Genetics: How does our genotype influence our phenotype?

The human genome consists of 46 chromosomes, specifically 44 autosomal chromosomes, similar in both males and females, and 2 gender specific sex chromosomes (X and Y). It has been known for many years, based on Mendel's pea experiments, that DNA recieved from both parents can be variably expressed to produce offspring with different characteristics, but how does this occur?

DNA is the chemical sequence that encodes the production of all bodily proteins, from enzymes in our stomach to keratin in our hair. Genes are specific sequences of DNA which determine certain features such as eye colour, with alleles being different forms of these genes. A child inherits alleles from both parents and so may inherit the allele for blue eyes from their mother and the allele for brown eyes from their father. Which allele is expressed depends on the dominance of the gene, meiosis and mutation. Mutations may occur either at the level of DNA e.g. substitutions or deletions of bases, or at  the chromosomal level, e.g. issues of assortment, structure or number of chromosomes. Therefore our phenotype is the combined result of which alleles we inherit and the form in which the DNA persists. 

Answered by Phoebe V. Biology tutor

2935 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

What is a myocardial infarction and how is it treated?


How are blood glucose levels controlled in the body?


How does blood flow through the heart and body?


What types of infectious agents are there?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy