Table of contents

1. Introduction to Biology2h 42m
2. Chemistry3h 37m
3. Water1h 26m
4. Biomolecules2h 23m
5. Cell Components2h 26m
6. The Membrane2h 31m
7. Energy and Metabolism2h 0m
8. Respiration2h 40m
9. Photosynthesis2h 49m
10. Cell Signaling59m
11. Cell Division2h 47m
12. Meiosis2h 0m
13. Mendelian Genetics4h 44m
14. DNA Synthesis2h 27m
15. Gene Expression3h 6m
16. Regulation of Expression3h 31m
17. Viruses37m
- Viruses
  37m
18. Biotechnology2h 58m
19. Genomics17m
- Genomes
  17m
20. Development1h 5m
21. Evolution3h 1m
22. Evolution of Populations3h 53m
23. Speciation1h 37m
24. History of Life on Earth2h 6m
25. Phylogeny2h 31m
26. Prokaryotes4h 59m
27. Protists1h 12m
28. Plants1h 22m
29. Fungi36m
- Fungi
  19m
- Fungi Reproduction
  17m
30. Overview of Animals34m
- Overview of Animals
  34m
31. Invertebrates1h 2m
32. Vertebrates50m
33. Plant Anatomy1h 3m
34. Vascular Plant Transport1h 2m
- Water Potential
  1h 2m
35. Soil37m
- Soil and Nutrients
  20m
- Nitrogen Fixation
  16m
36. Plant Reproduction47m
- Flowers
  33m
- Seeds
  14m
37. Plant Sensation and Response1h 9m
38. Animal Form and Function1h 19m
39. Digestive System1h 10m
- Digestion
  1h 3m
- Blood Sugar Homeostasis
  7m
40. Circulatory System1h 49m
41. Immune System1h 12m
42. Osmoregulation and Excretion50m
- Osmoregulation and Excretion
  50m
43. Endocrine System1h 4m
- Endocrine System
  1h 4m
44. Animal Reproduction1h 2m
- Animal Reproduction
  1h 2m
45. Nervous System1h 55m
- Neurons and Action Potentials
  1h 8m
- Central and Peripheral Nervous System
  46m
46. Sensory Systems46m
- Sensory System
  46m
47. Muscle Systems23m
- Musculoskeletal System
  23m
48. Ecology3h 11m
49. Animal Behavior28m
- Animal Behavior
  28m
50. Population Ecology3h 41m
51. Community Ecology2h 46m
52. Ecosystems2h 36m
53. Conservation Biology24m
- Conservation Biology
  24m

13. Mendelian Genetics

Incomplete Dominance vs. Codominance

General Biology

13. Mendelian Genetics

Incomplete Dominance vs. Codominance

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1:45 minutes

Problem 2

Textbook Question

A man with type A blood marries a woman with type B blood. Their child has type O blood. What are the genotypes of these three individuals? What genotypes, and in what frequencies, would you expect in future offspring from this marriage?

Verified step by step guidance

Step 1: Identify the blood types and their corresponding genotypes. Type A blood can be AA or AO, type B blood can be BB or BO, and type O blood is always OO.

Step 2: Determine the parents' genotypes based on the child's blood type. Since the child has type O blood (OO), each parent must have contributed an O allele. Therefore, the man's genotype must be AO and the woman's genotype must be BO.

Step 3: Use a Punnett square to predict the genotypes of future offspring. The Punnett square for this cross would look like this: | | A | O | |---|---|---| | B | AB | BO | | O | AO | OO |

Step 4: Determine the frequencies of the genotypes. According to the Punnett square, there is a 25% chance for each genotype (AB, BO, AO, OO) in future offspring.

Step 5: Translate the genotypes into blood types. The possible blood types for future offspring are A (AO), B (BO), AB (AB), and O (OO), each with a 25% chance.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Blood Type Genetics

Blood types are determined by the ABO gene, which has three alleles: A, B, and O. A and B are co-dominant, meaning that if both are present, both traits are expressed, while O is recessive. Therefore, individuals with type A blood can have genotypes AA or AO, and those with type B can have BB or BO. Type O blood results from the genotype OO.

Punnett Square

A Punnett square is a tool used in genetics to predict the genotypes of offspring from parental genotypes. By arranging the alleles of each parent along the axes of a grid, one can visualize the possible combinations of alleles in the offspring. This method helps in determining the probabilities of each genotype occurring in future generations.

Mendelian Inheritance

Mendelian inheritance refers to the patterns of inheritance first described by Gregor Mendel, which include the principles of segregation and independent assortment. These principles explain how alleles segregate during gamete formation and how traits are inherited independently of one another. Understanding these principles is crucial for predicting the genetic outcomes of offspring in a given cross.