Inheritance 7.3 Flashcards
What is the definition of genotype?
The genetic constitution of an organism, describing all the alleles the organism contains
What is the definition of allele?
A different version of a gene
What is the definition of a gene?
A base sequence of DNA on a chromosome which codes for the amino acid sequence of a polypeptide or functional RNA
What is a gamete?
A cell containing the haploid number of chromozomes
What is the phenotype?
The expression of the genetic constitution and its interaction with the environment
What is the definition of homologous chromosomes?
Chromosomes occur in pairs in diploid cells. They contain the same genes and gene loci, but may have different alleles
What is the definition of diploid cells?
A cell containing two sets of chromosomes in the nucleus
What is the definition of a chromosome?
Made of DNA and histone proteins, each has a different number of them and they contain all the genes for an organism
What is the definition of a gene locus?
The allele of each gene is found at a fixed position on each chromosome in a pair
What is a mutation?
A change in the DNA, which can change the genotype
What does a gene being expressed mean
Expression of a gene means how it is transcribed I to mRNA and then how mRNA is translated into a protein
Dominant allele
The allele that is always expressed in the phenotype when in the presence of another identical allele
Recessive allele
The allele that is only expressed in the phenotype in the presence of another identical allele
Monohybrid inheritance
The inheritance of a single gene on an autosome
What is co-dominance
Both alleles are expressed in the phenotype
What is an example of co-dominance
Sickle cell anaemia
What is sex-linked inheritance
Inheritance of a gene found on the X or y chromosome
What is dihybrid inheritance
Inheritance of 2 different genes on different chromosomes
What is Autosomal linked inheritance
Autosomal inheritance is the inheritance of 2 or more genes carried on the same autosome
What is epistasis
Epistasis arises when the allele of one gene affects or masks the expression of another gene
What is a gene pool
All the alleles in a population are know as the gene pool
What is the phenotype frequency
How often a phenotype appears in a population
This is easy to measure as we can see the phenotype
What is allele frequency
How often an Individual occurs within a gene pool
What is the equation for Hardy- Weinberg
Frequency of alleles
p + q = 1
Frequency of genotype
p2 + 2pq + q2 = 1
What are the assumptions of hardy Weinberg
Hardy Weinberg assumes that the frequencies of the alleles and genotypes will be the same in subsequent generations
-the population is large
-mating is random
-there is no immigration
-there are no mutations
-there is no selection
What are some uses of Hardy-Weinburg?
How common certain disease causing alleles are in a population
_________ the rate of evolution by seeing if the allele frequencies change over time
What is the definition of genome?
All the different alleles an organism contains
What is the definition of genome?
All the different alleles an organism contains
