Inheritance Flashcards
What is mono hybrid inheritance?
Inheritance of a single characteristic controlled by one gene (each parent having two alleles for that gene)
What is a gene
Length of DNA which codes for one polypeptide
What is an allele
One version of a particular gene
What is a locus
Location of a gene on a chromosome
What is a genotype
The allele possessed by an organism
What is a phenotype
Characteristics of an organism often resulting from an interaction between its alleles and the environment.
What is meant by dominant?
An alleles affect on the phenotype of a heterozygote is identical to its effect in a homozygote, when present it is always expressed.
What is meant by recessive?
An allele which is only expressed were no dominant allele is present.
What is meant by codominant?
When both alleles have an effect on the phenotype of a heterozygous organism
What is heterozygous
Having two different alleles of a gene
What is homozygous
Having two identical alleles of a gene
What does F1 stand for?
First generation (first filial generation)
What does F2 stand for?
Second generation (second filial generation)
What is sex linkage
The inheritance of a gene only present on the X chromosome no allele present on the Y
What is genetics
Study of mechanisms by which an organism inherit characteristics from its parent.
What is Mendels first law?
The characteristics of an organism are determined by alleles which occur only in pairs. Only one of a pair of alleles can be present on a single gamete.
What are the Mendel first law rules?
- Both parents donate one copy of a gene to each offspring.
- A characteristic appearing in the phenotype must have at least one appropriate allele in the genotype.
- A recessive characteristic must be homozygous in order to express the phenotype.
- If two parents show a given characteristic which is not shown in the offspring the parents are heterozygous and the offspring is a homozygous recessive.
How is a test cross carried out?
Using a homozygous recessive.
What happens if the unknown is homozygous?
Oh offspring will express the dominant phenotype
If the unknown is heterozygous what happens?
Half of the offspring will show the recessive phenotypes.
What are the steps when carrying out a punnet square?
P.phenotypes p.genotypes gametes F1 genotype F1 phenotype.
What is pure breeding?
It refers to a variety bred for several generations will itself so that all individuals are homozygous. All offspring have the same Geno/phenotype as their parents.
What are multiple alleles?
When one when more than one allele can code for one particular gene.
What chromosome is no alleles found?
y