$200 $300 $400 $500 $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 $100 Vocabulary 1 Mendel’s Peas Punnett Squares General Genetics Vocabulary 2

a section of DNA that has information about a specific trait of an organism

gene

alleles that make up an organism

genotype

alleles that produce a phenotype that is a blended form of the parents’ phenotypes

incomplete dominance

a genetic or chromosomal mutation that is inherited

genetic disorder

the study of how traits of organisms are passed from parents to offspring

genetics

What plant did Mendel use for his experiments and what were the seven traits he studied?

Pea plants: flower color, flower position, seed color, seed shape, pod shape, pod color, stem length

Why were these plants a good choice for conducting genetic experiments?

Easy to grow, they flower and reproduce quickly, they come in many varieties, each trait has only two variations.

Suppose you crossed a heterozygous yellow pea plant with a green pea plant. What are the possible genotypes and phenotypes of the offspring?

Genotypes: Yy, yy Phenotypes: yellow, green

What does Mendel’s Law of Segregation state?

Two factors for each trait separate from each other during meiosis.

What does Mendel’s Law of Independent Assortment state?

Factors for one trait separate independently of the ways that factors for other traits separate.

Make a Punnett square to cross a homozygous yellow pea plant with a green pea plant. Predict the percentage of offspring to have a genotype of YY, Yy, yy and phenotype of green seeds and yellow seeds.

YY y y Yy YY = 0%, Yy = 100%, yy = 0% Yellow = 100 %, Green = 0%

Make a Punnett square to cross two heterozygous free earlobe parents. What is the probability an offspring will have free earlobes? What is the probability an offspring will have attached earlobes?

Ff F f FF Ff ff Free earlobes = 75%, attached earlobes = 25%

Make a Punnett square to cross a male with a female that is a carrier for color blindness. What is the probability that the males will be color-blind? What is the probability that the females will be color-blind?

XY XcXc X X X c XcYXcY X XY Color-blind males = 25%, Color-blind females = 0%

Cross two heterozygous black guinea pigs. What is the probability that an offspring will have black fur? What is the probability that an offspring will have white fur?

B B b b BB Bb bb black fur? 75% white fur? 25%

Cross a homozygous round seed plant with a wrinkled seed plant. What is the probability that an offspring will have round seeds? What is the probability that an offspring will have wrinkled seeds?

R r R r Rr round seeds? 100% wrinkled seeds? 0%

Who was Gregor Mendel and why is he important?

The first person known to record evidence that traits of organisms are determined by factors passed from parents to offspring. All the research of modern genetics is based on Mendel’s conclusions from his work with pea plants.

When a pair of chromosomes contains different alleles for a trait, that trait is called a(n) _____; when a trait has two identical alleles, it is called _____.

heterozygous homozygous

In a Punnett square, a capital letter stands for a _____ allele.

dominant

Of the following, which represents a homozygous recessive genotype? TT, Tt, tt, TTT

tt

Blood types in humans are controlled by _____ alleles. Name the 4 human blood groups.

multiple A, B, AB, O

a genetic factor that is hidden by the presence of a dominant factor

recessive

the two factors for each trait segregate or separate from each other during meiosis when gametes form

Law of segregation

each form of a gene with different information

allele

two alleles for a gene having the same information

homozygous

model used to predict possible genotypes and phenotypes of offspring

Punnett square