ICSE Class 10 Biology
Question 9 of 11
Genetics — Some Basic Fundamentals — Question 3
Back to all questions(i) Difference between Monohybrid and Dihybrid cross:
| Monohybrid Cross | Dihybrid cross |
|---|---|
| Single feature is taken into consideration | Two features are taken into consideration. |
| Phenotypic ratio in second generation is 3:1 | Phenotypic ratio in second generation is 9:3:3:1 |
| Genotypic ratio is 1:2:1 | Genotypic ratio obtained is very complex |
(ii) Difference between Genotype and Phenotype:
| Genotype | Phenotype |
|---|---|
| Set of genes present in any organism is known as its genotype. | Characters expressed or physical appearance of characters is called phenotype. |
| Can be determined by genotyping method. | Can be determined by observation. |
| It is formed by expressed and unexpressed genes. | It consists of only expressed genes. |
(iii) Difference between Character and Trait:
| Character | Trait |
|---|---|
| Any inheritable feature of an organism is a character. | The alternative forms of a character are called traits. |
| For example, flower colour is a character. | For example, within the character of flower colour, specific traits will be red, blue, or white flower colour. |
(iv) Difference between Dominant and Recessive Allele:
| Dominant Allele | Recessive Allele |
|---|---|
| The gene that expresses itself phenotypically. | The gene that remains unexpressed in presence of dominant allele. |
| Expresses in homozygous as well as heterozygous condition. | Expresses only in homozygous condition. |
| Represented by capital letters. | Represented by small letters. |
(v) Difference between Autosomes and Sex chromosomes:
| Autosomes | Sex chromosomes |
|---|---|
| Autosomes are chromosomes that determine the general body features. | Sex chromosomes determine the sex of an organism. |
| Humans have 22 pairs of autosomes. | Humans have 1 pair sex chromosomes. |