Flashcards in Environment and Genetics Deck (57)
What type of bases is DNA made up of?
Purine Bases (Adenine and Guanine)
Pyrimidine bases (Cytosine and Thymine)
What base does Adenine always pair with?
Thymine (replaced by Uracil in RNA)
What does Guanine always pair with?
The study of the transmission of single genes within families and the analysis of more complex of inheritance
The study of genes and their function. Genomics aims to understand the structure of the genome, including the mapping genes and sequencing the DNA.
What is the difference between genetics and genomics?
Genomics is better because it is tailored for each person's unique needs and it can help find a treatment that is maximally effective
How many pairs of chromosomes are there in humans?
How many pairs of autosomes are there in humans?
How many pairs of sex chromosomes are there in humans?
What are congenital anomalies or disorders?
disorders present at birth
What are the types of congenital anomalies/disorder?
Define Single-gene disorders
A trait controlled by one set of alleles that is transmitted to subsequent generations
What do single genes control?
Specific functions (color blindness)
What are the 4 types of single-genes?
1. autosomal recessive
2. autosomal dominant
3. x-linked recessive
4. x-linked dominants
What classifies an autosomal recessive disorder?
both parents must pass on the allele for the disorder
What is the term used to define parents who are heterozygous for a disease and unaffected?
Are homozygous parents affected?
Give examples of autosomal recessive single-gene disorders
1. cystic fibrosis
3. Tay-sachs disease
What classifies an autosomal dominant disorder?
When the parent has the dominant allele. Only one parent needs to have the allele to pass it on.
Are there any carriers for the autosomal dominant disorders?
No, anyone who has the dominant allele is affected
Why are autosomal dominant disorders termed delayed lethal genotypes?
The allele for the disorder may have been passed on to the next generation before diagnosis of the disease in a parent because symptoms may become evident later in life.
Give examples of Autosomal dominant disorders
1. Adult polycystic kidney disease
2. Huntington disease
3. Familial hypercholesterolemia
4. Marfan syndrome
What is Marfan Syndrome?
When someone has long limbs, large hands and feet, and their hearts give out
What classifies an X-linked recessive disorder?
A disorder that comes from the mother's side. It is manifested in heterozygous males lacking the matching unaffected gene on the Y chromosome. It may appear to skip generations.
Who are the carriers for X-linked recessive disorder?
Who are affected by X-linked recessive disorders?
Homozygous recessive females
Give examples of X-linked recessive disorders
Duchenne muscular dystrophy
What are X-linked dominant disorders?
Dominant disorders that are carried from the females
Who are affected by X-linked dominant disorders?
Heterozygous males and females