Interview part 2 Flashcards
(15 cards)
What is the structure of chromosomes?
Chromosomes are composed of satellite DNA (non-coding part) and DNA (which is only a very little part).
What is karyotyping?
In Karyotyping you see a picture on how the homologous chromosomes are arranged, there you can determine if any non-disjunction (if the chromosome pairs had failed to separate) has occurred.
How are the chromosomes arranged in karyotyping?
The homologous chromosomes are rearranged according to their size, structure and charge
Ressesive gene
genes that only have an effect (on phenotype, proteins etc.) when present in a homozygous state
Dominant gene
genes that have the same effect (on the phenotype, proteins etc.) whether it is present in a homozygous of heterozygous state
Sex-linked traits
the association of a characteristic with gender, because the gene controlling the characteristic is located on a sex chromosome. Some genes are present on the X-chromosome and absent from the shorter Y-chromosome in humans.
Sex determination
It can be determined in a karyotype. The sex of an offspring depends on which chromosome it gets from the father. If it is a girl it has XX and if it is a male it is XY.
State the factors which are influencing gene espression
Chemicals, temperature, drugs, codon usage (some tRNA are not as common)
Describe Down´s syndrom
- It is a disease in which the chromosomes fail to separate properly during meiosis (anaphase I or anaphase II) leading to 3 chromosomes of pair 21 instead of 2.
- A person with the condition has in total 47 chromosomes instead of 46. The non-disjunction can take place either in the formation of the egg or the sperm. The risk of getting children with the disease increases with age.
Describe Turner´s syndrom
- Turner syndrome is a chromosomal condition that affects development in females.
- An early loss of ovarian function is also very common. The ovaries develop normally at first, but egg cells (oocytes) usually die prematurely and most ovarian tissue degenerates before birth. Many affected girls do not undergo puberty unless they receive hormone therapy, and most are unable to conceive (infertile).
- Turner syndrome results when one normal X chromosome is present in a female’s cells and the other sex chromosome is missing or structurally altered. The missing genetic material affects development before and after birth.
Describe Klinefelter´s syndrom
- Klinefelter syndrome, also known as the XXY condition, is a term used to describe males who have an extra X chromosome in most of their cells.
- Symptoms depend on how many XXY cells a man has, how much testosterone is in his body, and his age when the condition is diagnosed.
- As XXY males enter puberty, they may have a taller, less muscular body, less facial and body hair, and broader hips than other boys. As teens, XXY males may have larger breasts, weaker bones, and a lower energy level than other boys.
- XXY males can have normal sex lives, but they usually make little or no sperm and are infertile
Describe colourbindness
It is the inability to differentiate certain colors. The most common being red green color blindness. There are multiple causes, but color blindness is primarily inherited by way of a mutated X Chromosome. Due to the fact that men only have one X chromosome, if they are handed a faulty X chromosome (by a carrier mother) they will be color blind. Women on the other hand have two X chromosomes, which is why many less women are color blind than men. The odds that both X chromosomes are faulty is extremely low, and the healthy one will take precedence providing normal perception of color.
Describe hemophilia
- is a rare disorder in which your blood doesn’t clot normally because it lacks sufficient blood-clotting proteins (clotting factors).
- Hemophilia is an inherited (genetic) disorder. There’s no cure yet.
How are the mitochondrion inheritate?
Mitochondria are inherited only in the maternal ova and not in sperm. Therefore, a pattern of inheritance associated with alterations in mitochondrial DNA gives a pattern of the condition affecting males and females, but always being maternally inherited. An affected male does not pass on his mitochondria to his children, so all his children will be unaffected. This is called mitochondrial inheritance.
When a child of a family has a mitochondrial desease or abnormality, what does this show?
This shows that the child has got a mitochondrial disprder or desease from their mother. The father can never pass on his mitochondrion to its children.
