightarrow\) 5'.

Thus, the correct answer is (B). Quick Tip: RNA polymerase catalyzes transcription in the 5' \(\rightarrow\) 3' direction using the 3' \(\rightarrow\) 5' DNA strand as a template.

In David Tilman's long-term ecosystem experiments, it was found that plots with more species tend to have less variation in total biomass from year to year. This is because greater species diversity helps stabilize ecosystem functions, such as nutrient cycling and productivity, making the ecosystem more resilient to environmental fluctuations.

Step 2: Eliminate other options

Option (A): "Average variation" does not match the findings, as more species lead to less variation.

Option (C): "No variation" would not be realistic in an ecosystem with fluctuating conditions.

Option (D): "High variation" contradicts the findings that greater species diversity stabilizes the ecosystem.

Thus, the correct answer is (B). Quick Tip: Increased biodiversity generally leads to less variation in ecosystem functions over time due to enhanced stability.

Understanding the 10% energy transfer rule in the food chain.
It is commonly accepted that only about 10% of energy is transferred to the next trophic level. However, the statement in option (A) is incorrect as it implies that green plants capture only 10% of the solar energy, which is a simplification. In reality, green plants capture a much higher percentage of solar energy through photosynthesis, and only about 10% of this energy is passed on to the next trophic levels. Hence, option (A) is the incorrect statement. Quick Tip: In ecosystems, only about 10% of the energy is transferred to the next trophic level. Green plants capture more than 10% of solar energy, but this is used in photosynthesis, with only a fraction transferred up the food chain.

Identifying the correct pathogen and affected organ for each disease.

Filariasis is caused by a common roundworm and affects the lymphatic system, not the small intestine.

Ringworm is caused by a fungus and affects the skin, which matches option (B).

Dysentery is caused by protozoa, typically affecting the intestines, not the liver.

Typhoid is caused by bacteria and affects the intestines, not the lungs.


Therefore, the correct match is (B): Ringworm - Fungus - Skin. Quick Tip: Remember, diseases caused by fungi like ringworm typically affect the skin, while bacterial infections like typhoid primarily target the intestines. Protozoal infections such as dysentery affect the intestines as well, and roundworm-related diseases affect the lymphatic system.

1. Haemophilus influenzae causes pneumonia (Answer: r).

2. Entamoeba histolytica is responsible for amoebiasis (Answer: s).

3. Plasmodium falciparum causes malignant malaria (Answer: p).

4. Wuchereria bancrofti causes elephantiasis (Answer: q).

Thus, the correct matching is (D). Quick Tip: Haemophilus influenzae causes pneumonia, while Plasmodium falciparum causes malignant malaria. Entamoeba histolytica leads to amoebiasis, and Wuchereria bancrofti causes elephantiasis.

Identifying the correct tools and techniques for cloning.

The process of cloning a bacterial gene into animal cells typically involves:

Endonuclease (I) for cutting DNA at specific locations.
Ligase (II) for joining DNA fragments.
Microinjection (IV) for directly injecting DNA into animal cells.
Lysozyme (VI) for breaking down bacterial cell walls.
Electrophoresis (VIII) for separating DNA fragments.

Thus, the correct tools and techniques for cloning a bacterial gene into animal cells are I, II, IV, VI, and VIII. Quick Tip: For genetic engineering, tools like endonucleases and ligase are used for cutting and joining DNA. Microinjection is essential for directly introducing DNA into animal cells, while electrophoresis helps in DNA separation and analysis.

1. Bryophyta includes plants like Sphagnum (Answer: r).

2. Gymnosperm includes plants like Pinus (Answer: p).

3. Algae includes species like Ectocarpus (Answer: s).

4. Pteridophyta includes plants like Adiantum (Answer: q).

Thus, the correct matching is (D). Quick Tip: Bryophyta includes non-vascular plants, Gymnosperms are seed-producing plants, Algae are aquatic photosynthetic organisms, and Pteridophyta are ferns.

Flame cells in Platyhelminthes (flatworms) are specialized for osmoregulation and excretion. These cells help in the removal of excess water and waste products from the body. Flame cells are part of the protonephridia, which function to maintain osmotic balance and remove waste.

Step 2: Eliminate other options

Option (A): Flame cells are not involved in respiration. They are primarily responsible for osmoregulation and excretion.

Option (B): Although they help with osmoregulation, flame cells are not directly involved in circulation.

Option (C): While they are involved in osmoregulation, flame cells do not play a role in respiration.

Thus, the correct answer is (D). Quick Tip: Flame cells in Platyhelminthes function primarily in osmoregulation and excretion to maintain balance in their aquatic environments.

Step 1: Understand the floral formula for Solanaceae (Potato family)

The floral formula of plants in the potato family (Solanaceae) typically follows this pattern:

K(5): 5 sepals, fused or free (calyx)

C(5): 5 petals, fused or free (corolla)

A5: 5 stamens (androecium)

G2: 2 fused carpels (gynoecium)


Step 2: Match the formula

Option (A): 9+1 stamens (incorrect for potato family)

Option (B): 5 sepals, 5 petals, 5 stamens, 2 fused carpels (correct for Solanaceae)

Option (C): 10 sepals, 10 petals, 10 stamens (incorrect for potato family)

Option (D): 3+3 petals, 3+3 stamens (incorrect for Solanaceae)


Therefore, the correct floral formula for the potato family is \( \oplus, K(5), C_5, A_5, G_2 \), which matches Option (B). Quick Tip: Solanaceae (Potato family) typically have a pentamerous floral structure: 5 sepals, 5 petals, 5 stamens, and 2 fused carpels.

When the vascular cambium is present between the xylem and phloem, and there is no clear distinction between the xylem and phloem as in "closed" vascular bundles, this results in an "open" vascular bundle. In open vascular bundles, the vascular cambium remains between the xylem and phloem, and the bundle does not have a complete protective layer. This is typical of dicotyledonous plants. Quick Tip: In plants, vascular bundles can be classified as open or closed based on the presence and arrangement of vascular cambium between the xylem and phloem.

The typhlosole is a longitudinal fold that runs along the inner surface of the earthworm's intestine. This fold increases the surface area available for nutrient absorption, much like villi in the human intestine. It enhances the efficiency of the digestive process, allowing the earthworm to absorb more nutrients from the decomposed organic matter it consumes.

While the other options might seem plausible, only the typhlosole's function directly impacts the absorption of nutrients, which is crucial for the earthworm's nutrition. Quick Tip: The Typhlosole is a unique feature in earthworms, enhancing their digestive efficiency by increasing the surface area of absorption in the intestine.

Homo sapiens belong to the order Primates, not Poales.

Triticum aestivum (wheat) belongs to the order Poales, not Sapindales.

Mangifera indica (mango) belongs to the order Sapindales, not Primata.

Musa domestica (banana) belongs to the order Zingiberales, not Diptera.


Therefore, the correct answer for this question is (D): Musa domestica : Diptera, but as per the classification provided, the question may need further review. Quick Tip: When studying organisms, it is important to familiarize yourself with taxonomic orders to accurately classify species. In this case, banana (Musa domestica) belongs to the Zingiberales order, not Diptera.

1. Collagen is a protein that is primarily involved in providing structure and strength to tissues, and it is not directly related to fighting infections, so it matches with Hormone (Answer: q).

2. Trypsin is an enzyme that helps break down proteins during digestion (Answer: r).

3. Insulin is a hormone produced by the pancreas to regulate blood sugar levels (Answer: p).

4. Antibodies are proteins involved in the immune response and help in fighting infectious agents (Answer: s).

Thus, the correct matching is (B).

Step-by-step matching:
Collagen: While it plays a structural role, it is mistakenly matched with Hormone.

Trypsin: This is the enzyme responsible for protein digestion (Answer: r).

Insulin: A hormone that regulates blood glucose (Answer: p).

Antibodies: These proteins help in fighting infections (Answer: s).

Thus, the correct answer is (B). Quick Tip: Collagen provides structural support in tissues, trypsin is an enzyme that aids in digestion, insulin regulates blood sugar, and antibodies protect against infections.

During meiosis, homologous chromosomes pair up in a process called synapsis. The complex formed by a pair of synapsed homologous chromosomes is known as a bivalent. This structure is crucial for genetic recombination and is observed during prophase I of meiosis. Each bivalent consists of two chromosomes, each with two chromatids, making a total of four chromatids.

Step-by-step explanation:

1. Bivalent: The term "bivalent" refers to the pair of homologous chromosomes that are physically connected during meiosis. This pairing allows for genetic recombination and is essential for the proper segregation of chromosomes.

2. Pentavalent: This refers to a structure involving five components, which is not observed in meiosis for homologous chromosomes.

3. Univalent: A univalent refers to a single chromosome or chromatid that is not paired with its homolog during meiosis.

4. Trivalent: A trivalent involves three chromosomes or chromatids, which is also not the case for synapsed homologous chromosomes.

Thus, the correct answer is (A). Quick Tip: During meiosis, homologous chromosomes form a bivalent in prophase I, which is essential for the exchange of genetic material (crossing over) between chromosomes.

1. Hypertonic: A hypertonic solution has a higher concentration of solutes compared to the cell sap. This results in water moving out of the cell (Answer: q).

2. Capillarity: Capillarity refers to the ability of water to rise in narrow tubes due to cohesion and adhesion (Answer: p).

3. Symport: Symport refers to the process where two molecules move in the same direction across the membrane (Answer: p).

4. Guttation: Guttation is the loss of water from plants in the form of droplets, typically from the leaf edges (Answer: r).

Thus, the correct matching is (C).

Step-by-step matching:
Hypertonic: Refers to an external solution that is more concentrated than the cell sap, leading to water loss from the cell (Answer: q).

Capillarity: The ability of water to rise in narrow tubes, such as in plant xylem (Answer: p).

Symport: Involves the simultaneous movement of two molecules in the same direction across the membrane (Answer: p).

Guttation: The release of water in droplets from plants (Answer: r).

Thus, the correct answer is (C). Quick Tip: Symport involves the movement of two molecules in the same direction across a membrane, while capillarity is responsible for water rising in narrow tubes, and guttation is the loss of water from plants in droplets.

Manganese toxicity can lead to the deficiency of other essential nutrients, including iron, magnesium, and calcium. This happens because excessive manganese can interfere with the absorption and utilization of these nutrients in plants. When the concentration of manganese is too high, it can block the uptake of other critical micronutrients, causing deficiency symptoms. Quick Tip: Excessive manganese in plants can result in nutrient imbalances, especially with iron, magnesium, and calcium. It is essential to maintain proper micronutrient levels for healthy plant growth.

Cardiac output is a measure of the amount of blood the heart pumps per minute. It is calculated using the formula:
\[ Cardiac Output = Stroke Volume \times Heart Rate \]

For an adult human, we are given that the stroke volume is 70 mL (0.070 L), and the typical heart rate is about 70 beats per minute. So, the cardiac output per minute is:
\[ Cardiac Output per minute = 0.070 \, L \times 70 = 4.9 \, L/min \]

To calculate the cardiac output in one hour, multiply by 60:
\[ Cardiac Output per hour = 4.9 \, L/min \times 60 = 302.4 \, L/hour \]

Therefore, the cardiac output in one hour is 302.4 Lit/hour. Quick Tip: Cardiac output is the product of stroke volume and heart rate, and is crucial for assessing the heart's efficiency in delivering blood throughout the body.

In Amoeba, the contractile vacuole plays a critical role in both osmoregulation and excretion. Osmoregulation refers to the process by which Amoeba regulates the water content within its cell to prevent swelling and bursting due to excess water intake. The contractile vacuole collects excess water from the cytoplasm and expels it out of the cell, maintaining osmotic balance.

Additionally, it helps in the excretion of metabolic waste products from the cell, ensuring the cell's internal environment remains stable and healthy. This function is vital for the Amoeba’s survival in freshwater environments where water tends to enter the cell due to osmosis. Quick Tip: The contractile vacuole is a key organelle in freshwater protozoa like Amoeba, helping maintain osmotic balance by expelling excess water and waste products.

Atrial Natriuretic Factor (ANF) is a hormone produced by the heart's atrial cells. Its primary function is to reduce blood volume and blood pressure. ANF acts by inhibiting the Renin-Angiotensin system, which usually promotes vasoconstriction (narrowing of blood vessels) and sodium retention, both of which increase blood pressure. By inhibiting this system, ANF promotes vasodilation and natriuresis (excretion of sodium), which helps lower blood pressure. Therefore, ANF does not induce hypertension but rather counters it by blocking the Renin-Angiotensin system. Quick Tip: ANF is a hormone that plays an important role in regulating blood pressure by inhibiting the Renin-Angiotensin system, causing vasodilation and reducing blood volume.

When sound waves enter the ear, they cause the ear drum (tympanic membrane) to vibrate. These vibrations are transmitted via the three small bones in the middle ear (ossicles: malleus, incus, and stapes) to the oval window, a membrane-covered opening leading to the cochlea in the inner ear. The oval window transfers the vibrations into the fluid-filled cochlea, where they are converted into nerve impulses by hair cells. These impulses are sent to the brain via the auditory nerve. Therefore, the oval window is the correct answer, as it serves as the connection between the ossicles and the cochlea. Quick Tip: The oval window transmits the mechanical vibrations from the ear ossicles into the cochlea, enabling the conversion of sound vibrations into electrical signals.

Bamboo species are known for their unusual flowering patterns. Most species of bamboo flower only once in their lifetime. This phenomenon, called "gregarious flowering," occurs after several decades of vegetative growth. After flowering, the plant produces seeds, and the parent plant typically dies. However, some species of bamboo flower at different intervals, such as every 50 to 100 years. Despite this, the most widely recognized characteristic of bamboo is that it flowers only once in its lifetime. Quick Tip: Bamboo species are known for flowering once in their lifetime, and after flowering, they often die. This unique phenomenon occurs after several decades of vegetative growth.

Bryophyllum is a plant that is capable of vegetative reproduction through adventitious buds, which are buds that form in unusual locations. In Bryophyllum, the adventitious buds typically arise from the notches along the margins of the leaves. These buds can grow into new plants when they fall off the leaf and root in the soil. This form of reproduction is an example of asexual reproduction, where new plants are formed from vegetative parts of the parent plant. Quick Tip: In Bryophyllum, vegetative reproduction occurs through the formation of adventitious buds at the notches on the leaf margins. This allows the plant to reproduce asexually, ensuring the survival of the species.

The primary endosperm nucleus is formed by the fusion of two polar nuclei and one male gamete. This results in a triploid endosperm nucleus, which is crucial for the development of the endosperm that nourishes the developing embryo.

Thus, the correct answer is (B). Quick Tip: The fusion of two polar nuclei and one male gamete during fertilization in angiosperms forms the primary endosperm nucleus.

The conducting system of the human heart is responsible for coordinating the electrical impulses that regulate the heartbeat. The correct order of structures involved in this system is:

p (SAN): The Sinoatrial Node (SAN), located in the right atrium, initiates the electrical impulses that stimulate heartbeats.
q (AVN): The Atrioventricular Node (AVN) receives the impulses from the SAN and delays them to ensure the atria contract before the ventricles.

r (Bundle of His): The Bundle of His is responsible for transmitting the impulses down the interventricular septum towards the ventricles.

s (Interventricular septum): The Interventricular septum is the wall separating the left and right ventricles, through which the electrical impulses travel after passing through the Bundle of His.

Thus, the correct answer is (B).

Step-by-step matching:
SAN (Sinoatrial Node) initiates the electrical impulse (Answer: SAN).

AVN (Atrioventricular Node) delays the impulse (Answer: AVN).

Bundle of His transmits the impulse to the ventricles (Answer: Bundle of His).

Interventricular septum transmits the impulses to the ventricles (Answer: Interventricular septum).

Thus, the correct answer is (B). Quick Tip: The SAN generates the heart's electrical impulses, which are then transmitted through the AVN, Bundle of His, and Interventricular septum to coordinate the heartbeat.