B1.2.1 - DNA Flashcards
Where is the DNA found in Prokaryotic and Eukaryotic cells?
In the nucleus
What is a chromosome?
A long coil of DNA molecules
How many chromosomes do most humans have?
46 - in pairs of 23 in each cell
How many chromosomes do chickens have?
Chickens have 78 chromosomes
How do you get these chromosomes?
You inherit half from your mother and half from your father
What are the only organisms that share identical DNA?
Identical twins and clones
What are genes?
Genes are short sections of DNA that code for a characteristic. The code that a gene contains causes specific proteins to be made, which determine the function of the cell
Name an example of a protein and what cell it is in.
The protein haemoglobin is for red blood cells. This binds to oxygen allowing red blood cells to transport oxygen around the body.
What is the structure of DNA?
DNA is made up of two strands. These strands are joined together by bases. The strands are then twisted together. This forms a shape known as a double helix.
Is DNA a polymer?
Yes, as DNA is made up of many monomers called nucleotides, which are joined together
What are Nucleotides made up of?
Each nucleotide is made of deoxyribose sugar, a phosphate group and a base. The two strands of DNA are held together by bonds between the bases.
What are the four bases that can be found in nucleotides?
The four bases are Adenine, Thymine, Cytosine and Guanine.
How do bases bond?
To hold the strands of DNA together, a base from one strand bonds a base on the other strand. This forms a base pair. The base pairs always bond together in the same formation - this is complementary base pairing : Adenine always bonds with Thymine and Cytosine always bonds with Guanine
Which chromosome pair determines your gender?
The 23rd, XX meaning female and XY meaning male
What are the two entries in your chromosomes which determine your features?
X and Y
