Once Upon A Time…and Happily Ever Afters:

A Review of the Fundamentals of Genetics

Pinocchio: Truths and Tales

Truth or Tale

Mendel discovered predictable patterns in the inheritance of traits.

Truth

Truth or Tale

Plants in Mendel’s P generation were all heterozygous.

Tale…Homozygous

Truth or Tale

A dominant allele masks or hides the effect of a recessive allele.

Truth

Truth or Tale

A Mendelian factor is equivalent to an allele.

Truth

Truth or Tale

Heterozygous individuals have two of the same alleles for a particular gene.

Tale…different

Truth or Tale

A Punnett square represents the phenotype of an organism.

Tale…genotype

Truth or Tale

A probability of 1/4 is equal to a probability of 75 percent.

Tale…25%

Truth or Tale

The dominant allele for tallness in pea plants is represented by the letter t.

Tale…T

Truth or Tale

•Mendel performed 82 crosses and documented all his results.

Tale…hundreds

Truth or Tale

Genetics is the branch of biology that involves the study of how different traits are transmitted from one generation to the next.

Truth

Mirror Mirror on the Wall,

Who Is the Fairest of Them All?

The scientific study of heredity is calleda. meiosis. c. genetics.b. crossing-over. d. pollination.

Who Is the Fairest of Them All?

C

Mendel obtained his P generation by allowing the plants toa. self-pollinate. c. assort independently.

b. cross-pollinate. d. segregate.

Who Is the Fairest of Them All?

A

What is the probability that the offspring of a homozygous dominant individual and a homozygous recessive individual will exhibit the dominant phenotype?a. 0.25 c. 0.75b. 0.5 d. 1.0

Who Is the Fairest of Them All?

D

The first filial (F1) generation is the result ofa. cross-pollination among parents and the next generation.

b. crosses between individuals of the parental generation.

c. crosses between the offspring of a parental cross.

d. self-fertilization between parental stock.

Who Is the Fairest of Them All?

B

Who Is the Fairest of Them All?

Which of the following is the designation for Mendel’s original pure strains of plants?a. P c. F2

b. F1 d. F3

A

Who Is the Fairest of Them All?A genetic trait that appears in every generation of offspring for Mendel’s experiments is calleda. dominant. c. recessive.b. phenotypic. d. superior.

A

Who Is the Fairest of Them All?If an individual has two recessive alleles for the same trait, the individual is said to bea. homozygous for the trait.b. haploid for the trait.c. heterozygous for the trait. d. mutated.

A

Who Is the Fairest of Them All?How many different possible phenotypes can be produced by a pair of incomplete dominant alleles?a. 1 c. 3b. 2 d. 4

C

Who Is the Fairest of Them All?In humans, having freckles (F) is dominant to not having freckles (f). The inheritance of these traits can be studied using a Punnett square similar to the one shown below.

Refer to the illustration to the side. The genotype represented in box “1” in the Punnett square woulda. be homozygous for freckles.b. have an extra freckles chromosome.c. be heterozygous for freckles.d. have freckles chromosomes.

A

Who Is the Fairest of Them All?The difference between a monohybrid cross and a dihybrid cross is thata. monohybrid crosses involve traits for which only one allele

exists, while dihybrid traits involve two alleles.

b. monohybrid crosses involve self-pollination, while dihybrid crosses involve cross-pollination.

c. monohybrid crosses involve one characteristic or gene; dihybrid crosses involve two characteristic or genes.

d. dihybrid crosses require two Punnett squares; monohybrid crosses need only one.

C

Who Is the Fairest of Them All?Which of the following genotypes would you not expect to find among the offspring of a SsYy x ssyy test cross: a. ssyy d. ssYyb. SsYy e. SsYYc. Ssyy

E

Who Is the Fairest of Them All?The law of segregation states thata. alleles of a gene separate from each other during meiosis.b. different alleles of a gene can never be found in the same organism.c. each gene of an organism ends up in a different gamete.d. each gene is found on a different molecule of DNA.

A

Who Is the Fairest of Them All?The phenotype of an organisma. represents its genetic composition.b. reflects all the traits that are actually expressed.c. occurs only in dominant pure organisms.d. cannot be seen.

B

Who Is the Fairest of Them All?A reproductive process in which fertilization occurs within a single plant is ____________a. cross pollination c. self pollinationb. fertilization d. homo pollination

C

Who Is the Fairest of Them All?The transferring of pollen between different plants is called __________________a. cross pollinatin c. self pollinationb. fertilization d. homo pollination

A

Who Is the Fairest of Them All?When two members of the F1 generation are allowed to breed with each other or self pollinate, the offspring are referred to as the ____________________ generation.a. P generation c. F1 generationb. P2 generation d. F2 generation

F2

Who Is the Fairest of Them All?In Mendel’s experiments, a trait that disappeared in the F1 generation but reappeared in the F2 generation was always a ____________________.a. dominant c. homozygousb. recessive d. heterozygous

B

Who Is the Fairest of Them All?A phenomenon in which a heterozygous individual has a phenotype that is intermediate or blend between the phenotypes of its two homozygous parents is called ____________________.a. codominance c. incomplete dominanceb. complete dominance d. intermediate dominance

C

Who Is the Fairest of Them All?The objective or purpose of Mendel’s experiments were to study each characteristic trait in hopes of understanding ____________________________.

a. pea plants c. pea plant DNAb. genetic variation d. everything

B

Who Is the Fairest of Them All?A table used to determine and diagram the results of a genetic cross is called a ____________________.a. karyotype c. genetic chartb. punnett square d. matrix

B

Who Is the Fairest of Them All?____________________ allow for cross-pollination to occur. a. Fertilizers c. Breedersb. Pollinators d. Hybrids

B

Who Is the Fairest of Them All?The law of independent assortment states thata. alleles of a gene separate from each other during

meiosis randomly

b. different alleles of a gene can never be found in the same organism.

c. each gene of an organism ends up in a different gamete randomly.

d. each gene is found on a different molecule of DNA randomly.

A

Who Is the Fairest of Them All?

The likelihood that a specific event will occur is called _____________________.a. inheritance c. geneticsb. mathematics d. probability

D

Who Is the Fairest of Them All?In what phase does the law of segregation and the law of independent assortment apply?a. mitosis: metaphase e. meiosis: prophaseb. meiosis: metaphase f. mitosis: prophasec. mitosis: anaphase g. meiosis: telophase d. meiosis: anaphase h. mitosis: telophase

D

Rumpelstiltskin: Taking Straw and Spinning it into Gold

Spin Straw into Gold(For each pair of bold faced terms circle one of the terms)Pollination occurs when ______________ is produced in the anther / stigma (which is the female / male part) is transferred to the anther / stigma (which is the female / male part).

Pollen, anther, male, stigma, female

Spin Straw into Gold

List 5 facts about Gregor Mendel’s life and his experiments that influenced our knowledge of genetics.

Answers will vary depending on what you want to remember about Mendel

• Refer to notes for assistance

Spin Straw into GoldCarrion beetles lay their eggs in dead animals and then bury them in the ground until they hatch. Assume that the preference for fresh meat (F) is dominant to the preference for rotted meat and that the tendency to bury the meat shallow (S) is dominant to the tendency to bury the meat deep. Suppose a female carrion beetle homozygous dominant for both traits mates with a male homozygous recessive for both traits. What will be the genotypes and phenotypes of the F1 generation?

FfSs – Fresh Meat and Shallow bury

Spin Straw into GoldRumpelstiltskin meets a strong-willed fair maiden (Belle) who makes him see the error of his ways. They marry and decide to have lil stiltskins. Rumpelstiltskin has green body color and is heterozygous for spinning straw into gold. Belle is heterozygous for pale body color but has no ability to spin straw into gold. The couple knows that a child that spins straw into gold will be financially secure for the rest of his/her life. (in other words they will not need to live off Rumpel and Belle) Rumpelstiltskin and Belle want to know the odds that their child will have the ability to spin straw into gold.

There is a 50% chance that Rumpelstiltskin and Belle will have

a child that can spin straw into gold.