Becky Corrigan

Numerade Educator
Teacher

Biography

I have been a teacher for 20+ years and I love getting to explore biology, AP biology and physics with my students! I am passionate about investigating the world around me, which is why I try to embark on outdoor adventures every opportunity I get. My goal in teaching is to help my students connect with their world through science, to ask questions and to engage in lifelong learning.

Education

Becky has not yet added their education credentials.

Educator Statistics

Numerade tutor for 4 years
5 Students Helped

Topics Covered

Mendelian Genetics: Understanding Inheritance Patterns
The Central Dogma: Understanding Gene Expression

Becky's Textbook Answer Videos

1

Becky's Quick Ask Videos

0:00
Biology

In a Mendelian dihybrid cross, two true-breeding plants
differing in seed color and seed shape are crossed. Yellow seeds
(Y) are dominant over green seeds (y) and round seeds (R) are
dominant over wrinkled (r).
What ratio of plants in the F2 generation would be expected
to produce yellow, wrinkled seeds?
9/16
1/4
1/16
3/4
3/16
In a Mendelian dihybrid cross, two true-breeding plants
differing in seed color and seed shape are crossed. Yellow seeds
(Y) are dominant over green seeds (y) and round seeds (R) are
dominant over wrinkled (r).
What ratio of plants in the F2 generation would be expected to
produce yellow, round seeds?
A. 3/4 B. 1/4 C. 9/16 D. 1/16 E. 3/16

Becky Corrigan
0:00
Biology

For the same cross: BbTt
bbTt
Using the Probability Method illustrated in lecture, break the complex two-gene cross into two simple single-gene crosses (note that the Probability Method can be used if it is known that the alleles of the different genes assort independently) (AP)
Bb x bb
Tt x Tt
Show the expected genotypic and phenotypic ratios for each of the simple single-gene crosses. (Make the simple Punnett Squares to get the ratios)
Using this information, show the calculations for determining the expected number of genotypes and the expected number of phenotypes among the offspring of the BbTt x bbTt cross. (Part of the answer is provided)
Expected # of Two-Trait Genotypes
(# of B genotypes) x (# of T genotypes) = genotypes
You can calculate the Expected # of phenotypes:
What is the expected frequency of BbTt offspring from the cross? (Show the calculation using the Product Rule)
What is the expected frequency of white coat, long tail offspring? Show the calculation using the Product Rule.
Set up a Branching Diagram for determining the Full Expected Genotypic Ratio among offspring of the cross. Include the calculation of the frequency of two of the genotypes for now (complete the calculations if there is time). If there is time, do the same for the Expected Phenotypic Ratio.

Becky Corrigan
0:00
Biology

Trait 2 Dog " Tail Length: Tail length in dogs can be long, short, or medium. The allele for long tails (T) is incompletely dominant to the allele for short tails (Ty). Write the phenotypes of the following genotypes: TLT; phenotype shows its dominance for long tail. TLTs: dominant for long or short tail. TsTs: dominant for short tail.

Create a Punnett square for a female dog with a short tail that mates with a male dog with a medium tail:
Mom Genotype; Dad Genotype

Becky Corrigan
07:06
Biology

A stray black cat in Lakewood, California, was found to have a unique dominant allele located on an autosome. The allele codes for a protein which causes curled ears in cats that have it. Now let's say that you have a female cat which is heterozygous for the allele and breed it with a male cat with normal ears. What is the genotype of your female, assuming the C allele is the dominant curly one, and the c allele is recessive for normal ears? What is the genotype of the male? Does either of these cats have the curly ear phenotype? If so, which one? If you breed them and they have 12 kittens, how many will likely have curly ears? Does the kitten's sex make a difference in what its ear phenotype is? Show the Punnett square.

Becky Corrigan
0:00
Biology

Activity 3: DNA Replication
Fig. 1 is a ladder model of a DNA double helix. From left to right, the base sequence of the top strand is ATGGCTTGAGAA. Fill in the bases in the top strand: Fill in the bases on the complementary bottom strand: Mark off the triplets in the bottom strand: How many are there?
5'
3

Becky Corrigan
1