Genetic Variation

Question 1

What are tandem repeats?

Answer 1

Can be up to several thousand nucleotides and present next to eachother in identical or near identical copies

Question 2

What are simple sequence repeats?

Answer 2

Can be as short as 2 nucelotide sequences and repeated over and over

Question 3

What are DNA polymorphisms?

Answer 3

-One of 2 or more alternative forms (alleles) at a chromosomal region (locus)
-Can differ by 1 nucleotide or repeats
-Mostly found in noncoding regions
-Used as DNA markers for analysis

Question 4

It is extremely __________ any ____________ individuals have the same variable number of tandem repeats (VNTRs)

Answer 4

unlikely, unrelated

Question 5

_______ variations occur in noncoding regions

Answer 5

silent

Question 6

What is the cause of sickle cell anemia?

Answer 6

-Genetic variation in beta globin alleles
-SCA is due due being homozygous for the HbS allele
-Individuals can not make functional beta globin proteins
-Cells are sickle shaped and prone to clotting, poor at carrying oxygen, and cause acute pain and fatigue

Question 7

In microarray, greater _______ means more _______

Answer 7

fluorescence, gene copies

Question 8

How many haploid sperms cells does a male produce through meiosis?

Answer 8

4 haploid sperm cells from one sex precursor

Question 9

How many haploid egg cells does a female make from one sex cell precursor?

Answer 9

1 large egg and 3 polar bodies (polar bodies are small and only present to reduce chromosome content and keep it haploid)

Question 10

What happens in prophase I

Answer 10

-Chromosome condensation
-Synapsis (pairing) of homologous chromosomes facilitated by synaptonemal complex
-Crossing over

Question 11

What happens in metaphase I

Answer 11

-Homologous chromosome bivalents become randomly arranged relative to eachother at metaphase plate by microtubules

Question 12

What happens in anaphase I

Answer 12

-Proteins holding homologous pairs together break down
-Pairs are separated to opposite poles
-Sister chromatids do not separate

Question 13

What happens in telophase I

Answer 13

-Each cell has a haploid set of chromosomes
-Each chromosome is a pair of recombinant sister chromatids
-Followed by cytokinesis and meiosis II

Question 14

Meiosis is often referred to as __________ _____________ because the cells have the same number of chromosomes as all gametes produced at the end of meiosis II

Answer 14

equational division

Question 15

_______________ happens when a pair of homologous chromosomes fail to separate in meiosis I or II

Answer 15

Nondisjunction

Question 16

Mendel bred ___________ parent plants, they would only produce certain traits over many ___________

Answer 16

true breeding, generations

Question 17

In mendels peas, __________ and ___________ were dominant traits

Answer 17

yellow, smooth

Question 18

When F1 was allowed to self pollinate, they did not _____________, they bred _________________ ______

Answer 18

breed true, dominant-recessive 3:1

Question 19

What is mendels law of segregation?

Answer 19

2 alleles of a gene segregate intp different gametes during gamete formation in both parents
Offspring inherits 2 alleles for a gene, dominant allele determines the phenotype

Question 20

What is Mendels law of independent assortment?

Answer 20

-The alleles of 2 or more different genes get sorted into gametes independently of one another
-Only applies to allele pairs on different chromosomes
_dependent on nonhomologous chromosome alignment during meiosis I
-If genes are located on the same gene, they will not show independent assortment and may be linked if they are close enough together

Question 21

What is another name for nondisjunction?

Answer 21

Aneuploidy

Question 22

What is klinefelter syndrome?

Answer 22

XXY, 47
Tall, feminized physique, breast development, less body hair, sterile, small testes

Question 23

what is trisomy 21

Answer 23

down syndrome, 47, 21+

Question 24

what is trisomy 13?

Answer 24

patau syndrome, 47, 13+
cleft palate, deaf, malformed organs

Question 25

what is trisomy 18?

Answer 25

Edwards syndrome, 47, 18+
Small birth weight, low ears, webbed neck, receding chin, malformed organs

Question 26

What is Turner syndrome?

Answer 26

45, XO
short stature, webbed neck, shield like chest, immature sex organs, sterile

Question 27

What is Triple X syndrome?

Answer 27

47, XXX
Normal phenotype, tall, fertile, menstrual irregulation, learning disabilities

Question 28

What is Jacobs syndrome?

Answer 28

XYY, 47
Tall, fertile, normal intelligence