Genetics Flashcards
Where is genetic info stored?
cell nucleus
Where is DNA found?
in chromosomes within cell nucleus
What is DNA made up of?
base pairs: adenine, thymine, guanine, cytosine
Nucleotides
What is a genotype?
specific version of gene
What is a phenotype?
observable characteristics from genotype
What does diploid mean?
contain PAIR of chromosomes
How many chromosomes do we have?
22 pairs + 1 sex chromosome= 46 in total
What is the female chromosome?
46XX
What is the male chromosome?
46XY
What is a gamete?
sex cell
Each chromosome has a different look and is numbered according to size– true/false?
true
What is a chromosome made up of?
centromere (middle bit) short (p) and long (q) arms
What are the two types of cell division?
mitosis and meiosis
When does downsyndrome occur?
during meiosis cell division
How is downsyndrome caused?
uneven cell division- 1 gamete has too much info. Gamete then joins with normal gamete and have extra chromosome in chromosome 21.
Downsyndrome features include…
hypotonia (floppy), protruding tongue, cardiac abnormalities
klinefelters syndrome is only in males- true/false?
true
Features of klinefelters syndrome include…
hypogonadism (small genitals), infertility, tall stature
turners syndrome is only in males- true/false?
false
What is turner’s syndrome?
In girls, only 1 X no extra X or Y chromosome
2 chromosomes come from 1 parent and none from the other in prada willi- true or false?
true
What is imprinting?
genetic expression dependent on whether maternal or paternal genes in pair of chromosomes is switched on or off
What happens in autosomal dominant conditions?
1 parent has abnormal gene (or both) 50 % chance getting it
What happens in autosomal recessive conditions?
Both parents carriers- affected mother?= all children carriers
What is X linked inheritance?
recessive affected males + carrier females= all daughters of affected dads= carrier- never from father-son
What are the environmental influences affecting growth development?
physical, chemicals, radiation, drugs, infections
How is downsyndrome diagnosed?
Mother blood test
