Genetics Is a field of biology that studies how traits are passed from parents to their offspring. Study of heredity and variation Genetics is built around molecules called DNA Gene 1,Gene 2 Heredity is passing of traits from parents to offspring during reproduction (DNA is replicated) what makes children look like their parents Johann Gregor Mendel (1822-1884) "father of genetics" studied the inheritance of seven different features in peas (Pisum sativum), including height, flower color, seed color, and seed shape. cross pollinate (T x S = T = Self Fertilize = 3T + 1S) discovered fundamental law of inheritance because of his work in pea plants Mendel's Experiment First Filial Generation (F1) Tall x Short = Tall plant Second Filial Generation (F2) Tall x Tall = Tall & short plant Punnett Square Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach in 1905.

THREE LAWS OF INHERITANCE

1. LAW OF DOMINANCE if an organism inherits different alleles for the same trait, one allele may be dominant over the other. Trait a specific characteristic of an organism ex. Seed Color Gene Segment in DNA that controls a specific trait Alleles is a variant form of a gene (phenotype and genotype) Dominant a relationship between alleles of a gene, in which one allele masks the expression (phenotype) of another allele at the same locus. Express in Capital letters. Recessive able to be covered up by a dominant trait, expressed in small letters. Phenotype an individual's observable traits Genotype is an individual's collection of genes. The term also can refer to the two alleles inherited for a particular gene. Homozygous Dominant having two dominant alleles of a particular gene or genes (AA) Homozygous Recessive having two recessive alleles of a particular gene or genes (aa) Heterozygous Dominant having two different alleles of a particular gene or genes (Aa)

2. LAW OF SEGREGATION

• states that for each gene, an organism receives one allele from each parent. The alleles separate from each other in the process called segregation during which reproductive cells are formed.

3. LAW OF INDEPENDENT ASSORTMENT - the alleles of two (or more) different genes get sorted into gametes independently of one another. In other words, the allele a gamete receives for one gene does not influence the allele received for another gene. Genes for one trait are not inherited together with other traits. hindi pwedeng ma inherit ang parehas na trait. Monohybrid Cross is a genetic mix between two individuals who have homozygous genotypes, or genotypes that have completely dominant or completely recessive alleles, which result in opposite phenotypes for a certain genetic trait. responsible for the inheritance of one gene. 1 trait Dihybrid Cross is a cross between two different lines/genes that differ in two observed traits. We compare two different characteristics in a dihybrid cross. 2 traits

LESSON 2: NON-MENDELIAN PATTERNS OF HEREDITY

Non-Mendelian inheritance is any pattern of inheritance in which traits do not segregate in accordance with Mendel's laws. These laws describe the inheritance of traits linked to single genes on chromosomes in the nucleus. Incomplete dominance Crossing two parents with contrasting traits may result in an offspring of intermediate phenotype. one allele is not completely dominant over the other allele. Codominance Non- Mendelian pattern of inheritance in which the hybrids show the phenotypic characteristics of both alleles. Ex. Blood Type Multiple Alleles A non- Mendelian inheritance pattern that involves more than just typical two alleles that code for a certain characteristic. Ex. I^A Dominant I^B Dominant i Recessive

INCOMPLETE DOMINANCE. CODOMINANCE

Polygenic traits Polygenic traits are traits controlled by more than one gene and thus, their inheritance can be complicated. These traits show a very wide range of phenotypes. Ex. skin color, height , fingerprints Epistasis results when an allele of one gene hides or masks the visible expression of phenotype of another gene. It is entirely different from dominant and recessive genes. Sex-limited traits traits that are expressed in only one sex but not in the other due to the activation of sex hormones. Ex. Milk production in females and Growth of beard in males Sex-influenced traits traits that are expressed differently in the two sexes due to the influence of sex hormones. This makes the expression of traits more dominant in one sex and recessive in the other. Ex. Baldness

LESSON 3: SEX-LINKAGE AND PEDIGREE ANALYSIS

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA) DNA contains the specific instructions that make each type of living creature unique.

Types of Chromosomes Autosomal Chromosomes / Autosomes The non-sex chromosomes present in organisms are the autosomes. In humans, there are 22 sets of autosomes; they are labeled or referred numerically from 1 to 22, like chromosome 1, chromosomes 2, chromosomes 3, etc. are responsible for transferring the genetic information from parents to their offspring Sex Chromosomes / Allosomes chromosomes that play vital roles in determining the gender or sex of humans or other species of animals are known as sex chromosomes. These are named ‘X’ and ‘Y’ by scientists. In humans out of the 23 pairs of chromosomes, one pair is sex chromosomes, and the other 22 pairs are the autosomes. Sex Linkage describes the sex-specific patterns of inheritance and presentation when an allele is present on a sex chromosome (allosome) rather than a non-sex chromosomes (autosome) most cases of the heritable diseases sex specific patterns of inheritance X linked Traits - gene is located on the X chromosomes Y linked Traits - gene is located on the Y chromosomes

Pedigree Represent family members and relationships using standardized symbols. commonly used in analyzing the pattern of inheritance of a particular trait throughout the family or hereditary diseases.

Mode of Disease Autosomal Dominant Disorder tends to appear in every generation of the pedigree. Don't skip generation. Affected fathers and mothers transmit the disease to both sons and daughters. Affected parents can have unaffected child. Autosomal Recessive It skips generation Unaffected parents can have an affected child. X-linked Dominant All daughters of affected father are affected Mother tends to pass the disease to their son. X-linked Recessive All sons of affected mother are affected Unaffected father will never have an affected daughter Y-linked Disease Y-linked traits never occur in females, and occur in all male descendants of an affected male.

LESSON 4: BASIC TAXONOMIC CONCEPTS AND PRINCIPLES

Taxonomy branch of science that deals with the naming and classification of organisms Taxonomist biologist who studies taxonomy How did it started? People wanted to organize their world so they began grouping, or classifying everything they saw. They classify organisms that can swim, fly, crawl, walk on four legs, chew their food, swallow food whole, and are toxic. (pero ngayon basis nalang, di na ginagamit) Phylogeny representation of relationships and, therefore, of how organisms evolved from a common ancestor. Shows the tree of life as a product of evolution and the degrees of relationship by descent from a common ancestor. Three forms of Phylogeny Taxon 1 (Monophyletic group) is a taxon that evolved from a single ancestor and includes all descendants of that ancestor. Taxon 2 (Polyphyletic group) descended from two or more different ancestors. Taxon 3 (Polyphyletic group) descended from a common ancestor, but not including all descendants of that ancestors.

Classification arrangement of living things into taxonomic groups.

• The most familiar classification scheme is the taxonomic framework established about 250 years ago (1758) Carolus Linnaeus Father of Taxonomy Swedish Botanist Developed a 7-level (taxa) classification system based on similarities between organisms Hierarchical system of classification Dear - Domain - Eukarya King - Kingdom - Animalia Philip - Phylum - Chordata Came - Class - Mammalia Over - Order - Carnivora For - Family - Canidae Good - Genus - Vulpes Soup - Species - Vulpes vulpes Binomial Nomenclature Bi means "two", Nomen means "name' is a classification system using two names to identify an organism (gumagamit ng two names para mas madaling ma identify) Ex. Canis lupus familiaris genus -species -subspecies only the first letter lang ng name ang naka capital, kahit second name dapat small letter na lahat kapag type written ang scientific name dapat naka italicized kapag hand written may underline dapat Genus Consists of a group of closely related species Always capitalized Species Consists of animals that can mate and produce fertile offspring Always lowercase

LESSON 5: PHYLA UNDER KINGDOM ANIMALIA AND CLASSES UNDER PHYLUM CHORDATA

Kingdom Animalia compost of most complex organisms about 2 million species Has 3 characteristics: Diverse - Animals in Kingdom Animalia is far more diverse than kingdom Plantae Vary in size - organisms under this is arranging under microscopic to the most gigantic creature Heterotrophic/Heterotrophs - they can't produce their own food Is divided into two groups Vertebrates - animals with backbone Has only 1 Phyla which is Phylum Chordata Invertebrates - animals without backbone Has 8 Phyla which are from Phylum Porifera to Phylum Echinodermata Have a 9 Phyla Phylum Porifera pore-bearing organisms they may live single or in colonies Ex. Sponges Phylum Cnidaria poses stinging structures called cnidocytes in their mouth and tentacles most of cnidarians are marines species Ex. Jellyfish and corals Phylum Nematoda derived from a Greek word "Nemos" which means "thread" and includes roundworms Roundworms are cylindrical worms with a finely tapered tail Phylum Annelida derived from a Latin word "Annellus" which means a small ring characterized by ringlike body parts worms with segmented body like bulate and linta Phylum Platyhelminthes also known as flatworms some of them are free living while others are parasitic, living in the bodies of animals including humans Ex. planarian (microscopic organisms) Phylum Mollusca soft bodied animals from Latin term "Mellis" which means soft signifies a soft body, since the earliest descriptions of mollusks came from observations of unshelled cuttlefish the predominant phylum in the marine environment Ex. Octopus, snail, oysters and squid Phylum Arthropoda from the Greek term "Arthron" means joint and "Podus" means foot have a pair of 3 or more jointed legs like butterfly, shrimp,, crabs and bugs have an exoskeleton or hard outer body covering made up of chitin the largest phylum in kingdom animalia Phylum Echinodermata from the Greek terms "Echinos" means hedgehog and "Derma" meaning skin marine organisms with spiny skins like starfish, sea cucumbers and sea urchins Phylum Chordata consist of 5 classes which are: Class pisces or fishes they have scales as body covering and they breathe through their gills they also have lungs for breathing Fishes is divided into 2 groups: Bony fishes/maraming tinik like bangus, lapu-lapu and dalagang bukid Cartilaginous fishes/ like sharks and rays

Class amphibia or amphibians term amphibian loosely translates from the Greek as "Dual life" live in water during the early stage of their life and begin to stay on land where they can get enough food like frogs their eggs are fertilized externally Class reptilia or reptiles have thick, dry scales that cover the bodies of reptiles to prevent the excessive loss of water like pagong and snakes they are cold blooded animals some have four legs, while others have no legs Class aves or birds feathers cover their body they have beaks or bill (tuka) which they use to get foods they have a pair of wings that enable them to fly Class mammalia or mammals covered with hair and they have mammary glands like monkey, lion, giraffe and duck-billed platypus these gland secrete milk of females who have just delivered their young warm-blooded animals

LESSON 6: SYMBIOTIC RELATIONSHIP (SYMBIOSIS)

Symbiosis The act of living together Two organisms that live together Temporarily or for a longer time At least one of the organisms benefits from the relationship Different types of Symbiosis Mutualism Is biological interaction between two species wherein both species benefit from each other. Commensalism Is a symbiotic relationship where one organism benefits and the second is neither harmed nor helped. Parasitism In parasitism, one organism benefits from the relationship at the expense of the other. The parasitic organism may live inside another organism's body (endoparasitism) or on its surface (ectoparasitism) Competition Is when individuals or populations compete for the same resource, and can occur within or between species. Predation Is when one organism eats another organism to obtain nutrients.