General Biology 2 LMs Past Paper AY 24-25 PDF

General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Guide: Unit: Objectives of Animal Breeding: Subtopics: I. Increase Yield of Animal Products (wool, milk,...

General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Guide: Unit: Objectives of Animal Breeding: Subtopics: I. Increase Yield of Animal Products (wool, milk, eggs) Contents: II. Improve Docility (less aggression) Unit 1.0 Applied Genetics III. Cultivate Good Mothering Ability 1.1 Introduction to Breeding IV. Resistance Against Diseases 1.2A Timeline: Plant Breeding V. Improve Meat Quality and Quantity 1.2B Timeline: Animal Breeding 1.3A Classical Breeding: Overview What is Captive Breeding? 1.3B Classical Breeding: Plants 1.3C: Classical Breeding: Animals Captive Breeding - controlled reproduction of 1.4 Modern Breeding Techniques animals in a managed environment, such as 1.5 Unit Fundamental Concepts sanctuaries or breeding facilities, to preserve endangered species and increase population numbers. 1.0 Applied Genetics Captive breeding is characterized by the ff: Applied genetics is the practical application of genetic principles to improve organisms in fields 1.​ Controlled/predetermined environment, like medicine, agriculture, and biotechnology. 2.​ The objective is to repopulate endangered species (prevent species extinction), 1.1 Introduction to Breeding 3.​ No selection of desired traits (main goal is to repopulate), and Breeding - controlled process of subjecting 2 4.​ It improves biodiversity. parent organisms in sexual reproduction to produce offspring with desired traits. Examples of animals bred in captivity: Two classifications of Breeding: 1.​ Philippine Crocodile (Crocodylus mindorensis), and 1.​ Classical Breeding - traditional process of 2.​ Philippine Eagle (Pithecophaga jefferyi) selecting a desired trait or characteristic to improve in animals and plants. Both are critically endangered species Alternative Terms: Conventional Breeding, endemic to the Philippines. Traditional Breeding, Selective Breeding 1.2A Timeline: Plant Breeding 2.​ Modern Breeding - the process of breeding organisms with the inclusion of the ff key Overview: terms: 9000 B.C. - Tigris River a.​ Human Intervention, 1694 - Rudolph Camerarius b.​ Technological 1719 - Thomas Fairchild Advancements/Engineering, and 1766 - Joseph Koelreuter c.​ Genetic Modification. 1866 - Gregor Mendel 1926 - Pioneer Company Why Do Humans Breed Plants and Animals? 1960s - Norman Borlaug Objectives of Plant Breeding: Tigris River (9000 B.C.) I. Resistance (to what?): a.​ Stress/Environmental Conditions (Drought, Tigris River - flows through Turkey, Syria, and Iraq Frost, Salinity, etc.) (Middle East), originating in Turkey's Taurus b.​ Resistance to Diseases (Bacterial, Fungal, Mountains and emptying into the Persian Gulf. It Viral) forms part of the Mesopotamian region (cradle of c.​ Resistance to Pests/Insects civilization) alongside the Euphrates River. II. Improve Nutrient Quantity III. Improve Processing Quality Relevance in Plant Breeding: IV. Increase Yield of Vegetative Parts and Grains 1.​ The first evidence of crop domestication was found on the Tigris River. Note: All insects that are detrimental to agriculture Barley, Chickpeas, Lentils, Peas, Wheat are pests, but not all pests are insects.  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Rudolph Camerarius (1694) Relevance in Plant Breeding: 1.​ His achievement proved that new plant ​ Camerarius was a German botanist and varieties could be intentionally created by physician. combining traits of different plant species. ​ Published his discovery about plant 2.​ Although lesser well-known than others on reproductive organs in his book “De Sexu this timeframe, his technique was a crucial Plantarum Epistola” in 1694. step in the development of modern plant (The book’s title roughly translates to: An breeding techniques. Epistle on the Sex of Plants) Joseph Koelreuter (1766) Relevance in Plant Breeding: 1.​ His experiments with maize plants showed ​ A German botanist who produced the first that plants, like animals, have distinct tobacco hybrid. sexes, from this, he proposed that new plant types can be produced from Relevance in Plant Breeding: crossing (cross-pollinating). 1.​ Interspecific Hybridization 1.1 Focus on Nicotiana Species - his focus Note: He only theorized the possibility, but of work are the different species within he did not actually prove his theory. the genus Nicotiana. These species exhibit variations in flower shape, size, and Additional Information: other characteristics. Parts of a Flower 1.2 Cross-Pollination - occurs through manually transferring pollen from anthers (M) of one species into the stigma (F) of another species. 1.3 Observation of Hybrid Offspring - he meticulously observed the hybrid offspring, noting their characteristics (flower color, size, shape, and leaf morphology) and how they differed from the parent plants. Figure 1. Parts of a Flower. 2.​ Reciprocal Crosses 2.1 Testing Parental Influence - he reversed Stamen (M) - Anther, Filament parental roles in hybridization. e.g. if he Pistil (F) - Stigma, Style, Ovary initially crossed species A (pollen) with species B (stigma), he would then cross Male Gamete: species B (pollen) with species A (stigma). ​ Pollen: Plants; Sperm: Animals “Pollen is to Plants as Sperm is to Animals.”​ Note: Pollen is a gamete, whereas the ​ stigma is a reproductive structure Female Gamete: functioning as the receptor for pollen. Egg Cell. ​ 2.2 Investigating Inheritance Patterns - Thomas Fairchild (1719) through reciprocal crosses, he was able to investigate if the inheritance of traits was ​ Was a British gardener. influenced by the sex of the parent plant. ​ Pioneer of Hybridization. ​ Leading Nursery man of his day. Gregor Mendel (1866) ​ Conducted the first reported hybridization through cross-pollination between two ​ Was an Austrian Scientist and Monk (at the different, but closely-related species time of his garden peas experiments). (carnation x sweet william; both from the ​ He is known as the father of genetics. genus Dianthus) successfully resulting in a ​ Laid foundation to heredity of traits through new cultivar of carnation (Fairchild’s mule). his garden pea hybridization. Note: According to Britannica (2024): ​ His experiments and observations led to his Variety - naturally occurring. discovery of Mendel’s Laws of Cultivar - intentionally bred by humans for Inheritance. specific traits.  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Relevance in Plant Breeding: 1.​ Mendel’s Experimental Approach Note: While the Mendelian Laws of Inheritance are 1.1 Careful Selection of Traits - he ~100% accurate for simple traits, more complex meticulously chose pea (Pisum sativum) for traits generally follow non-Mendelian Laws of his experiments due to their distinct, easily Heredity. observable traits. These included: a.​ Flower Color - Purple/White Pioneer Hi-Bred International Inc. (1926) b.​ Seed Shape - Round/Wrinkled c.​ Seed Color - Green/Yellow ​ An American agricultural company founded d.​ Pod Shape - Constricted/Inflated in 1926. e.​ Pod Color - Green/Yellow ​ Global leader in the development and sales f.​ Flower Position - Axial/Terminal of genetically modified seeds, agricultural g.​ Plant Height - Dwarf/Tall chemicals, and crop protection products. 1.2 Controlled Crosses - he performed Relevance in Plant Breeding: controlled crosses between plants with 1.​ Significant contributions to the field of plant different traits by carefully transferring breeding, particularly in the development of pollen from the anther (M) of one plant to hybrid corn—in the 1930s, Pioneer the stigma (F) of another. He prevented scientists developed a technique for self-pollination to ensure accurate results. creating more productive and disease-resistant hybrid corn. This 1.3 Statistical Analysis - he recorded the breakthrough helped revolutionize characteristics of the offspring from each agriculture in the US and globally. cross over multiple generations. He then 2.​ Development of genetically modified (GM) analyzed the data using statistical crops. In the 1990s, Pioneer introduced a methods, allowing him to identify number of GM crops (corn, soybean, and consistent patterns of inheritance. cotton). These crops are engineered to be resistant to herbicides and insects; Additional Information: therefore, increasing yield and decreasing Mendelian (Mendel’s) Laws of Inheritance production costs. 1.​ Law of Dominance: Norman Borlaug (1960s) ​ In a pair of alleles (dominant and recessive), one allele may be ​ He lived from 1914 to 2009, he was an dominant over the other. American agronomist , humanitarian, and ​ The dominant allele determines the Nobel Peace Prize Laureate. organism's phenotype (observable ​ Father of Green Revolution—for pioneering traits), while the recessive allele is work in developing high-yielding wheat masked in the presence of the varieties. dominant allele. ​ During the Green Revolution, he introduced cultivation practices that boosted global 2.​ Law of Independent Assortment: production. ​ Alleles of different genes assort independently of one another during Relevance in Plant Breeding: gamete formation, provided the 1.​ Development of High-Yielding Wheat genes are unlinked (located on Varieties - Borlaug led the development of different chromosomes or far apart semi-dwarf, high-yielding varieties of on the same chromosome). wheat in the mid-20th century. These new ​ This means that the inheritance of wheat varieties were more resistant to one trait generally does not affect diseases and pests, and they produced the inheritance of another. significantly higher yields than traditional varieties. 3.​ Law of Segregation: 2.​ Introduction of Modern Agricultural ​ Each organism has two alleles for Practices - he not only developed new each trait (one from each parent). wheat cultivars, but also introduced ​ These alleles separate during modern agricultural practices such as gamete formation, so each gamete the use of fertilizers, pesticides, and carries only one allele for each trait. irrigation to farmers in developing ​ Offspring inherit one allele from each countries. parent during fertilization.  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 3.​ Impact on Global Food Production - his 2.​ Impact on Animal Breeding - his work on work led to significant increase in wheat genetics provided a crucial foundation for production in many developing countries, understanding the genetics basis of traits in helping to prevent widespread famine and animals. This knowledge is essential for improve food security for millions of people. developing effective breeding programs. 1.2B Timeline: Animal Breeding Ronald Fisher (1918) ​ He lived from 1890 to 1962, he was a Overview: brilliant statistician who made significant 1760s - Robert Bakewell contributions to both genetics and statistics. 1910 - Thomas Hunt Morgan ​ Father of Statistics - applied statistics in 1918 - Ronald Fisher breeding mice and livestocks. 1937 - Jay Lush 1940s - Lanoy Nelson Hazel Relevance in Animal Breeding: 1.​ Development of Statistical Methods - he Robert Bakewell (1760s) developed many of the statistical methods used in quantitative genetics including ​ Father of Modern Animal Breeding - he is methods for estimating genetic parameters credited for laying the foundation for modern and predicting breeding values. animal breeding practices. 2.​ Influence on Animal Breeding - his statistical methods have had a profound impact on Relevance in Animal Breeding: animal breeding. They are used to evaluate 1.​ Focus on Selective Breeding - he pioneered breeding programs, predict the genetic merit the concept of selective breeding by of animals, and make informed decisions carefully choosing the best animals for about which animals to select for breeding. breeding based on desired traits (size, weight, and meat quality). Additional Information: 2.​ Emphasis on Performance Records - 1.​ In a book titled “The Genetical Theory of Bakewell introduced the crucial practice of Natural Selection (1930),” he showed the keeping detailed records of an animal’s Integration of Mendelian Laws with performance. Such records allowed for the Darwin’s Theory of Natural tracking of traits like weight gain, milk Selection—explaining why variations on production, and wool yield, which were then traits continue to arise from combined used to select the most desirable breeding effects of many discrete genes. stock. 2.​ Development of the Analysis of Variance 3.​ Impact on Livestock Breeding - his method’s (ANOVA) statistical method to partition the revolutionized the breeding of livestock, total phenotypic variation in a population particularly sheep, cattle, and horses. He into components: genetic variance and developed several new breeds, including environmental variance. the Dishley Merino sheep and the 3.​ Development of Regression and Longhorn cattle. Correlation methods - study the relationship between parental and offspring Thomas Hunt Morgan (1910) traits. 4.​ Statistical Hypothesis Testing and ​ He lived from 1866 to 1945, he was a Maximum Likelihood Estimation - used geneticist and a Nobel Physiology Prize for analyzing genetic data; still used today Laureate - renowned for his significant for assessing significant differences in trait contributions to our understanding of means, impact of genetic factors, and fit genetics. models to genetic data. ​ He earned his Nobel Prize for his work related to breeding fruit flies (Drosophila Jay Lush (1937) melanogaster) for genetic studies. ​ He lived from 1896 to 1982, he was an Relevance in Animal Breeding: animal breeding pioneer and a prominent 1.​ Chromosomal (Chromosome) Theory of figure in the development of modern Inheritance - he and his team demonstrated breeding programs. that genes (the basic unit of inheritance) are ​ Proposed the use of genetic data in located on chromosomes. This discovery breeding rather than subjective visual provided the physical basis for understanding how traits are inherited.  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 evaluation of animals (based on appearance). Progeny - refers to the offspring of organisms that have undergone breeding, often carrying the Relevance in Animal Breeding: desired traits from both parents. It is used to 1.​ Focus on Quantitative Genetics - he collectively refer to the next generation. focused on applying quantitative genetics principles to improve livestock population. 1.3B Classical Breeding: Plant 2.​ Development of Breeding Programs - he developed and refined many of the breeding Classical Plant Breeding is divided into two programs used today, including selection categories: Cross Breeding and Selective Breeding. and mating systems designed to improve economically important traits. To easily remember the procedures performed in 3.​ Education and Training - he was a each of the classical plant breeding methods, you renowned educator and trained many of the must first carefully understand the objectives of leading animal breeders of his time. each. Lanoy Nelson Hazel (1940s) Cross Breeding VS Selective Breeding ​ He lived from 1911 to 1992, he was an Cross Breeding - Mating two different plant animal breeding theorist who made varieties or species to produce a hybrid with the significant contributions to the field. best traits of both. ​ He proposed the Selection Index Theory Alternative Term: Hybridization where multiple traits of an animal must be considered for selection. Example: Crossing IR8 (high-yielding rice variety) with Relevance in Animal Breeding: traditional rice varieties to create hybrids like 1.​ Focus on Quantitative Genetics - he IR64, which are high-yielding and pest-resistant. focused on the application of quantitative genetics principles to animal breeding. This Selective Breeding - selecting plants with involved using statistical methods to desirable traits within the same species and understand how traits are inherited and breeding them over multiple generations. passed onto offspring. 2.​ Development of Breeding Programs - he Example: played a key role in developing breeding Breeding sweeter sugarcane plants within the programs for livestock the importance of same species to enhance sugar content in future selecting animals based on their genetic generations. merit, which is an estimate of an animal’s breeding value. Comparison: ​ Cross Breeding introduces new traits 1.3A Classical Breeding: Overview from different varieties or species. ​ Selective Breeding improves traits within Classical Breeding - traditional process of the same variety or species over time. selecting a desired trait or characteristic to improve in animals and plants. Selective Breeding Methods: Alternative Terms: Conventional Breeding, Traditional Breeding, Selective Breeding 1. Mass Selection Method Heterosis (Hybrid Vigor) - the improved or Aims to improve the qualities of a crop by selecting increased function of an organism resulting from good-quality offspring every generation and the crossbreeding of two genetically different allowing them to open pollinate (both individuals. self-pollination and cross-pollination are allowed). In mass selection there is a wide range of Inbreeding - subjecting two closely-related crops of same variety but 2 or more desired organisms to concentrate specific traits. It is a traits are selected to produce a superior double-edged sword (figuratively). offspring every generation Outbreeding - the breeding of unrelated or Procedure: distantly related organisms to increase genetic Step 1: Select an initial population. diversity and avoid inbreeding depression. Step 2: Select desirable traits. Basically, it is the inverse of inbreeding.  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Step 3: Mixing seeds with desired traits to cultivate the next generation. Step 4: Field trials are done to test whether they are fit to the environment. Step 5: Releasing the new variety of crops. Example: Breeding of alfalfa. Figure 3. Illustration of Wheat Breeding Using Pure-Line Selection Method. Advantages: Disadvantages: 3. Clonal Selection Method Is applicable for good-quality hybrids that usually cannot reproduce (e.g., seedless); thus, only the vegetative or asexual reproduction of the plant is harnessed. Figure 2. Illustration of Alfalfa Breeding Using Mass Procedure: Selection Method. Step 1: Select an initial population of crops. Step 2: Acquire vegetative structures or 2. Pure-Line Selection Method organs. Step 3: Propagate the vegetative structures Aims to establish a breed that is homozygous for asexually. particular traits; thus, self-pollination is most Step 4: Determine which of the clones will applicable.It aims to maintain a consistent, uniform have superior traits. desired traits. Step 5: Perform further vegetative propagation of superior clones. Procedure: Step 1: Select an initial population of Example: Breeding of (navel) oranges and apples open-pollinating crops. are further improved through clonal selection. Step 2: Select desirable traits. Step 3: Allow pollination in these selected Advantages: Genetic Uniformity, Mass Production crops. of Specimens with Desired Traits, Preservation of Step 4: Grow progeny separately and Parent’s Genetic Traits, Takes Less Time, and perform selection among them. Decreases Chances of Cultivational Contamination. Step 5: Perform field trials for the selected crops. Disadvantages: Lack of Genetic Diversity, Not Applicable to All Plants, Subtle Decrease in Genetic Example: Breeding of wheat. Vigor Over Time, Negative Traits Are Copy-Pasted As Well, and Ethical Considerations. Cross Breeding/Hybridization Method Aims to combine two superior traits from different breeds or species of plants. Sometimes, it also results in eliminating the inferior traits present in the parent plants. This process involves the emasculation of one of the parent plants. Step 1: Identify two different crops with superior traits. Step 2: Identify two different crops with superior traits. Step 3: Emasculate the designated female parent plant.  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 (Emasculate - removal of the stamen to 3.​ Genetic Research – Helps study hereditary prevent self-pollination) diseases and traits in controlled conditions. Step 4: Obtain pollen from the other plant and introduce it to the female. Inbreeding Depression (Disadvantages): Step 5: Cover the female plant with 1.​ Increased Chances of Developing Genetic polyethylene plastic. Disorders 2.​ Lack of Genetic Diversity (Variation) Example: Improved crossbred plants include corn, 3.​ Gradual Decline of Superior Traits - due to sunflower, and cauliflower. increased homozygosity leading to inferior or harmful traits becoming more prevalent and fixated. Cross Breeding ​ Individuals from two different breeds are bred together. ​ Two individuals must be reproductively compatible. ​ Desirable traits from different breeds of animals are combined (accumulated). Example: The cross between two different breeds of horses, the American Saddlebred horse (A) and Arabian horse (B), produces the top-quality National Show horse breed for equestrian purposes. Figure 4. Illustration of Crossbreeding. Advantages: Hybrid Vigor, Increased Resistance Against Stressors, Increased Adaptability, 1.3C Classical Breeding: Animal Figure 5. Cross Breeding of Two Horse Breeds. Classical Animal Breeding is divided into two categories: Inbreeding and Crossbreeding. Advantage: Increased Genetic Variability. ​ Inbreeding Disadvantage: Increased Breeding Incompatibility. Subjecting two closely-related animals into 1.4 Modern Breeding Techniques breeding for accumulation or identification of specific traits. It involves the ff. key terms: First Generation: Superior Male + Superior a.​ Human Intervention, Female = Superior Progeny b.​ Technological Advancements/Engineering, ​ and Second Generation: Superior Parent + c.​ Genetic Modification. Superior Progeny = Sustained or Improved Superior Traits in Progeny. Somatic Hybridization Example: A superior female cattle that produces This technique involves fusing two somatic cells high amounts of milk can be mated to her sons (non-reproductive cells) from different plants to during inbreeding. create a hybrid. The cell walls are removed using enzymes, and the protoplasts (cells without cell Purpose: walls) are fused using an electric current or 1.​ Fixation of Desired Traits - ensures offspring chemical treatment. The resulting hybrid cell can inherit specific characteristics consistently. develop into a new plant with traits from both 2.​ Improvement of Genetic Purity/Developing parents. Purebred Lines - used in livestock and pet breeding to maintain breed standards. In essence, “Protoplasts from two different plants with desirable traits are fused to create a hybrid.”  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Disadvantages: Most mutations are deleterious, Example: The creation of new potato varieties with and it can be time-consuming to screen for improved disease resistance. beneficial ones (unpredictable outcomes). Artificial Reproductive Technologies This encompasses a range of techniques that manipulate the reproductive process of plants and animals. Specific Examples of the Technologies: 1.​ Artificial Insemination - manually transferring pollen from one plant to another. 2.​ In Vitro Fertilization - fertilizing eggs in a laboratory setting. 3.​ Embryonic (Embryo) Rescue - culturing immature embryos to ensure their survival Example: Figure 6. Somatic Hybridization Process. 1.​ Production of hybrid seeds in maize. 2.​ Some female cattle are artificially Moiety/Cell - somatic cell. inseminated by using semen collected from superior bulls. Protoplast - an isolated plant cell stripped off of its cell wall (for gene modification). Advantages: allows for controlled breeding, can overcome barriers to fertilization, genetic variability, Advantages: Can overcome sexual and diversity is sustained. incompatibility barriers between plants, allowing for the combination of desirable traits from different Disadvantages: labor-intensive may require species or varieties. specialized equipment, may yield unexpected outcomes, and are expensive. Disadvantages: It can be technically challenging and may result in unpredictable outcomes due to Genetic Engineering genetic instability. This involves the direct manipulation of an Mutation Breeding organism's genes using recombinant DNA technology. Genes from other organisms can be This method involves inducing mutations in the inserted into the plant's genome to introduce new plant's DNA using radiation (X-rays or gamma rays) traits. or chemical mutagens. These mutations can lead to new and desirable traits. Genetic engineering transcends classical breeding techniques and allows introduction of genes from a Mutagenesis - the actual process of inducing totally different organism. changes within an organism’s genetic material through exposure to mutagens. Example: Development of insect-resistant cotton and herbicide-tolerant soybeans. Example: 1.​ Development of semi-dwarf wheat varieties Advantages: Allows for precise and targeted with increased yield. modification of traits. 2.​ Soybeans are induced to mutate. Disadvantages: Raises concerns about potential Advantages: Can generate novel genetic variation environmental and health risks, and can be subject that may not be readily available in natural to regulatory (ethical) restrictions. populations (commercialization of rarely-occurring characteristics in crops).  General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 ​ The practice of breeding plants and animals not only aims to produce a sufficient number of offspring for several generations but to also improve the traits of the organism being bred. 1.5 Unit Fundamental Concepts ​ Plant breeding, being a major aspect of agriculture, aims to produce the quality and quantity of crops to address certain issues Breeding such as global food security concerns. ​ Plant breeding methods involve mass selection, pure-line selection, clonal selection, and crossbreeding. These methods differ in terms of their objectives, whether pollination is applied, the type of pollination, and the parent plants involved. Animal Breeding ​ Animal breeding, likewise, aims to improve livestock so that they produce better quality and quantity of animal products such as meat, eggs, wool, and dairy. ​ Breeding methods are applied for the conservation of animals with threatened status. ​ Animal breeding may involve inbreeding or crossbreeding. These two methods differ in terms of whether a new combination of superior traits is produced in the offspring. ~Nihil Sequitur~ Figure 7. Summary of Breeding Methods. ​ The earliest forms of plant and animal breeding involve the practice of domestication where wild organisms are bred to produce traits that will benefit humans. ​ Classical and modern breeding techniques are all founded on the fact that the DNA molecule stores and controls the expression of the genetic information. ​ Modern breeding methods are also practiced in both plants and animals. This may involve the fusion of cells (somatic hybridization), induced mutagenesis (mutation breeding), artificial reproductive technologies, and genetic engineering. Plant Breeding General Biology 2 LMs | SEM 2 Q3 | A.Y ‘24-’25 Prepared By: 12 - Hertz