Reproduction Flashcards
describe the structure of DNA ?
The DNA molecule consists of two strands that wind around one another to form a shape known as a double helix.
What is DNA ?`
DNA is the chemical that all of the genetic material in a cell is made up from
Where is DNA found ?
DNA is found in the nucleus of animal and plant cells
Its found in really long structures called chromosomes
What is a genome ?
A genome is the genetic material in an organism.
What is a gene ?
A small section of DNA found on a chromosome
Each gene codes for a particular sequence of amino acids
Amino acids join together to make protein
What is genotype ?
An organisms genetic information
What is phenotype ?
Observable physical traits
What is heterozygous ?
One dominant and one recessive allele
e.g. Bb
What is Homozygous ?
2 of the same allele
e.g. BB or bb
What is homozygous dominant ?
2 dominant alleles
e.g. BB
What is homozygous recessive ?
2 recessive alleles
e.g. bb
What is allele ?
An allele is a variant form of a gene
How many chromosomes are in each human body cell ?
23 chromosomes
What does 22 chromosome determine ?
They determine your characteristics
What does chromosome 23rd pair determine ?
If you are male or female
What chromosomes do males have ?
They have one X and Y chromosome
The Y chromosome causes male characteristics
What chromosomes do females have ?
They have 2 X chromosomes
The XX allows female characteristics to develop
What chromosome does sperm have and what does the egg have ?
Sperm has either X or Y chromosome
All egg cells have an X chromosome
What is cystic fibrosis ?
An inherited disorder of cell membrane
Its caused by a recessive allele
What is cystic fibrosis controlled by ?
It is controlled by a single gene which has 2 alleles
What is a carrier ?
Someone who has 1 cystic fibrosis allele and 1 normal allele which means they don’t have cystic fibrosis
How can a child get cystic fibrosis ?
Both parent must be carriers or have the disorder themselves
What is the inherited disorder polydactyly ?
People with polydactyly have extra fingers or toes
What is polydactyly caused by ?
It is caused by a dominant allele this means that a person with 1 polydactyly and 1 normal allele will have polydactyly
You can’t be a carrier of polydactyly
