yr 10-genetics Flashcards
What does DNA stand for
Deoxyribose Nucleis acid
what is DNA and where is it found
It is the genetic code that controls cell growth and activities. It is found in the nucelus and mitochondria of a cell
what are nucleotides made of
made up of one Phosphate, One sugar and One base. Nucleotides are arranged in two long strands called a ‘Double Helix’
what are the four possible nitrogenous bases
(Adenine, Guatine, Cytosine and Thymine) although there is a specific way to pair them.
(AT) and (GT)
A and T have two hydrogen bonds
C and G have three hydrogen bonds
what is a chromosome and how many are in humans
a chromosome is a very long strand of DNA there are 46 in humans (23 pairs)
how are proteins formed?
3 letters in the genetic code make up an amino acid
They attach together to form different kinds of proteins
what is a mutation?
A mutation is a change to the genetic code, this will affect the formation of proteins because the amino acids will be altered.
what are sperm and egg cells called and how many chromosomes are in them
they are called gametes and they have only 23 chromosomes (haploid)
what are testes and ovaries calledd and how many chromosomes are in them
They are called germline, Testes or ovaries have 46 chromosomes-23 pairs (diploid)
female chrmosome
XX
male chromosome
XY
define allele
variation of a gene
homozygous
Alleles possessd for a particular gene are the same (yy)
heterozygous
Alleles possessed for a particular gene are different (Yy)
Genotype
The version of the gene (alleles) carried (yy, YY, Yy)
