Biology 6.1.6 Flashcards
What are ‘Gametes’?
Gametes are Sex Cells.
What are ‘Chromosomes’?
Chromosomes are Thread-Like Structures of DNA, Carrying Genetic Information in the Form of Genes. They are Located in the Nucleus of Cells.
What are ‘Genes’?
Genes are Short Lengths of DNA, Found on Chromosomes. They Code for Specific Proteins.
What are ‘Alleles’?
Alleles are Different Versions of a Particular Gene. EG Blue Eyes & Green Eyes are Alleles of the Eye Colour Gene.
What is a ‘Dominant Allele’?
A Dominant Allele is Always Expressed, even if only 1 Copy is Present.
What is a ‘Recessive Allele’?
A Recessive Allele is Only Expressed if 2 Copies are Present.
What is a ‘Homozygous’?
If the 2 Alleles of a Gene are the Same, we Describe the Individual as being Homozygous. (Homo = Same).
What is a ‘Genotype’?
The Combination of Alleles that Control Each Characteristic is Called the Genotype.
What is a ‘Phenotype’?
The Observable Characteristics of an Organism. EG Hair Colour.
Some Characteristics are Controlled by a Single Gene. The Inheritance of these Single Genes is Called…
Monohybrid Inheritance.
What is ‘Monohybrid Inheritance’?
The Inheritance of Single Genes that Control a Certain Characteristic.
As we have 2 Copies of Each Chromosome, we have 2 Copies of Each Gene, & therefore 2 ___ for Each Gene.
Alleles.
1 of the Alleles is Inherited from the ___, & the other from the ___.
Mother, Father.
Alleles do not have to ‘say’ the same thing. EG: an Individual has 2 Copies of the Gene for Eye Colour, but 1 ___ could be for Brown Eyes, & 1 ___ could be for Blue Eyes.
Allele, Allele.
The Combination of Alleles that Control Each Characteristic is Called the…
Genotype.
Alleles can be ___ or ___.
Dominant, Recessive.
What Must happen in Order for a Dominant Allele Characteristic to Show Up in the Phenotype?
A Dominant Allele Only Needs to be Inherited from 1 Parent in Order for the Characteristic to Show Up in the Phenotype.
What Must happen in Order for a Recessive Allele Characteristic to Show Up in the Phenotype?
A Recessive Allele Needs to be Inherited from Both Parents in Order for the Characteristic to Show Up in the Phenotype. In Other Words, in Order for a Recessive Allele to Appear in the Phenotype, there Must be no Dominant Alleles Present.
What will Happen if there is Only 1 Recessive Allele?
If there is Only 1 Recessive Allele, it will Remain Hidden, & the Dominant Characteristic will Show in the Phenotype.
If the 2 Alleles of a Gene are the Same, we Describe the Individual as Being…
Homozygous.
An Individual could be Homozygous ___, or Homozygous ___. What do both mean? (2)
-Homozygous Dominant: Having 2 Copies of the Dominant Allele.
-Homozygous Recessive: Having 2 Copies of the Recessive Allele.
If the 2 Alleles of a Gene are Different, we Describe the Individual as Being…
Heterozygous .
Characteristics that are Controlled by More than One Gene are Described as Being…
Polygenic.
The Inheritance of Polygenic Characteristics is Called…
Polygenic Inheritance.
What Diagram can be Used to Predict Possible Combinations of Alleles?
Punnett Square.
What does a ‘Punnett Square Diagram’ Show?
A Punnett Square Diagram Shows the Possible Combinations of Alleles that Could be Produced in the Offspring.
What will be the Genotype for ‘rR’?
Heterozygous Dominant.
What will be the Genotype for ‘RR’?
Homozygous Dominant.
What will be the Genotype for ‘rr’?
Homozygous Recessive.
