Table of contents

1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

2. Mendel's Laws of Inheritance

Dihybrid Cross

Genetics

2. Mendel's Laws of Inheritance

Dihybrid Cross

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Multiple Choice

In a dihybrid cross between two Bikini Bottom creatures that are both heterozygous for square pants (S) and blue body color (B), what is the expected phenotypic ratio among their offspring if square pants (S) and blue body color (B) are both dominant traits?

3:1

2:1:1

1:1:1:1

9:3:3:1

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Verified step by step guidance

Identify the genotypes of the parents. Since both parents are heterozygous for square pants (S) and blue body color (B), their genotypes are SsBb.

Determine the possible gametes each parent can produce. Each parent can produce four types of gametes: SB, Sb, sB, and sb, due to independent assortment.

Set up a Punnett square with the gametes from one parent on the top and the gametes from the other parent on the side, creating a 4x4 grid to represent all possible combinations.

Fill in the Punnett square by combining the alleles from the corresponding gametes to find the genotypes of the offspring.

Classify the offspring genotypes into phenotypes based on dominance: any genotype with at least one dominant allele for square pants (S) will show square pants, and any genotype with at least one dominant allele for blue body color (B) will show blue color. Count the number of offspring in each phenotypic category to determine the phenotypic ratio.