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

Punnett Squares

General Biology

13. Mendelian Genetics

Punnett Squares

Previous problemNext problem

3:54 minutes

Problem 11

Textbook Question

In tigers, a recessive allele of a particular gene causes both an absence of fur pigmentation (a white tiger) and a cross-eyed condition. If two phenotypically normal tigers that are heterozygous at this locus are mated, what percentage of their offspring will be cross-eyed? What percentage of cross-eyed tigers will be white?

Verified step by step guidance

Step 1: Understand the problem. In this case, we are dealing with a recessive allele that causes two traits: absence of fur pigmentation (white tigers) and a cross-eyed condition. The tigers in question are heterozygous, meaning they carry one dominant and one recessive allele. The dominant allele is for normal pigmentation and eye condition, while the recessive allele is for white fur and cross-eyed condition.

Step 2: Use the Punnett square to predict the genotypes of the offspring. Since both parents are heterozygous (let's denote the dominant allele as 'A' and the recessive allele as 'a'), the Punnett square will look like this: AA, Aa, aA, aa. This means that 25% of the offspring will be homozygous dominant (AA), 50% will be heterozygous (Aa or aA), and 25% will be homozygous recessive (aa).

Step 3: Determine the percentage of offspring that will be cross-eyed. Since the cross-eyed condition is caused by the recessive allele, only the homozygous recessive offspring (aa) will be cross-eyed. According to the Punnett square, this is 25% of the offspring.

Step 4: Determine the percentage of cross-eyed tigers that will be white. Since the white fur and cross-eyed condition are caused by the same recessive allele, all cross-eyed tigers will also be white. Therefore, 100% of cross-eyed tigers will be white.

Step 5: Summarize the results. 25% of the offspring will be cross-eyed and white, and 100% of cross-eyed tigers will be white.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

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

Mendelian Genetics

Mendelian genetics is the study of how traits are inherited through generations based on the principles established by Gregor Mendel. It involves understanding dominant and recessive alleles, where a recessive allele only expresses its trait when two copies are present. In this case, the recessive allele causes both the white fur and cross-eyed condition in tigers.

Punnett Square

A Punnett square is a diagram used to predict the genotypes of offspring from a genetic cross. By organizing the alleles of the parents, it allows for the visualization of possible combinations and the probabilities of each genotype. In this scenario, it will help determine the percentage of offspring that will be cross-eyed when two heterozygous tigers are mated.

Phenotype and Genotype

Phenotype refers to the observable traits of an organism, while genotype refers to the genetic makeup that determines those traits. In this question, the phenotypically normal tigers have a heterozygous genotype, meaning they carry one dominant and one recessive allele. Understanding the relationship between genotype and phenotype is crucial for predicting the traits of the offspring.

Watch next

Master Punnett Squares with a bite sized video explanation from Jason

Start learning

Related Videos

Related Practice

Textbook Question

In garden peas, yellow seeds (Y) are dominant to green seeds (y), and inflated pods (I) are dominant to constricted pods (i). Suppose you have crossed YYII parents with yyii parents. Draw the F2 Punnett square. Based on this Punnett square, predict the expected phenotype(s) in the F2 generation and the expected frequency of each phenotype.

1219

views

Textbook Question

In garden peas, yellow seeds (Y) are dominant to green seeds (y), and inflated pods (I) are dominant to constricted pods (i). Suppose you have crossed YYII parents with yyii parents. Draw the F1 Punnett square and predict the expected F1 phenotype(s).

In garden peas, yellow seeds (Y) are dominant to green seeds (y), and inflated pods (I) are dominant to constricted pods (i). Suppose you have crossed YYII parents with yyii parents. Draw the F1 Punnett square and predict the expected F1 phenotype(s).

840

views

Multiple Choice

In a monohybrid cross using a Punnett square, what is the expected genotypic ratio of the offspring when both parents are heterozygous for a trait?

447

views

Multiple Choice

In a dihybrid cross involving two heterozygous parents (AaBb x AaBb), what phenotypes would you predict in the F2 generation?

294

views

Multiple Choice

In a genetic cross using a Punnett square, which fraction represents 25% of the offspring?