Keystone Review Anchor 6

Welcome to Biology!

​Today: Biology Keystone Anchor 6: Genetics
Next Time: Biology Keystone Anchor 8: Ecology

Joke of the Day:

• Allele

• Anticodon

• Base Pairing

• Codon

• Codominance

• Clone

• DNA fingerprinting

• DNA Polymerase

• Fertilization

• Gametes

• Gene

• Gene Expression

Vocabulary:

• Gene Therapy

• Genetic Code

• Genetic Marker

• Genetics

• Genome

• Genotype

• Heterozygous

• Homozygous

• Hybrid

• Incomplete Dominance

• Independent Assortment

• Multiple Alleles

• messenger RNA (mRNA)

• Nondisjunction

• Nucleic Acid

• Nucleotides

• Polymerase Chain Reaction (PCR)

• Phenotype

• Plasmid

• Polygenic Trait

• Polypeptide

• Principle of Dominance

• Probability

• Recombinant DNA

• Replication

• Ribosomal RNA (rRNA)

• RNA

• RNA Polymerase

• Law of Segregation

• Sex Chromosome

• Sex-Linked Gene

• Trait

• Transcription

• Transfer RNA (tRNA)

• Transgenic

• Translation

Draw

Circle any words you're unfamiliar with.

Underline any that you are confident you know.

Multiple Choice

In Mendel's law of segregation, alleles sort _____ because the gene is located on a specific _____ .

• independently; chromosome

• in pairs; chromosome

• independently; gamete

• in groups; gamete

Multiple Choice

The law of independent assortment states that:

• The alleles of two genes sort into the gametes independently of the alleles of another two gene

• The alleles of one gene sort into the gametes independently of the alleles of another gene

• The gametes of one gene sort into the alleles independently of the gametes of another gene

• The genes of one organism sort into the gametes independently of the genes of another organism

Draw

Purple Flower = Dominant

White Flower = Recessive

Cross a homozygous purple flowered pea plant with a white flowered pea plant.

Circle the purple flowered offspring genotypes.

Multiple Choice

Suppose a trait is controlled by a gene that has one dominant allele (G) and one recessive allele (g).

Which of the following crosses would be expected to produce the greatest variety of genotypes among the offspring?

• GG × GG

• GG × gg

• Gg × Gg

• Gg × gg

Multiple Choice

Hawaiian happy face spiders from the island of Maui can have different markings, as shown below. A single gene determines the markings on the spiders.

A plain spider is crossed with a patterned spider. The patterned spider is homozygous. The pattern allele is dominant to the plain allele.

What percentage of the offspring from this cross are expected to be patterned instead of plain?

• 0 percent

• 25 percent

• 50 percent

• 100 percent

Multiple Choice

The table below gives information about the feather color phenotypes of parents and offspring for several different crosses of turkeys. Each parent turkey is true-breeding (homozygous) for its feather color.

Based on the results of the crosses, which of the following statements best describes how alleles for feather color interact?

• The bronze allele is recessive to the black allele and the red allele.

• The red allele is dominant to the black allele and the bronze allele.

• The black allele is dominant to the bronze allele and recessive to the red allele.

• The bronze allele is dominant to the red allele and recessive to the black allele.

Multiple Choice

Fruit flies have hair-like bristles on the back side of their bodies. The bristles can be long or short. Flies with short bristles have two recessive alleles (ss) for the trait. A fruit fly that is heterozygous for the bristle trait is crossed with a fruit fly that has short bristles. The cross produces 220 offspring.

How many of the offspring are expected to have short bristles?

• 0

• 55

• 110

• 220

Draw

In rabbits, fur color exhibits incomplete dominance. 

The allele for black fur (B) is incompletely dominant to the allele for white fur (W). Gray rabbits are BW.

Cross two gray rabbits.

Multiple Choice

A newly discovered gene has two alleles, A and a. Scientists hypothesize that the alleles show incomplete dominance. Which statement can be used as evidence for incomplete dominance?

• Individuals with genotype aa survive only a few days after birth.

• Analysis of the DNA shows that only males have genotype AA.

• Crosses between two individuals with genotype Aa result in the three different phenotypes.

• Individuals with genotype AA and individuals with genotype Aa both have the same phenotype.

Multiple Choice

Leaves from two white clover plants, each with a different pattern, are shown below.

The leaf patterns are genetically determined by alleles of a single gene. Plant 1 is homozygous for the chevron allele. Plant 2 is homozygous for the oval allele. The chevron and oval alleles are codominant.

If Plant 1 and Plant 2 are crossed, the codominance of the alleles will most likely result in which of the following leaf patterns on the offspring plants?

Multiple Choice

The table below shows the genotypes that result in four different blood types in humans.

Based on the information in the table, which of the following describes this pattern of inheritance?

• The IA and IB alleles show sex linkage.

• The IA allele is recessive to the IB allele.

• The IA allele is dominant to the IB allele.

• The IA and IB alleles show codominance.

Multiple Choice

Hemophilia is an X-linked recessive condition in which blood does not clot properly. Queen Victoria of England had one allele for hemophilia. Which of the following statements describes the most likely pattern for the occurrence of hemophilia in Queen Victoria’s descendants?

• All of Queen Victoria’s children had hemophilia.

• All of Queen Victoria’s children were carriers for hemophilia.

• Female descendants of Queen Victoria could not pass on the gene for hemophilia.

• More male descendants than female descendants of Queen Victoria had hemophilia.

Multiple Choice

Human HLA genes have as many as 100 different alleles per gene. The alleles code for proteins that are involved in accepting or rejecting an organ following an organ transplant. Which statement correctly explains why this multiple allele inheritance pattern makes it difficult to match an organ donor with an organ recipient?

• Each organ in a person’s body expresses a different allele.

• The donor must have dominant alleles for the organ to be accepted.

• The alleles cannot mutate in the recipient’s body after the transplant.

• Most people do not have the same combination of alleles for the genes.

Multiple Choice

Larry is treated for type 1 met-H with vitamin C, and his skin no longer looks blue. How does this affect the likelihood of Larry passing on the allele for type 1 met-H to his offspring?

• Larry will now pass on a normal allele to his offspring.

• Larry will still pass on an allele for type 1 met-H to his offspring.

• Larry will only pass on an allele for type 1 met-H if his offspring is male.

• Larry will have less of a chance of passing on an allele for type 1 met-H to his offspring.

Poll

How confident do you feel about this topic for the Keystones?

• Very confident.

• Confident.

• Not confident.

• Scared.