Inheitance, Variation And Evolution Flashcards
DNA
genetic material in the nucleus of a cell. Has a double helix structure
A gene
A small section of DNA that codes for a particular sequence of amino acids to form a specific protein
A genome
The entire set of DNA in an organism
Human genome project
Aims to determine the DNA sequence of the entire human genome and record every gene in human beings
Female sex chromosomes
XX
Male sex chromosomes
XY
Gamete
Sex cells
Chromosome
Thread-like structures of DNA that carry genetic information in form of genes. Located in the nucleus
Alleles
Different versions of a particular gene
Dominant allele
An allele that is always expressed, even if only one copy is present
Recessive allele
An allele that is only expressed if 2 copies are present
Homozygous
When 2 alleles of a gene are the same
Heterozygous
When 2 alleles of a gene are different
Genotype
Combination of alleles that control each characteristic
Phenotype
Observable characteristics of an organism e.g. eye colour, hair colour, height, weight
Monohybrid inheritance
Characteristics that are controlled by a single gene which contains two alleles, one allele is inherited from the mother and the other from the father
Four bases of DNA structure
Adenine, thymine, cytosine, guanine
Complementary base pairing
Adenine + thymine, cytosine + guanine
In vitro fertilisation (IVF)
a process of fertilisation where an egg is combined with sperm in a test tube and then the embryos are inserted back into the mother’s uterus.
How does IVF reduce the chances of inherited diseases?
The cells from the embryo can be tested for a genetic disorder before being placed in the mother’s uterus. Therefore you would not implant the affected embryos.