Heredity Flashcards
What is monohybrid inheritance?
Monohybrid inheritance is an inheritance involving only one pair of contrasting traits.
What is a chromosome?
A chromosome is a rod-like structure visible in the nucleus during cell division. It is made up of the molecule deoxyribonucleic acid(DNA)
What is a gene?
A gene is a unit of inheritance, born on a particular position of a chromosome. It is a small segment of DNA in a chromosome that controls a particular characteristic or protein in an organism.
What are alleles?
Alleles are different forms of the same gene. They occupy the same relative positions on a pair of homologous chromosomes.
What is a phenotype?
Phenotype refers to the expressed traits in an organism, for example the outward appearance of an organism.
What is a genotype?
A genotype is the genetic-makeup of an organism, that is, the combination of genes in an organism.
What is codominance?
Codominance results when the two alleles controlling a trait both express themselves in the organism.
How is a sex of a person determined?
XX chromosome in the 23rd pair results in a female.
XY chromosome in the 23rd pair results in a male.
What are multiple alleles?
Multiple alleles is a term used for a gene that exists in more than 2 alleles.
What are variations?
Variations are differences in traits between individuals of the same species.
What is discontinous variation?
Discontinuous variation are traits that are easily distinguishable and are not affected by environmental conditions.
Examples: Ability to roll tongue, ABO blood group, single or double eyelid.
What is continous variation?
Continuous variation is brought by the combined or additive effect of many genes and they are affected by environmental conditions.
Examples: Height, skin colour, weight and intelligence.
What is mutation?
Mutation is the sudden random change in the structure of a gene or in the chromosome number.
