Lab 5: Karyotype and Genetics

Question 1

human karyotype

Answer 1

display individuals xsomes arranged in homologous pairs

Question 2

How is a human karyotype prepared

Answer 2

1. Photograph a cell during mitosis (metaphase)
2. Put picture into a computer for analysis
3. Electronically arrange the xsomes into pairs (according to size and centromere position)

Question 3

Do you know why it might be necessary to prepare a karyotype?

Answer 3

allows detection of many chromosomal abnormalities (missing or extra)

Question 4

Metacentric

Answer 4

centromere is in middle of chromosome

Question 5

Subterminal

Answer 5

between middle and end

Question 6

Acrocentric

Answer 6

located close to one end

Question 7

nondisjunction

Answer 7

Extra chromosome (21st pair b/c xsome fail to separate
- Occurs in Anaphase I where both members go to one pole
- Meiosis II where sister chromatids fail to separate in anaphase II and both chromatids go to one pole

Question 8

how does non disjunction result to genetic problems

Answer 8

results in the production of gametes containing a greater or lesser chromosomal amount than normal ones

Question 9

Down Syndrome

Answer 9

extra chromosome one 21st pair

Question 10

Patau syndrome

Answer 10

extra chromosome on 13th pair

Question 11

Edwards syndrome

Answer 11

extra chromosome on 18th pair

Question 12

Turner syndrome

Answer 12

female w/ only one X
- Female sex organs do not mature, menstruate, sterile

Question 13

Klinefelter’s syndrome

Answer 13

male having XXY
- Phenotypically male but possess female body features

Question 14

Cri-du chat

Answer 14

Deletion of tip of one of 5th chrosomosomes
- cries like a cat

Question 15

steps of solving genetic problems

Answer 15

1. Define alleles
2. determine genotypes of parents and types of gametes produced
3. use punnett square
4. express result

Question 16

Genetics

Answer 16

Studies relationships b/w genes and chromosomes

Question 17

Locus

Answer 17

position of a gene on chromosome

Question 18

Alleles

Answer 18

alternate forms of same gene (A and a) found at same locus on homologous chromosomes (codes different phenotype)

Question 19

First Filial (F1) Generation

Answer 19

offspring resulting from crossing of individuals of parental generation

Question 20

Second Filial (F2) Generation

Answer 20

offspring resulting from crossing F1 members

Question 21

monohybrid cross

Answer 21

examines inheritance of a single trait

Question 22

dihybrid cross

Answer 22

examines inheritance of 2 diff trains on 2 diff pairs of homologous chromosomes

Question 23

Incomplete Dominance

Answer 23

Neither allele is dominant
When result is hetero it shows a third phenotype

Question 24

Multiple Allele inheritance

Answer 24

Some genes show more than 2 alternate forms such as ABO blood types (IA, IB, i)

Question 25

Polygenic inheritance

Answer 25

Multiple alleles act together to get a characteristic (skin, height, eye)

Question 26

Sex linked inheritance

Answer 26

Sex-linked diseases are inherited through one of the sex chromosomes, which are the X and Y chromosomes.

Question 27

pedigree

Answer 27

Diagram of family history using symbols to
show relationships (genetic variants, traits, diseases)