Patterns of Inheritance Flashcards
One chromosome is inherited from the _________ and one is inherited from the _________.
mother
father
Males have two ____________ sex chromosomes: ___
Females have two __ chromosomes: ____
different
XY
X
XX
Homozygous:
Heterozygous:
Two same alleles.
Two different alleles.
What 2 things does the inherited disorder; cystic fibrosis, mainly affect?
Lungs
Digestive system
When inheriting cystic fibrosis, the lungs and digestive system _________________________.
So they become __________ with mucus.
produce too much mucus
clogged
Cystic fibrosis is caused by a ______________________ on chromosome 7.
The child must inherit ___________ of this faulty gene; one each from each of their parents.
faulty recessive allele
two copies
Polydactyl is caused by a ________________ of a gene.
dominant allele
Parents that do not have any alleles for polydactyly produced a child with polydactyly.
Explain how polydactyly suddenly occurred in this family:
Caused by a mutation during __________.
Causing a __________ in ______________________.
Causing a _______________________ to be produced.
meiosis
change
amino acid sequence
different specific protein
Antenatal testing analyses an individual’s DNA _____________________.
before they are born
What is neonatal testing?
A new born blood spot test where a sample of blood is taken from pricking a baby’s heel.
Pre-implantation genetic diagnosis (PGD) is used on embryos before implantation.
__________________ are used to stimulate the release of ___________________.
The eggs are ______________________ in a Petri dish. This is known as IVF.
Later, the cells are tested for the _________________________. Embryos that don’t contain the disorder allele are _________________________.
Fertility drugs
several eggs
collected and fertilised
disorder-causing alleles
implanted into the uterus
What is a false positive?
A genetic test that wrongly detected a certain allele or faulty chromosome.
What is a false negative?
A genetic test that has failed to detect a certain allele or faulty chromosome.
The steps of gene therapy:
- ___________ the gene involved in the genetic disorder.
- Use __________________ to cut out the normal allele
- ________________ of the normal allele are made.
- Copies of the _______________________ are put into the _______ of the person who has the genetic disorder.
Identify
restriction enzymes
Many copies
normal working allele
cells
What are 3 problems with gene therapy?
- Alleles may not go into ____________________.
- The alleles may be inserted into the chromosomes at ________________.
- Some treated cells may be __________________ by the patient’s own untreated cells through ______________.
every target cell
random places
replaced naturally
mitosis
