Bio Exam 3 Chapter 13

Explain the difference between autosome and sex chromosome?

Autosomes= chromosomes that don't carry any genes that determine the sex of the individual. Sex chromosomes= carry sex-determining genes (but may also carry many other genes that have nothing to do with sex). There is one pair of sex chromosomes (X & Y in mammals); all the rest (22 pairs in humans) are autosomes.

Explain the difference between crossing over and dosage compensation?

Crossing over (recombination) - prophase 1 : mixing up gene pool Dosage compensation - women BAB body becomes inactivated

How is the sex of a human determined? How about with the Drosophila?

If there's a Y chromosome Dros=n Drosophila, sex determination is achieved by a balance of female determinants on the X chromosome and male determinants on the autosomes. Normally, flies have either one or two X chromosomes and two sets of autosomes. If there is but one X chromosome in a diploid cell (1X:2A), the fly is male.

When do symptoms of Hunington disease occur?

In women aged between 35-40; neurological system problems

If an individual is XXY, is this person male or female? Name the genetic conditions?

Male=kleinfelter syndrome

What are Barr bodies? How many of them are found on the X chromosome of normal females?

One is found on the chromosome. Inactivates bad genes

Explain the difference between Prader-Will syndrome and Angelman syndrome?

Prader-Will is from the father and involves having learning disabilities as well as OCD (chromo. 15) Angelman syndrome is from the mother & it is more severe, processing problems and very aggressive behavior (chromo. 15)

What function does the SRY gene have? On which chromosome is this gene found?

SRY= allows for male characteristics. If missing gender neutral. Found on Y chromosome.

Explain the genetic difference between sickle cell anemia and hemophilia?

Sickle cell anemia - protein mutation, blood cells are mid formed, jagged edgesHemophilia - blood does not clot; sex linked in males

What is the chromosomal make up in Turners Syndrome?

XO missing one X in females males will self abort

Sex linked genes are determined by which chromosome?

Y chromosome