Lecture 4

Question 1

Is sex determination the same in all organism? (know the answer and anything else we discussed regarding this question)

Answer 1

No.

Question 2

Usually only ______________ (number) is activated in each female mammal. Fill in the blank.

Answer 2

1

Question 3

The inactivated X chromosome of a female is highly condensed making it visible as an intensely staining ______________ attached to the nuclear membrane. Fill in the blank.

Answer 3

Barr Body

Question 4

Females that are heterozygous for X chromosome alleles are ______________. Their individual cells may express different alleles, depending on which chromosome is inactivated. Fill in the blank.

Answer 4

Genetic Mosaics

Question 5

Regarding changes in chromosomes, what is disjunction?

Answer 5

Disjunction is when chromosomes separate in a cell during cell division.

Question 6

What is the definition of (a) aneuploidy, (b) monosomy, or (c) trisomy?

Answer 6

Trisomy = 47
Monosomy = 45
Aneuploidy = Genetic disorder where chromosomes don’t equal 46.

Question 7

Which statement accurately describes how someone would receive either (a) sickle-cell disease, (b) hemophilia, or (c) Huntington’s disease?

Answer 7

Huntingtons = Dominant Trait
Hemophilia = Sex-linked recessive
Sickle-Cell disease = Heterozygous or both

Question 8

According to the video Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis, what is the definition of codominance?

Answer 8

Codominace is when the alleles work together. (Hence “co”)

Question 9

According to the video Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis, what would be the color of chicken offspring of BB (black) and WW (white) parents following codominance genetic rules? Why does this occur?

Answer 9

They would be both black and whites (speckled) because both traits show up which is the essence of codominance.

Question 10

According to the video Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis, what are polygenic traits?

Answer 10

Many genes coding for one trait.

Question 11

According to the video Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis, both height and skin color can be influenced by ___________ factors. ____________ can affect your height and spending a lot of time in the sun can affect your ___________. However, it cannot affect your genetics for a trait. Fill in the blanks.

Answer 11

1. Environmental
2. Nutrition
3. Skin Color