2.7a+b Flashcards
What is meiosis
Produces gametes in testes/ovaries, cells chromosome duplicate, cell undergoes 2 divisions to produce 4 cells with 23 the number of chromosomes of other body cells.
Ensures variation of offspring
What does dominant mean
Only needs 1 allele present to show characteristic
What does recessive mean
Needs 2 alleles to show characteristic
Shape of DNA that ,are up a chromosome
Double helix structure
Gene
Codes of characteristics
Allele
A version of a gene
Why is fertilisation important
Shows variation of offspring, through 2 parents both passing on genetic info bringing diff combinations of genes/alleles
Higher chance of survival against pathogen
What are stem cells
Cells that have not yet specialised by the process of differentiation
Main animal sources of stem cells
Embryonic (IVF infused embryos)
Umbilical cord
Adult stem cells (bone marrow)
Homozygous
2 alleles with the same pair of chromosomes
Heterozygous
2 diff alleles in a pair of chromosomes
Genotype
The type of gene
Phenotype
The characteristic
Embryo screening?
When a cell is removed from an embryo and check allele for genetic disorder
Who was Mendel
A monk who grew peas to show genetic variation
