Genetics, Populations, Evolution And Ecosystems Flashcards
Define genotype
An organisms genetic composition
Define phenotype
An organisms characteristics, which occurs as a result of both its genotype and the impact of the environment
What is an allele?
Alternative forms of a particular gene with different base sequences and therefore different codes
What are the four types of alleles?
Dominant
Recessive
Co-dominant
Multiple alleles
What is the difference between diploid and haploid cells?
Haploid cells contain only one set of chromosomes (half set -23) and diploid cells chromosomes occur in pairs (full set -46)
What are heterozygous cells?
Organisms in which paired alleles are different
E.G- Bb
What are homozygous cells?
Organisms in which paired alleles are the same.
E.G- BB or bb
Define monohybrid inheritance
Inheritance of a single pair of alleles- only one from each gamete (due to meiosis)
Define dihybrid inheritance
Inheritance of two different characteristics simultaneously
What is an autosome?
Chromosomes numbered (1-22) which are known as body cells not sex cells
State the difference between sex-linkage and autosomal linkage
Sex linkage occurs when there is a gene on the X chromosome, not present on the Y chromosome.
Whereas autosomal linkage occurs if two or more genes are located on the same autosome(non-sex chromosomes)
What is a species?
A group of organisms that can successfully interbreed
Define population
Members of the same species living in one habitat
Define gene pool
Complete range of alleles in a population
Define allele frequency
Relative frequency of a particular allele in a population
What is the hardy-Weinberg principle?
Explain the hardy-Weinberg equation for calculating allele frequency
Explain the hardy-weinberg equation to calculating genotype frequency
What are the conditions under which the Hardy- Weinberg principle equation applies?
What two factors affect variation?