Biology Chapter on Immunology and Genetic Techniques

The total amount of organic matter produced by primary producers in a given area over a specific time period.

The amount of organic matter produced by primary producers that is available for consumption by heterotrophs after accounting for the respiration of the producers.

The rate of formation of new organic matter by consumers (heterotrophs) in an ecosystem.

The process by which plants or other photosynthetic organisms convert light energy into chemical energy.

The breakdown of organic matter by organisms such as bacteria and fungi, releasing energy and inorganic nutrients back into the environment.

The process by which organisms break down glucose to release energy in the form of ATP.

A series of actions or processes involving the transfer of energy and nutrients through an ecosystem.

A network of interconnected food chains in an ecosystem.

A population pyramid with a wide base indicates a large proportion of young individuals. This suggests a high birth rate and a growing population.

The competitive exclusion principle states that two species with similar ecological requirements (niche) cannot coexist in the same habitat for long. The species with a competitive advantage will outcompete the other.

Chemosynthetic bacteria are the primary producers in deep-sea hydrothermal vent ecosystems. They use energy from chemical reactions, rather than sunlight, to produce food.

A dihybrid test cross involves crossing an individual with a known genotype (heterozygous for two traits) with a homozygous recessive individual. This helps determine the genotype of the unknown individual.

Statins are cholesterol-lowering drugs that are produced by the fungus Monascus purpureus. These drugs help reduce the levels of cholesterol in the blood, preventing heart disease.

Activated sludge treatment is a method of wastewater treatment where a portion of the decomposer bacteria (sludge) is recycled to the beginning of the process. These bacteria help break down organic matter in the sewage.

A palindromic sequence is a DNA sequence that reads the same backward as forward. For the sequence 5' ATTGCAAT 3', the palindromic sequence is 3' TAACGTTA 5'.

The law of segregation states that during gamete formation, alleles for a trait separate from each other so that each gamete receives only one allele from each pair. This ensures that offspring inherit one allele from each parent.

Single nucleotide polymorphisms, or SNPs, are variations in a single nucleotide (base) at a specific position in the DNA sequence. They are common genetic variations that occur in human populations and are used in various fields, including genetic mapping, disease association studies, and personalized medicine.

Oogenesis is the process of female gamete (ovum) formation, starting with an oogonium, a diploid germ cell. It involves meiosis and differentiation stages.

Adaptive radiation is the rapid diversification of a lineage into a variety of forms with different adaptations to occupy a range of ecological niches. It occurs when a species colonizes a new environment with little competition and diverse resources, like Darwin’s finches on the Galapagos Islands, which adapted to feed on different types of seeds.

Gel electrophoresis is a powerful technique that separates molecules based on their size and charge. It uses an electric field applied to a gel matrix. Smaller molecules migrate faster through the gel, resulting in distinct bands based on size.

Lymphoid organs are tissues involved in the production, maturation, and/or storage of lymphocytes, which are white blood cells critical for the immune system. Lymph nodes filter lymph fluid and house immune cells, while bone marrow is the site of hematopoiesis, producing all blood cells, including lymphocytes.

Acquired immunity, also known as adaptive immunity, is specific, meaning it targets particular pathogens. It involves memory cells, allowing for a faster and stronger response upon re-exposure to the same pathogen. This explains why someone who has had chicken pox in childhood is less likely to get it again. This type of immunity is called lifelong(permanent) immunity.

The two main lymphocytes responsible for acquired immunity are B cells and T cells. B cells produce antibodies, which bind to and neutralize pathogens. T cells directly kill infected cells or activate other immune cells.

Transcription is the process of copying genetic information from DNA to RNA, mediated by RNA polymerase. In the given step, RNA polymerase is adding nucleotides to the growing RNA chain (B) using the DNA template (A). The enzyme is assisted by a transcription factor (C). Without C, RNA polymerase wouldn't bind to DNA and initiate the transcription process.

RNA polymerase III is responsible for transcribing tRNA, 5S rRNA, and snRNA (small nuclear RNA). These RNA molecules are essential components involved in protein synthesis and RNA processing.

Capping is the addition of a 7-methylguanosine cap to the 5' end of a pre-mRNA molecule, protecting it from degradation and enhancing its translation. Tailing is the addition of a poly-A tail to the 3' end of a pre-mRNA molecule, increasing stability and aiding in export from the nucleus.

hnRNA stands for heterogeneous nuclear RNA. It is the primary transcript of a gene, containing both introns and exons. It undergoes several processing steps, including splicing, capping, and tailing, to become mature mRNA.

Parasitism is a symbiotic relationship where one organism (parasite) benefits at the expense of another organism (host). For example, a tapeworm residing in the human intestine draws nutrients from the host, causing harm to the host.

Gause's competitive exclusion principle states that two species competing for the same limited resources cannot coexist stably in the same ecological niche. The species with a competitive advantage will eventually outcompete and eliminate the other.

The thymus is a primary lymphoid organ responsible for the maturation of T lymphocytes (T cells). It releases mature T cells, which are crucial for cell-mediated immunity and recognition of foreign antigens.

ADA deficiency, also known as Severe Combined Immunodeficiency (SCID), is a genetic disorder caused by a mutation in the ADA gene, leading to a deficiency in the enzyme adenosine deaminase. This deficiency affects the immune system, making individuals highly susceptible to infections.

Gene therapy for ADA deficiency involves introducing a functional copy of the ADA gene into the patient's cells using a viral vector. This allows the cells to produce the ADA enzyme, restoring the immune system's function. However, it is not a permanent cure as the introduced gene may not be integrated into all cells permanently.

A restriction enzyme that cuts both DNA strands at a specific recognition sequence, leaving single-stranded overhangs called sticky ends. It recognizes the sequence 5'-GGATCC-3' and cleaves between the G and G on each strand.

The objective is to create fragments of DNA with specific sequences that can be ligated into vectors or other DNA molecules for cloning or other genetic manipulations. These sticky ends allow for the efficient joining of DNA fragments.

The gene of interest is inserted into a vector by cutting both the gene and the vector with the same restriction enzyme. This creates compatible sticky ends that anneal together. Ligase enzyme then joins the DNA fragments to create a recombinant plasmid.

You would expect two DNA fragments. The BamHI site is present in the given DNA sequence, so the enzyme will cut the sequence into two fragments.

Fragment 1: 5'-ATTTTGAGGAT-3' 3'-TAAAACTCCTAG-5'

Fragment 2: 5'-CCGTAATGTCCT-3' 3'-GGCA TTACAGGA-5'

Introducing the gene M at the BamHI site disrupts the original antibiotic resistance gene in pBR322. This can be used to identify recombinant plasmids because they will lose their resistance to a specific antibiotic. Non-recombinant plasmids will retain the intact antibiotic resistance gene.

The palindromic nucleotide sequence is 3'-CTTAAG-5'.

The restriction endonuclease that recognizes this sequence is EcoRI.

Sticky ends are produced when a restriction enzyme cuts DNA unevenly, leaving single-stranded overhangs at each end. These overhangs are complementary to each other and can base pair, allowing for the joining of DNA fragments with compatible sticky ends.

Microbes, particularly bacteria, play a crucial role in controlling diseases caused by harmful bacteria through various mechanisms like competition, predation, and the production of antibacterial substances. These beneficial microbes outcompete harmful pathogens for resources, directly kill them, or inhibit their growth, effectively reducing the incidence of diseases. For instance, probiotics, which are live microorganisms that benefit the host, are used to restore balance in the gut microbiome and control harmful bacteria causing gastrointestinal disorders.

ADA deficiency is a genetic disorder where the enzyme adenosine deaminase is missing or defective. This enzyme is crucial for the immune system's proper functioning. Possible treatments for ADA deficiency include enzyme replacement therapy (ERT), gene therapy, and bone marrow transplantation. ERT involves providing the missing enzyme to patients. Gene therapy aims to introduce a functional ADA gene into the patient's cells. Bone marrow transplantation replaces the defective bone marrow with healthy bone marrow from a compatible donor.

Sporopollenin is a highly resistant polymer found in the walls of pollen grains and spores of plants. It provides protection to these structures from harsh environmental conditions like UV radiation, extreme temperatures, and chemicals. The chemical nature of sporopollenin makes it resistant to degradation, allowing pollen grains and spores to survive for long periods, enabling plant reproduction and dispersal.

The species-area relationship is represented by the formula S = CA^z, where S is the number of species, A is the area, C is a constant, and z is the slope of the line. This equation suggests that as the area increases, the number of species also increases, but at a decreasing rate. Over-exploitation of beneficial species can have detrimental effects on biodiversity, leading to a decrease in the number of species. A prime example is the overfishing of cod in the North Atlantic, which has led to a decline in the cod population and a disruption of the entire marine ecosystem, impacting other species that depend on cod as a food source.

Drug tests on athletes are conducted to ensure fair play and prevent athletes from gaining an unfair advantage by using performance-enhancing drugs. These tests are crucial to maintain the integrity of sports and protect the health of athletes. The authorities usually look for drugs that stimulate muscle growth, enhance performance, or mask other performance-enhancing drugs. These drugs can include anabolic steroids, erythropoietin (EPO), and stimulants like amphetamines. Anabolic steroids are derived from plants such as Dioscorea species and are used to enhance muscle growth and strength. EPO, a hormone that stimulates red blood cell production, is obtained from humans or through recombinant DNA technology. Stimulants, like amphetamines, are derived from Ephedra sinica and are used to increase alertness and reduce fatigue.

Prokaryotic cells lack a defined nucleus, but their DNA is not scattered randomly throughout the cell. The DNA is concentrated in a specific region called the nucleoid. The nucleoid is not membrane-bound, but it is organized and associated with proteins that help to compact and organize the DNA. This ensures that the DNA is properly replicated and transcribed, maintaining the cell's genetic information despite the absence of a true nucleus.

A test cross is performed when a geneticist needs to determine the genotype of an individual with a dominant phenotype. In this cross, the individual with the dominant phenotype is crossed with a homozygous recessive individual. The resulting offspring's phenotype reveals the genotype of the individual with the dominant phenotype. For example, if the individual with the dominant phenotype is heterozygous, the offspring will exhibit a 1:1 ratio of dominant to recessive phenotypes. If the individual is homozygous dominant, all offspring will exhibit the dominant phenotype. To carry out a test cross, the individual with the dominant phenotype is crossed with a homozygous recessive individual. The offspring's phenotypes are then observed and analyzed to determine the genotype of the individual with the dominant phenotype.

The hormone responsible for the growth of A, B, and C in the ovary is follicle-stimulating hormone (FSH). A represents the primary follicle, B represents the secondary follicle, and C represents the Graafian follicle. The hormone secreted by A is estrogen, and the hormone secreted by B is also estrogen, but in higher amounts compared to A. The hormone produced by D, which represents the corpus luteum, is progesterone. Progesterone is responsible for preparing the lining of the uterus for implantation of a fertilized egg. It also plays a role in regulating the menstrual cycle and maintaining pregnancy.