Genetics Vocabulary Review What is a trait A

Genetics

Vocabulary Review • What is a trait? ? ? -A physical characteristic. • What is heredity? ? ? -The passing of traits from parents to offspring. • What is genetics? ? ? - The scientific study of heredity. 3/12/2021 Free template from www. brainybetty. com 2

Question #1 Which of the following is an example of a trait? A. Bb B. Talking loud C. Brown eyes D. Bleach blonde hair 3/12/2021 Free template from www. brainybetty. com 3

Alleles • Genes are the factors that control Traits. • Alleles are the different forms of Genes. Example: pea plants • Individual Alleles control the inheritance of Traits. • An offspring receives one allele from each parent. 3/12/2021 Free template from www. brainybetty. com 4

Question #2 What is the term for factors that control traits? A. Genes B. Purebreds C. Recessives D. Parents 3/12/2021 Free template from www. brainybetty. com 5

Question #3 Which term refers to physical characteristics that are studied in genetics? A. Traits B. Offspring C. Generations D. Hybrids 3/12/2021 Free template from www. brainybetty. com 6

DOMINANT and recessive Alleles • A dominant allele is one whose trait always shows up in an organism when the allele is present. - represented by a capital letter. • A recessive allele is covered up when the dominant allele is present. - represented by a lower case letter. 3/12/2021 Free template from www. brainybetty. com 7

Practice • R is the dominant allele for a one eyed monster. • r is the recessive allele for a monster with two eyes. 3/12/2021 Free template from www. brainybetty. com 8

Monster Genetics • Rr • How many eyes will our monster have? ? ? 3/12/2021 Free template from www. brainybetty. com 9

Monster Genetics • RR • How many eyes will our monster have? ? 3/12/2021 Free template from www. brainybetty. com 10

Monster Genetics • rr • How many eyes will our monster have? ? 3/12/2021 Free template from www. brainybetty. com 11

#4 What does the notation TT mean to geneticists? A. Two dominant alleles B. Two recessive alleles C. No dominant alleles D. One dominant and on recessive allele 3/12/2021 Free template from www. brainybetty. com 12

Codominance • In Mendel’s studies he found some alleles to be neither dominant or recessive. • Codominance is when alleles are neither dominant or recessive and as a result both alleles are expressed in the offspring. 3/12/2021 Free template from www. brainybetty. com 13

What will Happen? • You have two flowers, a white and a red, that are crossed. • The flowers are codominant. • What color will their offspring be. 3/12/2021 Free template from www. brainybetty. com 14

End Day 1 3/12/2021 Free template from www. brainybetty. com 15

Phenotype • Phenotype and genotype are words that scientist use to describe organisms. • Phenotype is an organisms physical appearance or its visible traits. • Example: a pea plant can have one of two phenotypes for stem height-short or tall. 3/12/2021 Free template from www. brainybetty. com 16

Genotype • Phenotype and genotype are words that scientist use to describe organisms. • Genotype is an organisms genetic makeup, or allele combination. • Genotype TT=tall (Phenotype) 3/12/2021 Free template from www. brainybetty. com 17

Describing genotypes • Scientist use the words heterozygous and homozygous to describe genotypes. • Homozygous is used to describe an organism that has two identical alleles for a trait. • Example: PP and pp • Heterozygous is used to describe an organism with two different alleles. -Also called hybrid. • Example: Tt 3/12/2021 Free template from www. brainybetty. com 18

#9 Green seed color (G) is dominant to yellow seed color (g). If two heterozygous parents are crossed, what will be the resulting genotypes of the offspring? A. GG, Gg, gg B. Gg, gg C. GG, Gg D. gg, GG 3/12/2021 Free template from www. brainybetty. com 19

#5 Pick the answer that best describes “AA”. A. Homozygous B. Heterozygous 3/12/2021 Free template from www. brainybetty. com 20

#8 According to Mendel, red flower color (R) is dominant over white flower color (r). If a heterozygous parent is crossed with a homozygous recessive parent, which of the following would be true? A. All four “rr” B. All four “Rr” C. Two “rr” and two “Rr” D. Two “rr” and two “RR” 3/12/2021 Free template from www. brainybetty. com 21

#6 Pick the answer that best describes “Aa”. A. Homozygous B. heterozygous 3/12/2021 Free template from www. brainybetty. com 22

Probability • Probability is the likelihood that a particular event will occur. • Probability predicts what will occur, and is not always necessarily what will occur. • Example: if you toss a coin there is a fifty percent chance the coin will land on heads, and fifty percent the coin will land on tails. 3/12/2021 Free template from www. brainybetty. com 23

Mendel and Probability • Mendel was the first scientist to recognize that the principles of probability can be used to predict the results of genetic crosses. • Mendel could predict the probability of producing a tall or short pea plant. 3/12/2021 Free template from www. brainybetty. com 24

Punnett Squares • A punnett square is a chart that shows all possible combinations of alleles that can result from a genetic cross. 3/12/2021 Free template from www. brainybetty. com 25

Punnett Example • Yellow is dominant over Green. • What is the probability that the offspring will be yellow? 100% 3/12/2021 Free template from www. brainybetty. com 26

Punnett Problems • In purple people eaters, one-horn is dominant and no horns is recessive. • Draw a Punnet Square showing the cross of a purple people eater that is hybrid for horns, with a purple people eater that does not have horns. 3/12/2021 Free template from www. brainybetty. com 27

Answer • Hybrids have two different alleles for one trait. • Hh is the hybrid in the example. • No horns would have to be hh because it is a recessive allele. 3/12/2021 Free template from www. brainybetty. com 28

Punnett Problems • In Bears the recessive allele for brown fur is R, black fur is recessive. • The female bear is Rr and the male bear is rr. • What are the four possible phenotypes for the cubs. • What is the probability that the cub will have black fur? 3/12/2021 Free template from www. brainybetty. com 29

Answer • The four possible phenotypes would be 2(black) and 2(brown). • There would be a fifty percent chance the cub would be brown and fifty percent chance the cub would be black. 3/12/2021 Free template from www. brainybetty. com 30