Human Genome

Question 1

How many base pairs does a Human Genome have?

Answer 1

Over 3 billion

Question 2

How many pairs of chromosomes does a human genome have?

Answer 2

23 pairs

Question 3

How many homologous pairs does a genome have?

Answer 3

22 (sex chromosomes). Females contain 23

Question 4

What is a karoytype?

Answer 4

A picture of all of the chromosomes arranged in order of decreasing size

Question 5

How many genes are in an X chromosome?

Answer 5

Over 1400 genes

Question 6

How many genes are in Y chromosome?

Answer 6

About 158 genes, but many repeat so theirs only 50 or so.

Question 7

X chromosome

Answer 7

Essential for life does not influence sex; two equal female

Question 8

Y chromosome

Answer 8

Not needed for life. SRY gene causes an embryo to be a male

Question 9

Barr Body

Answer 9

Genes that are switched off in one of the X chromosomes. Males have only one X so no Barr body is formed.

Question 10

Nondisjunction

Answer 10

When homologous chromosomes do not seperate as they should

Question 11

Nondisjunction in meiosis I

Answer 11

Results in four abnormal cells

Question 12

Nondisjunction in meosis ii

Answer 12

Two of the cells will be abnormal chromosomes

Question 13

When a cell has an extra chromosome and is united with a normal gamete

Answer 13

Trisomy

Question 14

When a cell is missing a chromosome and is united with a normal gamete

Answer 14

Monosomy

Question 15

Down syndrome

Answer 15

Results in three copies of chromosome 21

Question 16

Cat Eye syndrome

Answer 16

Three copies of 22

Question 17

Patau Syndrome

Answer 17

Three copies of 13

Question 18

Edward Syndrome

Answer 18

Extra chromosome in 18

Question 19

William syndrome

Answer 19

Monosomy in chromosome 7

Question 20

Cystic Fibrosis

Answer 20

Results in the deletion of just theee bases. Bases removed a single amino acid causes protein to fold improperly. One copy is no problem because the cystic fibrosis transmembrane conductance regulator (CFTR) allow it to work properly. 2 copies produce a disorder.

Question 21

Restriction enzyme

Answer 21

Enzyme that cuts DNA at a sequence of nucleotides

Question 22

Genomic printing

Answer 22

Process in which epigenetic chemical marks can be passed from one generation to the next in a sex-specific way.

Question 23

Gel electrophoresis

Answer 23

Procedure used to seperate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electric voltage to the gel.

Question 24

What do restriction enzymes make possible?

Answer 24

They make it possible for scientists to cut, seperate, and copy nucleus acids so scientists are able to read DNA base sequences.

Question 25

What are overhangs that can bond with the complementary base sequence?

Answer 25

Sticky ends

Question 26

How does reading DNA work?

Answer 26

Single-stranded FNA fragments are placed in a tube containing DNA polymerase and four nucleotide bases, A, T, G, and C. The enzyme then uses the unknown strand as a template to make one new DNA strand after another. They also add bases with chemical dye attatched. Each time one’s added to the new DNA strand, the synthesis of the strand stops. The result is color coded DNA fragments of different lengths. Scientists then seperate the fragments.

Question 27

What is the shotgun sequencing method?

Answer 27

Chromosomes are cut into random fragments which are then sequenced automatically in a computer. Computers find overlapping sequences and determine the sequence for the entire dna.

Question 28

How many genes does a human cell have?

Answer 28

About 20,000

Question 29

What are single base differences between members of the same species?

Answer 29

Snips (single nucleotide polymorphism)