Genetics (Genetic Disorders + Reproductive Technologies) - Unit 2

Question 1

Disorders are identifiable from karyotype charts. Explain how they work?

Answer 1

• Karyotype charts have chromosomes arranged according to size, length, centromere location, and banding pattern
• Size is aligned in decreasing order
• Sex pair is always placed last
• In high risk pregnancies, detect chromosomal mutations, genetic disorders and malformations in spine and brain
• The sampled cells are cultured then treated to stop dividing during metaphase of mitosis
• Cells are stained and examined under a microscope

Question 2

What is Down’s syndrome?

Answer 2

• Trisomy 21
• Facial feature pattern, short stature, heart defects
• Respiratory disease, shorter lifespan
• Sexually underdeveloped and sterile
• Mentally affected
• Correlated with age of mother or nondisjunction of father’s chromosome 21

Question 3

What is Patau’s syndrome?

Answer 3

• Trisomy 13
• Cleft lip
• Eye and brain circulatory defects
• Hard to live after a few months

Question 4

What is Edward’s syndrome?

Answer 4

• Trisomy 18
• Affects every organ system
• Live no longer than a few months

Question 5

What is Klinefelter’s syndrome?

Answer 5

• Trisomy in sex chromosomes XXY
• Male sex organs, small testes, sterile
• Breast enlargement and wider hips
• No mental effects

Question 6

What is Jacob’s syndrome?

Answer 6

• Trisomy XYY
• May be taller than average
• Common skin conditions, severe acne

Question 7

What is Turner’s syndrome?

Answer 7

• Missing X chromosome, only in females
• Only 45 chromosomes
• Webbed neck
• Sterile
• Short stature
• Normal intelligence
• Most fetuses die before birth

Question 8

What is Triple X?

Answer 8

• XXX trisomy
• Tall and thin
• Menstrual irregularity

Question 9

What is Cri-du-chat?

Answer 9

• Deletion in 5
• Cleft palate
• Syndactyly (two fingers stick together)
• High pitched cry

Question 10

What is Charcot-Marie Tooth disease?

Answer 10

• Duplication in 17
• Muscle weakness
• Loss of sensation in lips

Question 11

What is FG syndrome?

Answer 11

• Inversion in X chromosome
• Exclusively in males
• Intellectual disabilities
• Broad toes and thumbs
• Low muscle tone

Question 12

What is Chronic Myelogenous Leukemia?

Answer 12

• Translocation between 9 and 22, forming an abnormal gene
• Causes cancer of white blood cells
• Treated with drug that stops the increased production of white blood cells

Question 13

What is selective breeding?

Answer 13

• The process of breeding plants and animals for desirable traits
• Used in traditional agriculture but is imprecise due to a combination of many genes
• Can produce many plants and animals such as Appaloosas

Question 14

What is artificial insemination?

Answer 14

• Process of collecting sperm and concentrating it and introducing it into the female reproductive system
• Pros: makes high-quality male semen more available and able to choose desirable traits for male parent

Question 15

What is embryo transfer?

Answer 15

• Process which an artificially fertilized egg is transferred into a recipient female
• Pros: shipping of eggs is easier compared to shipping the physical animal, can benefit the animal which is born into the environment and not shipped

Question 16

What is in vitro fertilization?

Answer 16

• IVF, a reproductive solution for women with blocked fallopian tubes
• Used to fertilize egg cells outside of the body
• Creates test tube babies because they are conceived in lab glassware
• Also used for parents with history of genetic disorders
• Preimplantation genetic diagnosis is the process done before the IVF is performed to test the embryos of genetic disorder
• After a healthy conclusion, the embryos are then planted in the uterus
• Ethical and social debates, possible abuse of this technology and concerned limit

Question 17

What is cloning?

Answer 17

• Generally defined as a process that produces identical copies of genes, cells, organisms
• Gene cloning is the manipulation of DNA to produce multiple copies of a gene or segment of DNA
• Recombinant DNA is a molecule of DNA that includes genetic material from diff sources used to create transgenic organisms
• Therapeutic cloning is replacing an egg cell’s nucleus with the nucleus from a somatic donor cell to produce a cell line of genetically identical cells,
  > ex. grow new tissues and organs
• Reproductive cloning is the production of a genetically identical organism, raises concern in ethics

Question 18

What are transgenic organisms?

Answer 18

• Insertion of foreign DNA into plants and animals to produce transgenic organisms (organisms with genetic material and DNA of different species)
• GMO is an organism that has the sequence of its genome altered for a specific purpose
• Increases resistance to herbicides for transgenic plants and viruses
• Transgenic milk-producing animals can produce medical protein products that include human growth hormones and anti-clotting factors
• Can possibly also be organ donors
  > cons: risk of disease transfers and ethics regarding animal cruelty