CHAPTER 4 GENETIC INHERITANCE

WELCOME TO BIOLOGY LECTURE WEEK 6

Poll

How confident do you feel about solving dihybrid crosses?

• Very Confident: I can easily solve dihybrid crosses and predict genotypic and phenotypic ratios without assistance.

• Confident: I understand the concepts and can solve most problems, but occasionally need help.

• Somewhat Confident: I understand the basics but often require assistance to complete problems.

• Not Confident: I struggle with setting up and solving dihybrid crosses and need more practice.

Poll

How well do you understand the concept of linked genes and their effect on inheritance patterns?

• Very Well: I can explain linked genes and predict how they affect genetic ratios with confidence.

• Well: I have a good understanding but sometimes confuse certain aspects.

• C. Somewhat Well: I know the basic idea but have difficulty applying it to problems.

• Not Well: I find linked genes confusing and need more detailed explanations.

Poll

How comfortable are you with calculating genetic distances and creating genetic maps?

• Very Comfortable: I can easily calculate recombination frequencies and map units to create genetic maps.

• Comfortable: I understand the process but occasionally need clarification on certain steps.

• Somewhat Comfortable: I grasp the concept but struggle with calculations and need more practice.

• Not Comfortable: I find genetic mapping challenging and need more guidance.

IT IS OKAY!!!!

I GOT UR BACK

Multiple Choice

What is the expected phenotypic ratio in the F2 generation of a monohybrid cross involving two heterozygous individuals (e.g., Aa x Aa)?

• 1:2:1

• 3:1

• 9:3:3:1

• 1:1:1:1

Multiple Choice

In a genetic diagram, what does the symbol "Aa" represent?

• A homozygous dominant genotype

• A homozygous recessive genotype

• A heterozygous genotype

• A phenotype

Multiple Choice

What is the expected genotypic ratio in the F2 generation of a monohybrid cross between two heterozygous individuals (e.g., Aa x Aa)?

• 3:1

• 1:2:1

• 1:1

• 9:3:3:1

Multiple Choice

Which of Mendel's laws explains the inheritance pattern of two different traits in a dihybrid cross?

• Law of Segregation

• Law of Independent Assortment

• Law of Dominance

• Law of Linkage

Multiple Choice

In a genetic cross between two heterozygous individuals (AaBb x AaBb), what is the expected phenotypic ratio in the offspring?

• 3:1

• 1:1:1:1

• 9:3:3:1

• 1:2:1

Multiple Choice

What is the purpose of a Punnett square in a dihybrid cross?

• To predict the genotype of parents

• To determine the number of chromosomes

• To visualize the probability of genotypes and phenotypes in offspring

• To measure the genetic distance between genes

Multiple Choice

In a genetic cross between two heterozygous pea plants (RrYy x RrYy), where R (round seed) is dominant over r (wrinkled seed), and Y (yellow seed) is dominant over y (green seed), what is the expected phenotypic ratio in the offspring?

• 3 round yellow : 1 wrinkled green

• 1 round yellow : 2 wrinkled yellow : 1 round green

• 9 round yellow : 3 round green : 3 wrinkled yellow : 1 wrinkled green

• 1 round wrinkled : 1 green wrinkled

Multiple Choice

When considering linked genes, how might their inheritance pattern differ from the independent assortment seen in Mendel's dihybrid crosses?

• Linked genes result in a 9:3:3:1 ratio like independently assorting genes.

• Linked genes tend to be inherited together, causing deviations from the 9:3:3:1 ratio

• Linked genes show recombination more frequently than independent genes.

• Linked genes only produce parental phenotypes with no recombination.

Multiple Choice

How does crossing over affect linked genes during meiosis?

• It strengthens the linkage between the genes..

• It breaks the linkage between genes, resulting in recombinant phenotypes.

• It causes all offspring to display only parental phenotypes..

• It has no effect on linked genes.

Multiple Choice

Which of the following genetic diagrams correctly represents the cross between an individual with genotype AaBb and an individual with genotype aabb, where the genes are linked?

• The phenotypic ratio is 9:3:3:1

• The phenotypic ratio is 1:1:1:1

• The phenotypic ratio is 3:1

• The phenotypic ratio is dependent on the crossover frequency between genes

Multiple Choice

What does a genetic map unit (m.u.) or centimorgan (cM) represent in the context of genetic mapping?

• The physical length of a chromosome.

• A unit of measurement representing the distance between genes based on recombination frequency.

• The number of alleles present in a gene pool.

• The total number of chromosomes in a cell.

Multiple Choice

If two genes have a recombination frequency of 10%, what is their approximate distance on a genetic map?

• 1 map unit

• 10 map units

• 100 map units

• 0 map units