Inheritance💘

Question 1

X linked inheritance

Answer 1

This is when there is a gene carried by the X chromosome
Usually revcessive
Men are more likely to be affected whereas women carriers because their other X chromosome can cancel it out

Question 2

What is non disjunction

Answer 2

When a pair of homologous chromosomes fail to separate during meiosis resulting in uneven chromosome numbers in eg Down syndrome is when there is an extra copy of chromosome 21

Question 3

Somatic mutations vs germ line

Answer 3

Somatic only affects individual whereas gremlins can be passed on as germ cells (sex cells) are also affected

Question 4

Genetic polymorphism

Answer 4

When a gene allele can have two or more variants

Variants can be classed as common or rare

Question 5

Types of genetic polymorphism

Answer 5

Short tandem repeats STR repeated DNA sequence motifs (micro satellites)
Single nucleotide variants SNV ,usually no effect 1snv per 1000
Restriction fragment length polymorphisms RFLP bacterial restriction enzymes used to cleave dna
STR AND SNV usually in non coding regions

Question 6

Genetic variation will remain constant if

Answer 6

No migration
No natural selection 
Random mating 
No mutation 
Infinite population size