Chapter 6. Matters of Sex. QSR #2. 1. A trait that is __________________, will be found mostly in males while ___________________ traits will be spread out evenly between males and females. 2. _________________ are the tips of the chromosomes – only about 5% of the entire chromosome.
Matters of Sex
1. Does a dominant or recessive allele produce the trait? Explain. 2. Is it autosomal or sex-linked? Explain. 3. What are the genotypes of all the individuals in the pedigree? (Write them on the pedigree.) 4. What is the genotype of individual IV-2? Explain. 5. What is the genotype of individual IV-6? Explain. 6. What is the genotype of individual I-1? Explain
children together – no incest!!!!
Consanguinity: “shared blood”—family members may share certain traits or disorders
Infants with Tay-Sachs disease appear to develop normally for the first few months of life. Then, as nerve cells become distended with fatty material, a relentless deterioration of mental and physical abilities occurs. The child becomes blind, deaf, and unable to swallow. Muscles begin to atrophy and paralysis sets in. A much rarer form of the disorder which occurs in patients in their twenties and early thirties is characterized by unsteadiness of gait and progressive neurological deterioration. Patients with Tay-Sachs have a "cherry-red" spot in the back of their eyes. The condition is caused by insufficient activity of an enzyme called hexosaminidase A that catalyzes the biodegradation of acidic fatty materials known as gangliosides.
Brain disorder – causes the “forgetting” of things previously learned
-- very similar symptoms to Autism
--only found in female – WHY?
Missing piece of X chromosome
Mental retardation, large ears, elongated face
Mitochondria contain their own DNA – but only the mother can pass down mitochondrial DNA to her offspring
Telomeres: tips of the
3. Females: traits on the X chromosome have to come in ______ copies to show up
4. Males: traits on the X chromosome only have to come in _____ pair
5. The male is said to be _____________for X-linked traits since they only need 1 copy
6. Explain the main difference between a hermaphrodite and a person who is trasngender.
Ichthyosis: an enzyme deficiency
blocks the removal of cholesterol
from skin cells – upper skin can’t
peel off causing a brown scaly