Results for "incomplete dominance"

Incomplete Dominance & Codominance

2 - "Non" Mendelian Genetics - Codominance, Incomplete Dominance, etc., and Linkage

Dominance: Incomplete Dominance, Codominance and Overdominance

topic 8 genetics

Sex-Linked Traits, Codominance + Incomplete dominance

The Secret of Life Walter Sutton 1902 Chromosome theory: Genes are located on chromosomes, each gene occupies a specific place (locus) on a chromosome. A gene may exist in several forms (alleles) but each chromosome has just one allele for each gene. Mendel says traits controlled by genes, said they come in contrasting forms - differences in genetic sequence difference. Differences Genes: Mendel - Genes come in contrasting forms Theory - Simply minor changes in nitrogenous bases Dominance & Recessiveness Mendel: Some alleles are or are not expressed. Theory: Dominant Allele codes for function of protein, recessive doesn’t. Segregation Mendel: All plants have two alleles for every trait. Theory: Plants had two chromosomes, which come in pairs. Independent Assortment: Mendel: Segregation of one allele has nothing to do with segregation for other genes. Theory: Separation of chromosomes and chromatids is independent of others in meiosis. Genes on the same chromosome are said to be linked Linked genes are inherited together. They do not undergo independent assortment. Mendel was lucky he had chosen traits from different chromosomes. Thomas Hunt Morgan Fruit flies are ideal for genetic studies. He found that the gray body is dominant to black. Normal wings are dominant to small. Morgan’s Experiment: Crossed purebred gray normal wing flies (GGWW) with purebred black small wing flies (ggww) In F1, all are gray with normal wings (GgWw) He does not go to F2, but he takes F1 and does a test cross. He crossed something with a homozygous recessive. Results: 25% of each, 41.5 GW, 41.5 gw, 8.5 gW, 8.5 Gw X^2 is 43.56 at 3 df Conclusion: The two genes are linked/connected. They do not assort independently. They are on the same chromosome. Linkage Groups Groups of genes that tend to be inherited together. Fruit flies have 4 linkage groups. Fruit flies have 4 pairs of chromosomes. Corn has 10 linkage groups. Corn has 10 pairs of chromosomes. What about the 17% that did assort independently? Crossing over - most have blonde hair blue eyes, but crossing over can create blonde hair brown eyes. Produces individuals with rearranged linkage groups - “Recombinants” Frequency of crossing-over can be used to “map” genes. Sex Determination Autosomes - homologous pairs of chromosomes. Sex chromosomes Not necessarily homologous - X or Y Determines the sex of an individual XX = female XY = male Cannot live without X Sex-linkage Genes on the sex chromosome are “sex-linked” Usually on the X chromosome. Recessive X-linked traits are more often expressed in males. Morgan’s Experiment The gene for eye color is located on the X chromosome. Red eye color is dominant to white. Crossed white eyed male (XrY) with homozygous red eye female (XrXr) Conclusion: All F1 had red eyes - XRXr or XRY Gene Interactions Incomplete Dominance Active allele does not completely compensate for an inactive allele Carnations Red x White → Pink Pink X Pink → 1 Red, 2 Pinks, 1 White Codominance Both alleles are expressed. Cattle White X Red → Roan Roan X Roan → 1 Red, 2 Roan, 1 White Polygenic Inheritance Trait is controlled by many genes Tends to follow a gradient, not either/or Ex

The Secret of Life Walter Sutton 1902 Chromosome theory: Genes are located on chromosomes, each gene occupies a specific place (locus) on a chromosome. A gene may exist in several forms (alleles) but each chromosome has just one allele for each gene. Mendel says traits controlled by genes, said they come in contrasting forms - differences in genetic sequence difference. Differences Genes: Mendel - Genes come in contrasting forms Theory - Simply minor changes in nitrogenous bases Dominance & Recessiveness Mendel: Some alleles are or are not expressed. Theory: Dominant Allele codes for function of protein, recessive doesn’t. Segregation Mendel: All plants have two alleles for every trait. Theory: Plants had two chromosomes, which come in pairs. Independent Assortment: Mendel: Segregation of one allele has nothing to do with segregation for other genes. Theory: Separation of chromosomes and chromatids is independent of others in meiosis. Genes on the same chromosome are said to be linked Linked genes are inherited together. They do not undergo independent assortment. Mendel was lucky he had chosen traits from different chromosomes. Thomas Hunt Morgan Fruit flies are ideal for genetic studies. He found that the gray body is dominant to black. Normal wings are dominant to small. Morgan’s Experiment: Crossed purebred gray normal wing flies (GGWW) with purebred black small wing flies (ggww) In F1, all are gray with normal wings (GgWw) He does not go to F2, but he takes F1 and does a test cross. He crossed something with a homozygous recessive. Results: 25% of each, 41.5 GW, 41.5 gw, 8.5 gW, 8.5 Gw X^2 is 43.56 at 3 df Conclusion: The two genes are linked/connected. They do not assort independently. They are on the same chromosome. Linkage Groups Groups of genes that tend to be inherited together. Fruit flies have 4 linkage groups. Fruit flies have 4 pairs of chromosomes. Corn has 10 linkage groups. Corn has 10 pairs of chromosomes. What about the 17% that did assort independently? Crossing over - most have blonde hair blue eyes, but crossing over can create blonde hair brown eyes. Produces individuals with rearranged linkage groups - “Recombinants” Frequency of crossing-over can be used to “map” genes. Sex Determination Autosomes - homologous pairs of chromosomes. Sex chromosomes Not necessarily homologous - X or Y Determines the sex of an individual XX = female XY = male Cannot live without X Sex-linkage Genes on the sex chromosome are “sex-linked” Usually on the X chromosome. Recessive X-linked traits are more often expressed in males. Morgan’s Experiment The gene for eye color is located on the X chromosome. Red eye color is dominant to white. Crossed white eyed male (XrY) with homozygous red eye female (XrXr) Conclusion: All F1 had red eyes - XRXr or XRY Gene Interactions Incomplete Dominance Active allele does not completely compensate for an inactive allele Carnations Red x White → Pink Pink X Pink → 1 Red, 2 Pinks, 1 White Codominance Both alleles are expressed. Cattle White X Red → Roan Roan X Roan → 1 Red, 2 Roan, 1 White Polygenic Inheritance Trait is controlled by many genes Tends to follow a gradient, not either/or Ex

Let’s break this down! I’ll give you a study guide covering asexual reproduction, sexual reproduction (in humans and plants), and Mendelian genetics — then I’ll create a test for you. ⸻ Study Guide for Asexual Reproduction, Sexual Reproduction, and Mendelian Genetics ⸻ I. Asexual Reproduction • Definition: Involves a single parent, producing offspring genetically identical to the parent (clones). • Types of Asexual Reproduction: • Binary Fission: Simple cell division (e.g., bacteria). • Budding: New organism grows from a bud on the parent (e.g., yeast, hydra). • Fragmentation/Regeneration: Organism splits, and each part grows into a new organism (e.g., starfish). • Vegetative Propagation: New plants grow from parts of the parent plant (e.g., runners in strawberries). • Parthenogenesis: Offspring develop from unfertilized eggs (e.g., some lizards, insects). • Pros and Cons: • Pros: Fast, no need for a mate, energy-efficient. • Cons: No genetic variation, susceptible to environmental changes. ⸻ II. Sexual Reproduction (Humans & Plants) Humans: • Process: • Gametes (sperm and egg) produced by meiosis. • Fertilization forms a zygote (diploid cell). • Male Reproductive System: Testes, epididymis, vas deferens, prostate, urethra, penis. • Female Reproductive System: Ovaries, fallopian tubes, uterus, cervix, vagina. • Hormonal Regulation: • Male: Testosterone (sperm production, secondary characteristics). • Female: Estrogen & progesterone (menstrual cycle, pregnancy). Plants: • Process: Alternation of generations (sporophyte & gametophyte stages). • Pollination: Transfer of pollen to stigma. • Fertilization: Sperm (from pollen) fuses with egg in ovule. • Structures: Stamen (male), carpel/pistil (female). • Seed & Fruit Development: Fertilized ovules become seeds; ovary becomes fruit. ⸻ III. Mendelian Genetics • Gregor Mendel’s Experiments: Pea plants, discovered inheritance patterns. • Key Concepts: • Genes & Alleles: Genes determine traits, alleles are gene variants. • Dominant vs. Recessive Alleles: Dominant alleles mask recessive ones. • Homozygous vs. Heterozygous: Same alleles (AA or aa) vs. different alleles (Aa). • Laws of Inheritance: • Law of Segregation: Allele pairs separate during gamete formation. • Law of Independent Assortment: Genes for different traits sort independently. • Genetic Crosses: Punnett squares, monohybrid/dihybrid crosses. • Probability & Ratios: Phenotypic/genotypic ratios. • Non-Mendelian Inheritance: Incomplete dominance, codominance, multiple alleles, polygenic traits, sex-linked traits. ⸻ AP Biology Practice Test Total Questions: 30 (Multiple Choice) Section 1: Asexual Reproduction (6 questions) 1. Which form of asexual reproduction involves an organism splitting into two identical cells? a) Budding b) Fragmentation c) Binary fission d) Parthenogenesis 2. Which organism commonly reproduces through budding? a) Bacteria b) Starfish c) Hydra d) Fern 3. A disadvantage of asexual reproduction is: a) Slow reproduction rate b) High genetic diversity c) Vulnerability to environmental changes d) Requirement of a mate 4. Which plant structure is involved in vegetative propagation? a) Petal b) Stigma c) Runner d) Anther 5. Parthenogenesis involves: a) Fertilized eggs developing into offspring b) Unfertilized eggs developing into offspring c) Fusion of gametes d) Regeneration of lost body parts 6. What is the primary benefit of asexual reproduction in stable environments? a) Genetic variation b) Rapid population growth c) Evolutionary adaptability d) Reduced mutation rates ⸻ Section 2: Sexual Reproduction (8 questions) 7. In humans, fertilization typically occurs in the: a) Uterus b) Vagina c) Ovary d) Fallopian tube 8. The male gamete in plants is contained in the: a) Ovule b) Anther c) Pollen grain d) Stigma 9. Which hormone triggers ovulation? a) Testosterone b) Progesterone c) Luteinizing hormone (LH) d) Estrogen 10. The female gametophyte in flowering plants is the: a) Ovary b) Pollen tube c) Embryo sac d) Sepal 11. Which part of the male reproductive system produces sperm? a) Epididymis b) Vas deferens c) Testes d) Prostate gland 12. The process where pollen is transferred from anther to stigma is: a) Germination b) Pollination c) Fertilization d) Sporulation 13. What structure develops into a seed after fertilization in plants? a) Ovule b) Ovary c) Stamen d) Pistil 14. Which term describes the fusion of egg and sperm to form a zygote? a) Gametogenesis b) Meiosis c) Fertilization d) Pollination ⸻ Section 3: Mendelian Genetics (16 questions) 15. Who is considered the “Father of Genetics”? a) Charles Darwin b) Gregor Mendel c) Rosalind Franklin d) James Watson 16. The physical expression of a trait is called: a) Genotype b) Phenotype c) Allele d) Chromosome 17. An organism with the genotype Aa is: a) Homozygous dominant b) Homozygous recessive c) Heterozygous d) Diploid 18. A Punnett square shows: a) The process of DNA replication b) Possible genetic combinations of offspring c) Chromosome number in gametes d) Evolutionary relationships 19. The expected phenotypic ratio for a monohybrid cross is: a) 1:2:1 b) 9:3:3:1 c) 3:1 d) 4:0 20. Which of Mendel’s laws states that allele pairs separate during gamete formation? a) Law of Independent Assortment b) Law of Segregation c) Law of Dominance d) Law of Inheritance 21. Incomplete dominance results in: a) Blended traits b) Both traits expressed equally c) One trait completely masking another d) A 9:3:3:1 ratio 22. A cross between two heterozygous individuals (Aa x Aa) produces what genotypic ratio? a) 3:1 b) 1:2:1 c) 9:3:3:1 d) 2:2 23-30

Lecture 11: Dihybrid cross, incomplete dominance, codominance

Incomplete dominance and Co-Dominance

incomplete dominance quiz thing

Bio Quiz 1 Unit 3: complete dominance, incomplete dominance, codominance, sex linked diseases, blood types, gel interpretation, and pedigrees

Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis!

Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis

Incomplete Dominance and Codominance

Co-Dominance and Incomplete Dominance in Genetics

s2 - incomplete dominance + co-dominance (check rest of notes)

Incomplete dominance ( 画到F1) (copy)

Genetic - Extensions to Mendel: Incomplete dominance and multiple alleles

Incomplete Dominance