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Right Answe Is D
The oestrous cycle refers to a series of recurring physiological events in most mammalian therian females. These changes are induced by reproductive hormones formed in their body. The oestrous cycle is observed in non-primate vertebrates such as cows, deer, dogs, lions, and so on.

Right Answe Is B
Bamboo possesses an unusual flowering phenomenon in that it flowers only once in its lifetime. It blooms after 60-130 years and reaches its maximum life expectancy at that point. However, plants like mango, maize and litchi flower more than one time in their lifetime.

Right Answe Is D
Internal fertilisation is the fusion of an egg and a sperm cell within the female body during sexual reproduction. It is found in higher animals such as reptiles, birds, mammals, and terrestrial fungi, as well as in most plants such as bryophytes, pteridophytes, gymnosperms, and angiosperms.

Right Answe Is A
During microsporogenesis, a pollen mother cell divides to form a microspore tetrad which is a group of four microspores attached together. Meiotic division in the pollen mother cell leads to the formation of this microspore tetrad.

Right Answe Is C
The anther is a globular structure present on the free end of the stamen. Pollen grains are produced inside the pollen sacs of the anther. It has microsporangia which are enveloped with various cellular layers. Tapetum is the innermost layer which is surrounded by middle layers. The endothecium layer is present outside the middle layers.

Right Answe Is A
The stamen is the male reproductive part of the flower which is attached to the thalamus or petals of the flower. Thalamus is the thickened end of the flower stalk on which the floral parts are grown to form a flower.
Petals are the bright-coloured leafy appendages of flowers which help to attract pollinators. In a typical flower, the whorl of stamens is surrounded by the petal whorl. Thus, stamens are sometimes attached to petals or grown directly on the thalamus.

Right Answe Is C
The outer thick wall of a pollen grain is referred to as exine, and the inner thin wall is referred to as intine. The hard outer layer, known as the exine, is composed of sporopollenin, one of the hardest and most resistant organic materials known.

Right Answe Is A
In the testes, sperms are produced in coiled structures known as seminiferous tubules. The epididymis is a tubular organ located posterior to each testis that is responsible for sperm maturation.
The vas deferens is a muscular tube that connects the epididymis to the pelvic cavity. The prostate glands produce a thin, milky, alkaline fluid that aids in the neutralisation of the vas deferens’ acidic secretions.

Right Answe Is A
Leydig cells are endocrine cells found in the interstitial connective tissue surrounding seminiferous tubules. Interstitial spaces are the spaces between the seminiferous tubules in the testes. It is made up of small blood vessels and interstitial cells. These interstitial cells are referred to as Leydig cells.

Right Answe Is B
The endocrine tissue of the testes is made up of Leydig cells. These cells produce and secrete androgens, which are testicular hormones. Androgens are a class of male sex hormones that include testosterone.

Right Answe Is D
The 10-17th days of the menstrual cycle are the days of periodic abstinence. During this time period, couples do not have any sexual intercourse. This is due to the fact that ovulation is estimated on these days, and the chances of becoming pregnant are high.

Right Answe Is C
Sex is avoided in the ovulatory phase of the menstrual cycle for periodic abstinence which is estimated around days 10-17 of the menstrual cycle. The chances of becoming pregnant are high in the ovulatory phase.

Right Answe Is B
The practice of the male withdrawing the penis prior to ejaculation during intercourse is known as coitus interruptus. It has long been used as a natural method of birth control.

Right Answe Is B
Mendel gave the law of dominance and the law of segregation but he did not state incomplete dominance. The law of dominance states that when two contrasting alleles for a character coexist in an organism, only one is expressed and the other is not.
The character that is expressed is known as the dominant character, and the character that is not expressed is known as the recessive character. The law of segregation states that both parental alleles of the F1 generation split and are phenotypically expressed in the F2 generation. However, incomplete dominance refers to the expression of different phenotypes in progeny, other than the parental phenotypes.

Right Answe Is B
A red flowered Mirabilis Jalapa (RR) was crossed with the one with white flowers (rr). As a result, all F1 progeny were pink flowered (Rr). When F1 individuals were self-crossed, one plant with red flowers (RR), two plants with pink flowers (Rr), and one plant with white flowers (rr) was produced in the F2 generation. So the ratio of red, pink and white flowers was 1:2:1.

Right Answe Is C
Because neither allele is recessive and both alleles exhibit their phenotype in the heterozygous condition, as a result, progeny inherits the characteristics of both parents in co-dominance. For example, a cross between red and white Camellia flowers will produce flowers with both red and white colour.

Right Answe Is B
The character which is expressed in the F1 generation when two pure lines of opposite traits are crossed is called the dominant character.

Right Answe Is D
A histone octamer is a protein complex comprised of eight proteins of four types present at the core of a nucleosome. It is made up of two copies of each of the four histone proteins H2A, H2B, H3, and H4.

Right Answe Is B
Euchromatin is a type of chromatin (DNA) that is lightly packed, has a high number of genes, and can frequently participate in active transcription. However, heterochromatin is tightly packed (condensed form) DNA which can be darkly stained.

Right Answe Is D
Griffith’s experiment was the first to propose that bacteria can convey genetic information via a process known as transformation. Streptococcus pneumoniae was used in his experiments.

Right Answe Is D
When a bacterial population comes into contact with a specific antibiotic, those who are sensitive to it die. However, some bacteria that have undergone mutations become antibiotic-resistant.
As the competing bacteria die, such resistant bacterial strains survive and multiply rapidly. Resistance genes spread quickly, and the entire bacterial population becomes resistant. Thus, antibody-resistant bacteria are an example of pre-existing variation.

Right Answe Is A
The preserved remnants of plant and animal bodies are known as fossils. Sedimentary rocks are made up of material that has been broken up and worn away from older rocks. Plant and animal remains are buried beneath layers of sedimentary materials such as rock, sand, and clay, which hardens over time to create rock remnants.

Right Answe Is B
During directional selection (a type of natural selection), the population shifts in one direction. This means that directional selection supports small or large-sized individuals, and more of those individuals will be present in future generations.
The peppered moth’s evolution is an evolutionary example of directional colour change (from light to dark) in a moth population as a result of air pollution during the Industrial Revolution.

Right Answe Is C
Salmonella typhi, which affects the small intestine, causes typhoid. One of the most feared and common complications of typhoid fever is intestinal perforation. Vibrio cholerae is the microbe or bacteria that causes cholera.
This bacterium’s toxin causes the body to secrete massive amounts of water, resulting in diarrhoea and rapid fluid and salt loss. Both tuberculosis (TB) and diphtheria affect the respiratory system.

Right Answe Is A
Salmonella typhi causes typhoid. It is a gram-negative bacterium. These pathogens usually enter the small intestine through contaminated food and water and then transmit to other organs through the blood. The symptoms of typhoid include weakness, stomach pain, headache, diarrhoea or constipation, loss of appetite and intestinal perforation in the worst condition.

Right Answe Is A
The Widal Test is a clinical process used to diagnose typhoid fever. Diphtheria is confirmed by the Schick Test, cervical cancer is detected by the Pap Smear Test, and dengue fever is diagnosed by the Tourniquet Test

Right Answe Is C
Superovulation is the release of a large number of mature eggs in a single menstrual cycle by female cattle using drugs.
Embryo transplantation is a method of artificial breeding in which newly formed embryos are removed from a superovulated female animal and implanted into the uterus of other surrogate females. Superovulation and embryo transplantation are both used to increase the productivity of livestock breeds.

Right Answer Is D
Ranikhet disease is also known as New Castle or Doyle’s disease. It is an acute infectious, and highly contagious hen disease that causes respiratory distress, nervous symptoms, and high mortality in them. This disease is caused by a virus called Newcastle Disease Virus (NDV).

Right Answer Is C
Worker bees are sterile females and unable to reproduce. They perform all hive functions and are thus known as worker honey bees. They are in charge of honey maturation, larvae and drone feeding, grooming of the queen, cleaning of the cells, wax production, pollinating flowers, and much more.

Right Answer Is A
Saccharomyces cerevisiae, also known as Baker’s yeast, is used in the production of bread and a variety of other bakery products. It is used for the fermentation process performed by yeast on the starch present in flour.
The fermentation process helps in the conversion of starch into alcohol and carbon dioxide. The carbon dioxide gas in the dough causes the bread dough to rise and gives the bread softness and fluffiness after it is baked.

Right Answer Is C
Swiss cheese has very large holes. The large holes are produced by a bacterium called Propionibacterium shermanii by producing a large amount of carbon dioxide gas.

Right Answer Is D
Commercially important products such as beverages and antibiotics are produced on a large scale under controlled conditions through the fermentation process. As a result, a large vessel known as a fermentor is required for this process.

Right Answer Is B
A transgenic plant is one that contains one or more genes from another organism or plant. The first transgenic plant was created in 1983 which was antibiotic-resistant and it was a tobacco plant.

Right Answer Is A
RNAi (RNA Interference) is a self-defence mechanism of eukaryotic cells that specifically prevents virus infection. It can prevent the expression of critical viral proteins by directing viral mRNA to be degraded by cellular enzymes. In plants, RNAi is an effective antiviral agent.

Right Answer Is B
Golden rice is a transgenic basmati rice variety that produces a high yield and is high in vitamin A. It was created through the genetic modification of biosynthesised beta-carotene which is a precursor of vitamin A.

Right Answer Is B
Bacillus thuringiensis is a commonly occurring bacteria in soil that creates a protein toxin which kills insects. The Bt-toxin gene was excluded from Bacillus thuringiensis and inserted into several crop plants, including cotton, to create transgenic crops. Bt-cotton is one of the transgenic crops which is insect-resistant but not pesticide-resistant.

Right Answer Is A
The connecting peptide, also known as the C-peptide, is a short protein with 31 amino acids. It links the proinsulin molecule’s A and B chains. During the maturation process, the C-peptide chain is removed from the proinsulin molecule leaving behind A and B chains that are linked together by disulphide bonds to form an active insulin molecule.

Right Answer Is A
GEAC is an abbreviation for Genetic Engineering Approval Committee. The Indian government established this organisation to make decisions about the validity of genetically modified organism research and the safety of bringing GM organisms into public services.

Right Answer Is A
Number of paramoeciums at initial time = 50 Number of paramoeciums at the final time (after 1 hour) = 150 Population growth rate = 150 – 50 per hour = 100 per hour

Right Answer Is C
A population with more younger people than older people will increase in size because the number of people in the reproductive age group is large, and this group of individuals will enter reproductive age in the coming few years.

Right Answer Is D
The processes which influence the population density in a specified habitat are natality, mortality, immigration and emigration. Natality is the number of births in a population over a given time period. The number of deaths among a population over a given time period is referred to as mortality.
The number of people arriving from other habitats in a specific period of time is referred to as immigration. The number of people leaving a given population in a specific period of time is referred to as emigration. As a result, mortality and emigration reduce population density whereas natality and immigration increase it.

Right Answer Is D
Photosynthetic organisms capture approximately 1-5% of incident solar energy, or 2-10% of PAR (Photosynthetically Active Radiations), for organic matter synthesis i.e. Gross primary productivity (GPP). Approximately 20% of it is used in respiration, resulting in net energy capture (net primary productivity) of 0.8-4% of incident radiation or 1.6-8% of PAR.

Right Answer Is B
The parasitic food chain is a kind of food chain that begins with a herbivore but transfers food energy from larger life forms to smaller ones. Either the producer or the consumer is attacked by the parasite in this type of food chain.
The given food chain is parasitic because fruit-eating birds eat trees in this food chain. Lice feed on these birds as parasites. Microscopic organisms like bacteria can infect lice later on to complete the chain.

Right Answer Is D
The amount of organic matter (biomass) synthesised by plants during the photosynthesis process per unit area over time is referred to as primary productivity. It is determined by the plant species that inhabit a specific area. It is also affected by environmental factors such as temperature, solar radiation availability, nutrient availability, and the plant’s photosynthetic capacity.

Right Answer Is C
Natural resources are the raw materials or substances found naturally or which exist without the intervention of humans. Conservation of natural resources is extremely crucial for the preservation of biological diversity.

Right Answer Is D
On October 5, 1948, Julian Huxley established the International Union for Conservation of Nature (IUCN) in France. This organization acted on the conservation of the environment and sustainable resource use.

Right Answer Is D
Endangered species are those whose population has been reduced to a critical level and are at significant risk of extinction in the wild. Blackbuck, Brown spider monkeys, Indian Rhinos, Bengal tigers, Ganga river dolphins, and other endangered species are examples.

Right Answer Is B
A group of researchers working on Antarctica’s Atmosphere noted the Ozone Hole in 1980. This Ozone hole is thought to be the most depleted part of the Ozone Layer. The Ozone hole can be found over the South Pole.

Right Answer Is A
Smog is essentially a mixture of smoke, which contains multiple kinds of minute particles such as carbon and ash, and fog water droplets. Thus, it is a combination of smoke and fog.

Right Answer Is D
The physical world, in which an organism lives, is made up of nonliving components such as landforms, water sources, temperature, climate, humidity, and air. As a result, they are a component of the physical environment. The Biological Environment, on the other hand, includes all living organisms.