NEET 2024 Important PYQs and Graphs

A diagram used to predict the genotypes and phenotypes of offspring resulting from a cross between two parents.

A technique used to separate DNA fragments based on their size and charge, using an electric field applied to a gel matrix.

A type of organism that exhibits both radial and bilateral symmetry at different life stages. For example, starfish (Asterias) shows radial symmetry in adults and bilateral symmetry in larvae.

The phenomenon where a single gene influences multiple phenotypic traits.

The QRS complex on an electrocardiogram (ECG) represents the depolarization of the ventricles, which are the main pumping chambers of the heart.

A type of rib that does not connect to the sternum (breastbone), but instead ends freely in the abdominal muscles.

The initial stage in the life cycle of mosses, where the spores germinate and form a thread-like structure that develops into the mature moss plant.

Modified stems that grow above ground and help in vegetative propagation (producing new plants from non-sexual parts) in some plants like grasses and strawberries.

A hormone produced by the thyroid gland that regulates metabolism, growth, and development.

The presence of a true body cavity (coelom), which is a fluid-filled space between the body wall and the internal organs.

A technique used to amplify specific DNA sequences, making multiple copies of the target DNA.

The digestive system of a cockroach, starting from the mouth.

ATP is used at two steps in glycolysis, a metabolic pathway that breaks down glucose for energy: 1) glucose to glucose-6-phosphate 2) fructose-6-phosphate to fructose-1, 6-diphosphate. These steps are called phosphorylation reactions, requiring a phosphate group from ATP.

The process of inhalation or breathing in, where air enters the lungs.

A plant hormone that promotes fruit ripening and also stimulates the production of female flowers in some plants.

The central dogma of molecular biology describes the flow of genetic information from DNA to RNA to protein.

Flowers that have a bilaterally symmetrical structure, meaning they can be divided into two equal halves by a single plane.

The amount of energy or organic matter produced by an ecosystem over a given period minus the amount lost through respiration.

The primary constriction in a chromosome, which is an important site for the attachment of spindle fibers during cell division.

An alga that stores mannitol as its reserve food material.

A type of bacterium found in the nodules of alder trees that can fix atmospheric nitrogen, which is essential for plant growth.

RNA polymerase III is responsible for the production of tRNA, 5S rRNA, and snRNA in eukaryotes. These molecules play crucial roles in protein synthesis and regulation.

Living organisms that are used to control pests and diseases in an environmentally friendly way. Some examples include Bacillus thuringiensis, Trichoderma, and Baculovirus.

A process used to create plants with desirable traits, by culturing plant cells or tissues in a sterile environment. This technique enables the production of disease-free plants and allows for the creation of clones with identical genetic makeup.

Lactobacillus is a type of bacteria responsible for producing lactic acid, which is used in the process of making curd or yogurt.

A flower is formed when the shoot apical meristem changes into a floral meristem, leading to the development of specialized floral structures arranged on a condensed stem axis.

Radioactive probes are used to detect the presence of a specific sequence of DNA, including mutated genes. The probe hybridizes to the complementary sequence in the target DNA and can be visualized using autoradiography.

Lipids are organic molecules that are generally insoluble in water but soluble in organic solvents. They include fatty acids, glycerides, phospholipids, and steroids.

The process of transferring pollen grains from the male reproductive part (anther) of a flower to the female reproductive part (stigma) of the same or another flower to allow fertilization. This process is crucial for sexual reproduction in seed plants.

The rate of heartbeat, which is the number of times the heart beats per minute. It is determined by the cardiac output (amount of blood pumped per minute), stroke volume (amount of blood pumped per beat), and heart rate.

A genetic condition that affects males, characterized by the presence of an extra X chromosome (XXY). This leads to a variety of physical and developmental features, including taller stature, reduced fertility, and some feminine characteristics.

A phylum of animals that includes all vertebrates (animals with backbones) and are characterized by the presence of a notochord, a dorsal hollow nerve cord, a post-anal tail, and pharyngeal slits during some stage of their life cycle.

The phase of the cell cycle where the cell prepares for mitosis, including the duplication of chromosomes and centrosomes.

The presence of glucose and ketone bodies in the urine is a sign of diabetes mellitus.

A type of symbiotic interaction where both species benefit from the association. For example, in mycorrhizae, fungi and plant roots form a mutually beneficial relationship.

Genes that are physically located close together on the same chromosome tend to be inherited together, meaning they do not assort independently, which is a violation of Mendel's Law of Independent Assortment.

This pyramid is generally inverted in the marine ecosystem, meaning the lower trophic levels (producers) have less biomass than the higher trophic levels (consumers). This is because producers are microscopic phytoplankton, and they can reproduce very quickly. Even though they have a small individual biomass, they have a high collective biomass.

The first step in cellular respiration, where glucose is broken down into pyruvate, generating a small amount of ATP and reducing power (NADH) which is an electron carrying molecule.

The swollen receptacle, which is the base of the flower, has become the main fleshy part of the fruit in fruits like apples and pears. The actual ovary and seeds are often small and enclosed within the swollen receptacle, thus making them false fruits.

The colored part of the eye that controls the diameter of the pupil, allowing more or less light to enter the eye.

A fungus that produces the immunosuppressive molecule cyclosporin A, which is used to prevent rejection after organ transplantation.

Specialized lymphatic capillaries in the small intestine that absorb dietary fats and transport them to the bloodstream.

Heroin is a highly addictive drug derived from morphine, a naturally occurring opioid found in opium poppy. Heroin exerts its effect primarily on the cardiovascular system, leading to decreased heart rate and blood pressure.

A vector is a DNA molecule that is used to carry foreign DNA into a host cell for cloning purposes. Examples include bacterial artificial chromosomes (BACs), yeast artificial chromosomes (YACs), and plasmids like pBR322.

A toxic protein present in the seeds of castor beans, known for its potent toxicity. It disrupts protein synthesis and can be lethal if ingested.

The menstrual cycle is a series of cyclical changes in a female's reproductive system. During the cycle, the lining of the uterus (endometrium) thickens to prepare for pregnancy. If pregnancy does not occur, the lining is shed, resulting in menstruation.

A type of epithelium found in the proximal convoluted tubule of the nephron, specialized for reabsorption of substances from the filtrate. The brush border is formed by numerous microvilli, which increase the surface area for absorption.

Intrauterine devices (IUDs) that release hormones, such as progestin, to prevent pregnancy. They work by thickening cervical mucus, thinning the uterine lining, and inhibiting ovulation.

Amniocentesis is a prenatal diagnostic procedure used to obtain a sample of amniotic fluid, which contains fetal cells. It is primarily used to detect chromosomal abnormalities and genetic disorders, including sex determination. However, its use for sex determination is banned in many countries due to its association with female foeticide.

The spleen is a vital organ in the lymphatic system. It serves as a filter for blood, removing old and damaged red blood cells, platelets, and white blood cells.

Vultures are scavengers that feed on dead animals. They occupy the fourth trophic level in an ecosystem, which means they are consumers that feed on other consumers.

A horseshoe crab (Limulus polyphemus) is an ancient marine arthropod that has survived for millions of years. Its unique body shape and physiology, including its compound eyes and blue blood, have made it a valuable subject of scientific study.

The lac operon is a group of genes in bacteria that are involved in lactose metabolism. These genes are regulated by a repressor protein, which binds to the operator region of the operon and blocks transcription. When lactose is present, it binds to the repressor, causing it to detach from the operator, allowing transcription of the lac genes.

A surgical method of contraception in males, where the vas deferens - the tube that carries sperm from the testes - is cut and tied. This prevents sperm from being ejaculated, effectively preventing fertilization.

Osteoporosis is a condition characterized by a decrease in bone mass and density, making bones brittle and more prone to fractures. While there are several contributing factors, a common cause is a decrease in estrogen levels, particularly in postmenopausal women.

The amount of thymine in a DNA molecule is equal to the amount of adenine, while the amount of guanine is equal to the amount of cytosine. This is known as Chargaff's rule.

Restriction endonucleases are enzymes that cut DNA at specific sequences called palindromic sequences. These sequences read the same backward as forward. The enzyme cuts the DNA strand a little away from the center of the palindromic site, leaving 'sticky ends' that can be used for joining DNA fragments. They are crucial tools used in genetic engineering to manipulate DNA.

A protein is a chain of amino acids linked together by peptide bonds. The first amino acid in the chain is called the N-terminal, and the last amino acid is called the C-terminal. The sequence of amino acids determines the protein's structure and function.

Saprophytes are organisms that obtain their nourishment from dead organic matter. They play a crucial role in decomposition, breaking down complex organic molecules into simpler forms, which are then released back into the environment.

The vas deferens is a tube that transports sperm from the epididymis to the urethra. It receives a duct from the seminal vesicle (which contributes fluids to the semen) and joins the urethra at the ejaculatory duct.

Eosinophils are a type of white blood cell that is involved in allergic reactions and parasitic infections. They release histaminase, which breaks down histamine, and other enzymes that help to fight off parasites.

Metagenesis is a type of life cycle that involves alternating generations between a sexually reproducing stage and an asexually reproducing stage. While metagenesis is observed in some groups like cnidarians, it is not characteristic of helminths (worms).

Hemodialysis is a process used to filter the blood of people with kidney failure. During hemodialysis, the patient's blood is passed through an artificial kidney machine, which removes waste products and excess fluid. This procedure can lead to reduced absorption of calcium ions from the gastrointestinal tract and decreased production of red blood cells (RBC) due to the removal of erythropoietin (a hormone that stimulates RBC production) present in the blood.

Alfred Sturtevant established the concept of gene mapping, which relates the frequency of recombination between genes to their physical distance on a chromosome. This allowed scientists to create genetic maps of chromosomes, showing the relative positions of genes.

A cattle egret and a cattle in a field exhibit a symbiotic relationship called commensalism. The egret benefits by feeding on insects disturbed by the cattle, but the cattle are neither harmed nor helped by the egret's presence.

The gene named 'I' controls the ABO blood groups in humans. It has three alleles: IA, IB, and i. IA and IB produce different types of sugar molecules on red blood cells, while the allele 'i' does not produce any sugar. An individual inherits two alleles for this gene, one from each parent. When both IA and IB alleles are present, they express the same type of sugar, leading to the AB blood group.

Spermatogenesis is the process of sperm production in males, which occurs continuously from puberty onwards. In contrast, oogenesis, the production of eggs in females, begins before birth and is not continuous.

Erythropoietin, a hormone that stimulates the production of red blood cells (RBC), is produced primarily by the kidneys. The kidneys detect low oxygen levels in the blood and release erythropoietin, which travels to the bone marrow and stimulates the production of RBCs.

Ball-and-socket joints are a type of synovial joint that allows for a wide range of motion, including flexion, extension, abduction, adduction, rotation, and circumduction. An example is the joint between the humerus (upper arm bone) and the pectoral girdle (shoulder joint).

All vertebrates are chordates, meaning they belong to the phylum Chordata. However, not all chordates are vertebrates. Some chordates, like tunicates (sea squirts) and cephalochordates (lancelets), are invertebrates.

Insulin, a hormone that regulates blood sugar levels, is produced by the pancreas. Initially, it is synthesized as a prohormone, which contains an extra peptide called the C-peptide. This proinsulin needs to be processed to remove the C-peptide and form the active insulin, consisting of A and B chains linked together by disulfide bonds.

The Bt toxin produced by Bacillus thuringiensis is a protein that acts as an insecticide. Protoxin is an inactive form of the toxin, which needs to be activated in the alkaline pH of the bollworm's gut. The alkaline environment triggers the conversion of protoxin into the active toxin.

A competitive inhibitor is a type of inhibitor that binds to the active site of an enzyme, interfering with the binding of the substrate. The inhibitor resembles the substrate in its molecular structure and competes with it for the active site.

Typhoid fever is a serious bacterial infection caused by Salmonella typhi, transmitted through contaminated food and water. The Widal test is used to confirm the diagnosis, detecting antibodies against the bacteria in the patient's blood.

Skeletal muscle is responsible for voluntary movements. Its striated appearance is due to the arrangement of actin (thin filaments) and myosin (thick filaments), which create a pattern of dark and light bands.

Acquired immunity is the body's specific defense mechanism that develops after exposure to pathogens. It involves the production of antibodies and specialized immune cells that can recognize and fight off specific pathogens. Primary response occurs during the first encounter with a pathogen, while the anamnestic response is a faster and stronger response during subsequent encounters.

G0 phase is a non-dividing phase in the cell cycle, where cells are metabolically active but not actively dividing. Cells in G0 phase have exited the cell cycle and may remain in this phase indefinitely or re-enter the cell cycle at a later time.

The origin of replication (Ori site) is a specific DNA sequence where DNA replication is initiated. It serves as a starting point for the replication process, allowing the DNA to be copied and replicated.

The ribs are bones that make up the rib cage, providing protection for the heart and lungs. There are 12 pairs of ribs in the human body, classified into three types: vertebrosternal (true ribs), vertebrochondral (false ribs), and vertebral (floating ribs). Vertebrosternal ribs directly connect to the sternum, vertebrochondral ribs connect to the sternum through cartilage, while vertebral ribs do not connect to the sternum.

Histones are proteins that play a crucial role in packaging and organizing DNA within the nucleus of eukaryotic cells. They are positively charged, allowing them to bind to negatively charged DNA. Histones are rich in the amino acids lysine and arginine, which contribute to their positive charge. They are organized into units of eight molecules called histone octamers, around which DNA is wrapped to form nucleosomes.

Genetically engineered insulin was developed to overcome the limitations and potential allergic reactions associated with using insulin extracted from animals (cattle or pigs). Human insulin genes were introduced into bacteria (E.coli), which then produced human insulin. This method is safer and more effective than using animal-derived insulin, as it is identical to human insulin and less likely to cause allergies.

During anaphase of mitosis or meiosis, the centromeres split, and the sister chromatids separate, moving to opposite poles of the cell. This segregation of chromosomes ensures that each daughter cell receives a complete set of chromosomes.

Allen's Rule states that animals living in colder climates tend to have shorter extremities (limbs, ears, and tails) compared to animals living in warmer climates. This adaptation helps to reduce heat loss by minimizing the surface area exposed to the cold.

When the ventricular pressure exceeds the pressure in the aorta and pulmonary artery, the semilunar valves open, allowing blood to flow from the ventricles into the arteries. Conversely, when ventricular pressure falls below the pressure in the arteries, the semilunar valves close, preventing backflow of blood into the ventricles.

The atrioventricular node (AVN) is a specialized group of cells located in the heart that delays the conduction of electrical impulses from the atria to the ventricles. This delay allows the atria to contract and fill the ventricles with blood before the ventricles contract.

Bronchioles are small airways in the lungs that branch off from the bronchi. They are lined with ciliated epithelium, which helps to move mucus and debris out of the lungs.

Tendon is a strong, fibrous connective tissue that attaches muscle to bone. It is composed mainly of dense regular connective tissue, which is arranged in parallel bundles of collagen fibers providing strength and flexibility.

Adipose tissue is a type of loose connective tissue that stores fat cells. It is a major energy reserve and also insulates the body against heat loss.

The scapula, also known as the shoulder blade, is a triangular bone located on the back of the rib cage. It forms part of the shoulder joint and provides attachment points for several muscles.

Basophils are a type of white blood cell that secretes histamine, serotonin, and heparin. Histamine is involved in allergic reactions and inflammation, while serotonin is a neurotransmitter and heparin is an anticoagulant.

The release of antidiuretic hormone (ADH) from the posterior pituitary gland is triggered by increased blood osmotic pressure. ADH facilitates water reabsorption in the kidneys, reducing the amount of water lost in urine. The renin-angiotensin-aldosterone system (RAAS) also plays a role in regulating blood pressure. Angiotensin II, produced by the RAAS, causes vasoconstriction, increasing blood pressure.