2. ___√__ The principle of dominance says that some alleles are dominant while others are recessive

3. ___√__ The Punnett square is used to predict genetic variance

4. _____ Heterozygous means the same, while homozygous means different

5. ____√_ Phenotypes = physical characteristics, Genotypes = genetic characteristics

6. ___√__ Ratios are often expressed as a fraction

7. _____ Incomplete dominance is when both alleles contribute to the phenotype (red flower + white flower = flower with red and white spots)

8. ___√__ The environment can affect genetics

9. _____ Self-pollination occurs when the pollen of one plant attaches to the stigma of another plant

10. __√___ Parents = P generation, offspring = F generationIntroduction to Genetics Lecture Notes<br />Gregor Mendel<br />Worked with common garden peas to study genetics<br />True-breeding plants are plants that, if allowed to self-pollinate, would produce offspring _________________ to themselves<br />To prevent self-pollination, Mendel cut off the male reproductive structure off one plant. He then pollinated the plant with pollen from another plant - __________-pollination<br />Genes and Dominance<br />Mendel studied seven different pea plant traits - a specific characteristic, such as seed color or plant height that varies from one individual to another<br />The original pair of plants are the _____ generation<br />The offspring are called the _______ generation<br />The offspring of crosses between parents with different traits are called ________________<br />Genes and Dominance<br />The F1 generation had the character of only of the parents<br />Mendel drew two conclusions<br />Biological inheritance is determined by factors that are passed from generation to the next<br />The principle of dominance - some alleles are ________________and others are _______________<br />Genes are _____________ factors that determine traits<br />Alleles are different ___________ of the __________<br />Segregation<br />Had the recessive alleles disappeared, or were they still present in the F1 plants?<br />He allowed the F1 plants to self-pollinate to produce the F2 generation, in which all of the recessive alleles had reappeared<br />When each F1 plant flowers and produces gametes, the two alleles segregate from each other so that each gamete carries only a single copy of each gene. Therefore, each F1 plant produces two types of gametes - those with alleles for tallness and those with the allele for shortness<br />Genetics and Probability<br />The ____________________ that a particular event will occur is called probability<br />The principles of probability can be used to predict the outcomes of genetic crosses<br />Punnett Squares<br />The Punnett square can be used to predict and compare the genetic variations that will result from a cross<br />Homozygous means that the organism has two _____________ alleles for a particular trait<br />Heterozygous mean that the organism has two ______________alleles for a particular trait<br />Phenotypes are ________________characteristics<br />Genotypes are _________________ characteristics<br />Probability and Segregation<br />For each of Mendel’s seven crosses, ¾ of the plants showed the trait controlled by the dominant allele, while ¼ of the plants showed the trait controlled by the recessive trait - a ________ ratio<br />Probabilities predict the average outcome of a large number of events - the larger the number of offspring, the closer the resulting numbers will get to expected values<br />The Two Factor Cross: F1<br />Two different genes passing from generation to another<br />First, Mendel crossed tree-breeding plants (RRYY x rryy)<br />All of the F1 offspring produced the dominant genes<br />The Two Factor Cross: F2<br />Mendel knew that all the F1 plants were heterozygous for both genes<br />The F2 generation shows how alleles segregate<br />Since the alleles for both genes segregated independently of each other (independent assortment), the ratio was _____________<br />The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. Independent assortment helps account for the many genetic variations observed in plants, animals, and other organisms<br />Summary of Mendel’s Principles<br />The inheritance of biological characteristics is determined by individual units known as genes. Genes are passed from parents to their offspring<br />In cases in which two or more alleles of the gene for a single trait exist, some forms of the gene may be dominant and others may be recessive<br />In most sexually reproducing organisms, each adult has two copies of each gene - one from each parent. These genes are segregated from each other when gametes are formed<br />The alleles for different genes usually segregate independently of one another<br />Incomplete Dominance<br />Cases in which one allele is ___________completely dominant over another <br />The heterozygous phenotype is somewhere between the two homozygous phenotypes<br />Codominance<br />Both alleles contribute to the _________________<br />Multiple Alleles<br />Many genes have more than two alleles<br />This does not mean that an individual can have more than two alleles, it only means that more than two possible alleles exist in a population<br />Polygenic Traits<br />Traits controlled by two or more genes are said to be _________________ traits<br />Genetics and the Environment<br />The characteristics of any organism are not determined solely by the genes it inherits, but by interaction between genes and the ____________________<br />Genes provide a plan for development, but how that plan unfolds also depends on the environment<br />