B5-Genes and Inheritance Flashcards
What are alleles?
Different forms of the same gene
What is a dominant allele?
The allele which if it is present determines the phenotype
What is a recessive allele?
An allele which must be a homozygous pair to determine the phenotype
What is the phenotype?
The appearance of a particular characteristic which are expressed by the combination of alleles
What is the genotype?
The alleles present on the chromosomes for a characteristic
What is a ‘homozygous’ pair?
When the two alleles are present in chromosomes are the same
E.g. ‘AA’ or ‘aa’
What is a ‘heterozygous’ pair?
When the two alleles are present in chromosomes are the different
E.g. ‘Aa’
(Always write the dominant before the recessive ‘aA’ would be wrong)
What are sections of Dna that code for a protein?
DNA
Height is a ‘…….’ factor?
Environmental
Eye colour is a ‘…….’ factor?
Genetic
Skin colour is a ‘…….’ factor?
Environmental
Blood type is a ‘…….’ factor?
Genetic
Hair colour is a ‘…….’ factor?
Genetic
Shoe size is a ‘…….’ factor?
Environmental
What is discontinuous variation?
Characteristics that fall into distinct groups commonly categorised as discrete data due to having finite options
E.g. Eye colur can only be a certain few colours and there is only male and female for gender
What is continuous variation?
Characteristics that can take any value within a range that are commonly categorised at continuous data due to having many options
E.g. Height and weight will never be exact as your weight could be 67.56783567 or maybe 67.56783568 and the numbers could go on to make it more exact which makes it continuous
How is discontinuous data shown on a graph?
Normally presented in a bell-shaped curve
How is continuous data shown on a graph?
Normally presented a bar chart
What is asexual reproduction?
Reproduction where a single organism produces a gentically identical offspring
What are the benefits of asexual reproduction?
Good traits are guaranteed to be passed onto offspring
What are the disadvantages of asexual reproduction?
Since there are all gentically a same a virus that would prove fatal to one organism would prove deadly for all of them and wipe them out
Does asexual reproduction use mitosis or meiosis?
Mitosis as it still needs to create cells with 46 chromosomes
What is sexual reproduction?
Sexual reproduction is where haploid cells from two different organisms are fused to form a zygote (diploid cell) which is genetically different to the parent. This causes variation for genetically different gametes which cause further variation.
What is a haploid cell?
A cell containing one set of chromosomes
What is a diploid cell?
A cell containing two sets of chromosomes
What is mitosis?
Process of cell duplication where a cell divides once to end up with two diploid cells
What is meiosis?
Process where a single cell divides twice to produce four haploid cells
What is mitosis used for?
Growth and repair of tissues
What is meiosis used for?
Production of gametes
Where does mitosis take place?
Every cell
Where does meiosis take place?
Occurs in gametes
What are two ways to determine the phenotype of an offspring?
Punnett Squares and Genetic Crosses
