Genetics and Inheritance Study Guide PDF

Genetics and Inheritance Study Guide DNA Fundamentals DNA Structure Molecular Composition ○ Deoxyribonucleic Acid (DNA) shaped like a double helix ○ Resembles a twisted ladder structure ○ Composed of nucleotides with 3 key components: 1. Sugar...

Genetics and Inheritance Study Guide DNA Fundamentals DNA Structure Molecular Composition ○ Deoxyribonucleic Acid (DNA) shaped like a double helix ○ Resembles a twisted ladder structure ○ Composed of nucleotides with 3 key components: 1. Sugar 2. Phosphate 3. Base Nucleotide Base Pairing Base Types: 4 fundamental bases ○ A (Adenine) ○ T (Thymine) ○ C (Cytosine) ○ G (Guanine) Specific Pairing Rules ○ A connects with T ○ C connects with G ○ Bases held together by hydrogen bonds Genetic Code Characteristics Universal across organisms Base sequence determines protein instructions Entire DNA code present in nearly all body cells Approximately 20,000-25,000 genes in humans Genes and Inheritance Gene Basics Definition: Small DNA portion coding for proteins Humans receive 23 genes from each parent Inheritance is random Allele Concepts Allele: Specific identified gene version Genotype: Set of alleles for a trait Phenotype: Physical trait manifestation Inheritance Patterns 1. Complete Dominance ○ Dominant allele always expressed ○ Represented by capital letters ○ Recessive allele "hidden" 2. Incomplete Dominance ○ Alleles "blend" together ○ Neither allele is completely dominant 3. Co-dominance ○ Both alleles expressed separately in phenotype Mutations Types of Mutations Inherited Mutation ○ Occurs during fertilization ○ Affects all body cells Acquired Mutation ○ Result of environmental factors ○ Affects specific cells ○ Can alter gene expression without changing DNA sequence Protein Dynamics Protein Characteristics Large molecules performing critical body functions Composed of amino acids Involved in: ○ Transport ○ Structural support ○ Enzymatic processes ○ Body protection Protein Mutation Example  Hemophilia ○ Caused by missing blood clotting protein ○ Can be treated via protein injection Advanced Genetic Regulation Gene Regulation Mechanisms Genes can be turned on/off Critical for maintaining bodily homeostasis Involves complex cellular interactions Chromosomal Insights Human Chromosome Overview 46 total chromosomes 23 chromosome pairs Genetic code contained within these structures Key Inheritance Principles Trait Transmission Traits influenced by: ○ Genetic code ○ Environmental conditions Each trait has specific inheritance pattern Variation Principles Genetic differences between individuals Random gene transmission from parents Mutation and Genetic Therapy Modern Genetic Interventions Gene therapy focuses on: ○ Fixing genetic issues ○ Replacing problematic genes  Potential to inject human genes into other organisms Important Terminology Table Term Definition Example Gene = DNA segment coding = Height gene proteins Allele = Specific gene version = Blue eye gene Phenotype = Observable trait = Eye color Genotype = Genetic combination = Bb (for eye color) Part 2 Notes: Genes and Heredity Genes are small sections of DNA that code for proteins. Heredity is the study of how genes are passed from parents to offspring. Traits are characteristics of an organism, coded by DNA. Traits can be influenced by environmental factors like UV light. DNA Structure and Function DNA determines characteristics like height and eye color. DNA is found in almost all cells excluding sex cells. DNA in sex cells has half the DNA of parent cells. DNA is a double helix, shaped like a twisted ladder. DNA bases (adenine, thymine, cytosine, guanine) pair specifically. Nucleotides (sugar, phosphate, base) are the building blocks of DNA. Reproduction Asexual reproduction: offspring inherit all DNA from one parent. Sexual reproduction: offspring inherit DNA from two parents. Traits and Inheritance Traits are influenced by genes. Each gene can have different forms (alleles). Dominant alleles always show in the phenotype. Recessive alleles only show in the phenotype if two copies are present. Genotype: the combination of alleles for a trait. Phenotype: the physical expression of a trait. Variation exists in traits between organisms. Genes, Proteins, and Traits Genes code for proteins. Proteins have various roles in an organism's structure, function, and actions. Specific arrangement of proteins affects trait expression. Gene activity can be regulated. Chromosomes Chromosomes are a tightly organized form of DNA. Humans have 46 chromosomes (23 pairs). The sequence of bases in DNA distinguishes one organism from another. Inheritance Patterns Complete dominance: one allele hides the other. Incomplete dominance: alleles blend to form a new phenotype. Codominance: both alleles are expressed in the phenotype. Mutations Mutations are changes in the DNA code. Mutations can be inherited or acquired. Protein Molecules Proteins have many roles and are made of amino acids. Clotting factors are proteins important in blood clotting. Hemophilia Hemophilia is a disease where a protein needed for blood clotting is missing. People with hemophilia can be treated through the injection of clotting factors. Gene Therapy Gene therapy aims to fix or replace genes. Part 3 Notes: Genes and Heredity Genes are sections of DNA that code for proteins, essential for processes like cell signaling, metabolism, and structure. Heredity studies how genes are passed from parents to offspring, leading to unique traits and genetic diversity. Traits are characteristics influenced by DNA and environmental factors (e.g., sunlight affecting melanin production). DNA Structure and Function DNA, primarily in the nucleus, acts as the blueprint for traits and proteins. It is structured as a double helix, with base pairs (A-T, C-G) enabling accurate replication. DNA in reproductive cells (gametes) is halved to maintain chromosome count during fertilization. DNA is composed of nucleotides (sugar, phosphate, nitrogenous base), which encode genetic information. Reproduction Asexual reproduction creates identical offspring from one parent, while sexual reproduction combines genes from two parents, fostering genetic diversity. Traits and Inheritance Traits result from the interplay of genes and the environment. Alleles (gene variants) influence traits through dominance (e.g., dominant vs. recessive). Genotype determines the genetic makeup, while phenotype is the observable expression of traits. Genes, Proteins, and Traits Genes encode proteins that catalyze reactions, provide structural support, and regulate processes. Protein structure, dictated by amino acid sequences, influences traits. Chromosomes Humans have 46 chromosomes (23 pairs), inheriting one set from each parent. Chromosomes ensure accurate genetic transmission during cell division. Inheritance Patterns Complete dominance: One allele masks another. Incomplete dominance: Blended traits (e.g., pink flowers). Codominance: Both alleles are equally expressed (e.g., AB blood type). Mutations Mutations are changes in DNA, caused by replication errors or environmental factors, which can lead to genetic disorders or evolution. Proteins and Hemophilia Proteins, made of amino acids, perform critical roles (e.g., clotting factors for blood coagulation).  Hemophilia, an X-linked disorder, affects clotting and is treated with clotting factor concentrates or gene therapy. Gene Therapy Gene therapy targets defective genes to correct or replace them, offering potential cures for genetic disorders and diseases. Part 4 Notes: Video Notes Gene: A small portion of DNA that codes for proteins Heredity: the study of how genes are passed down from parents to offsprings. Dna, Chromosome, Genes, and traits Traits Traits are coded by DNA Traits are affected by environmental conditions, UV lights Traits: a specific characteristic of a specific organism(specific to a person) Eg; Someone is very tall is a trait, height isn’t a trait Axsexual reproduction: When an organism doesn’t need a mate to produce offspring. The main diffrensce between asxesual reproduction and sexual reproduction is that asexsual reproduction offspring get all of their DNA from one parent. Nuclei is plural of nucleus and they hold dna DNA determines;: How tall you are, your eye color and many more Entire dna code in your body cells, almost all the cells hold almost all your DNA with the exception of your sex cell (contains half of your DNA and half of your partners) DNA strands for Deoxyribonucleic Acid Feature: A characteristic that most ort all of a species have Eg; Height Building blocks of DNA are nucleotides. Nucleotides have 3 parts Sugar, phosphate, and base 4 types of bases in dna, ATCG A = adenine T = Thymine C = Cytosine G = Guanine These bases pair together in a specific way. A connects with T C connects with G Dna bases are the same for all organisms. The amount of dna bases and the sequences they connect differ per species Dna has two strands and bases are held together by hydrogen bonds Bases form a code and that code instructs how to make proteins Dna is shaped double helix, looks like a twisted ladder Genes code for proteins Genes can code for proteins that are a certain color and when all the proteins are combined eye color or something else is made Proteins are involved in transport, structure acting in enzymes and protecting the body THeir are parts of DNA that don't code Gene Regulation: Genes can be turned on and turned off by multiple mechanisms Gene regulation is one of the main ways for your body to maintain homeostasis When dna is compacted it can become a unit called a chromosome Chromosome: A large portion of compacted DNA that contain many genes Humans have 46 Chromosomes Humans have 23 pairs of chromosomes Humans have approximately 20,000- 25,000 Humans get 23 genes from each parents Nearly every body cell in your body has 46 chromosomes 46 chromosomes is your genetic code The sequence of bases are difference in the code of your DNA Variation: any difference in traits between individual organisms Organisms get 1 gene from each parent per trait Eg; a spider gets 1 gene from his dad and one gene from his mom for spider flexibility. Its random what gene gets passed on from parent to offspring Sugar and phosphate make up the backbone of your DNA Each gene CODES for proteins The bases are the instructions The sequence of the bases matter The cell will read the code to know what protein to make Each protein molecule is a puzzle piece Proteins are shaped in a way so that they can ONLY connect one way GENE->CODE->CELL->PROTEIN->STRUCTURE = TRAIT Traits Lecture Notes Gene is a small portion of DNA that codes for a protein We get two genes for each trait, one from mom and one from dad Its random which of the two genes you will inherit from your parents Allele: an identified, specific gene (you know what protein molecule it codes for) When written can be represented by a single letter As soon as you know what protein molecule a gene codes for, it turns into an Allele Any single letter can be used to represent an Allele Genotype: A set of alleles for a particular trait (are written down as two letters, one for each allele) Phenotype: the physical outcome of the genotype (what shows) Eg; if genotype codes for blue eye proteins, blue eyes would be the Phenotype Dominant trait: A trait that will always show in the phenotype as long as there's at least 1 dominant allele in the genotype (More common in a population) Eg; brown eyes is a dominant trait in human beings Dominant allele: Codes for a dominant trait protein molecule. When written, it will always be capitalized and comes first in a genotype. Recessive trait - A trait that requires two of the same recessive alleles in order to show in a phenotype. Less common Recessive allele: Codes for a recessive trait’s protein molecule. Will always be written as a lowercase letter Heterozygous genotype:The alleles of a genotype are different Homozygous genotype: When the alleles of a genotype are the same Inheritance Pattern- The way phenotypes show based on the alleles in the genotype. Each trait has its own inheritance pattern and they do not change from individual to individual. Eg; Whatever inheritance pattern is used to determine your dog’s fur color is the same on that determines every dog’s fur color Complete Dominance: when a genotype contains both dominant and recessive alleles, the recessive alleles gets “hidden”, and only the dominant allele will show in the phenotype. This is the standard inheritance pattern, and it supersedes all others. (if there is one dominant and one recessive allele, it automatically become this inheritance pattern) Incomplete Dominance: If there are two different dominant alleles in the genotype, the alleles will “blend” together Co-dominance: If there are two different dominant alleles in the genotype BaOTH alleles will show separately in the phenotype. Adding in more of the same protein you already have does not change the trait Adding in a new protein can change the trait, depending on if its dominant or recessive Mutation Notes Mutation- Any change in a gene, or how the gene is read The bases are the code, when talking about the change in a gene, we are talking about the bases Inherited Mutation- Any mutation given to you during fertilization (affects all cells) Acquired Mutation- You get as a result of environmental factors or errors in DNA duplication (only affects some cells). Some environmental factors alter how genes are read without changing the DNA sequence itself. Article Notes Protein molecules- A large molecule that performs important functions in the human body, made of amino acids Blood includes 13 different protein molecules called clotting factors Clotting factors work together to form scabs, to stop bleeding after you get injured, if you are missing on clotting factors the clot won't form Hemophilia- is a disease where a person is missing one of the proteins needed for blood clotting. Function- How something works gene version- a specific form of protein that provides instructions for making a particular protein molecule AKA Allele Traits are determined by proteins People with hemophilia can cursive by getting clotting factors injected into their blood. Nucleus- Part of the cell where genes are found Scientists can inject human genes into hamsters and the hamsters’ cells will start making that protein As long as the cell has the gene with instructions for making clotting factor protein, the cell will make the protein. Working to fix or replace genes is called gene therapy