3.1

Question 1

genome

Answer 1

the whole of the genetic information of an organism

Question 2

gene

Answer 2

short stretch of DNA that influences a specific characteristic

Question 3

allele

Answer 3

the various, specific forms of a gene that usually vary from each other by 1 or a few bases

Question 4

gene locus

Answer 4

the specific position of a gene on a chromosome

Question 5

diploid state

Answer 5

having a pair of each kind of chromosome

Question 6

haploid state

Answer 6

having 1 copy of each chromosome

Question 7

outline the hierarchy of genetic information from biggest to smallest and briefly define each one of them

Answer 7

genome-> chromosome-> genes-> allele

genome: has entire set of chromosomes of an organism
chromosomes: long DNA molecules, contains many genes
genes: short stretches of DNA, usually code for 1 characteristic
allele: a specific form of a gene

Question 8

Homozygous

Answer 8

have 2 copies of the same allele

Question 9

Heterozygous

Answer 9

have 2 different alleles

Question 10

Genotype

Answer 10

the alleles you have for a gene

Question 11

Phenotype

Answer 11

trait you have as a result of alleles

Question 12

Mutation

Answer 12

• changes in DNA sequence
• creates new alleles
• daughter cells contain DNA that differs from the DNA in the parental cell

Question 13

causes of mutations

Answer 13

DNA replication mechanism (mistakes), exposure to radiation+chemicals (aka mutagen)

Question 14

effects of mutations

Answer 14

• cause bases to be deleted/added to DNA sequence

- cause a different nitrogenous base to be used at a particular place

Question 15

base-substitution mutation

Answer 15

mutation that changes one nitrogenous base in a sequence

Question 16

effects of a base-substitution mutation

Answer 16

if an amino acid is changed, the polypeptide formed might work different or not at all. At the same time, it is possible that the amino acid sequence may still stay the same.

Question 17

human genome project

Answer 17

aim to determine the complete sequence of the human genome and identify every gene it contains

Question 18

how many bases estimated in the human genome?

Answer 18

3.2 billion bases

Question 19

what did genetic sequencing develop

Answer 19

drought-resistant crops, antimalarial medicine, bacteria that consumes toxic waste

Question 20

what is average human gene size?

Answer 20

2000 base pairs

Question 21

sickle cell anemia

Answer 21

common genetic disease where malaria is endemic (commonly found)

Question 22

symptoms of sickle cell anemia

Answer 22

extreme pain, weakness, heart attack, stroke, pneumonia, bone malformation, death

Question 23

base substitution mutation in sickle cell anemia

Answer 23

GAG–> GTG in sense strand

Question 24

mRNA base sequence that’s transcribed in sickle cell anemia

Answer 24

GAG–> GUG

Question 25

change to sequence of a polypeptide in hemoglobin in sickle cell anemia

Answer 25

Glutamic acid--> valine (in 6th position)

Question 26

what happens once initial mutation occurred?

Answer 26

new allele is created

Question 27

what is hemoglobin

Answer 27

vital protein found in erythocrytes (red blood cells). It carries oxygen throughout the body.

Question 28

how is hemoglobin made

Answer 28

made from 2 copies of beta subunits combined with 2 alpha subunits and 4 heme groups

Question 29

when do problems occur in hemoglobin?

Answer 29

- low oxygen levels - turned to long fibres from Hb^s, which will cause: 1. severely reduces ability to carry oxygen 2. long fibres poke into cell membranae, distort its shape, give red blood cell characteristic curved 'sickle' appearance

Question 30

problems with the new shape of sickled red blood cells

Answer 30

1. can get stuck, clog blood vessels anywhere in the body 2. cause intense pain as blood supply fails 3. can have stroke

Question 31

consequence as a result of sickled cells must be broken down and eliminated from body

Answer 31

1. strains liver 2. cause shortage of functioning anemia (red blood cell) 3. damage bone structure (need make new red blood cells to replace it)

Question 32

pleiotropy

Answer 32

when 1 gene has multiple effects

Question 33

when does single cell amenia happen

Answer 33

person is homozygous for Hb^s so both alleles agree, all hemoglobin contains alternate beta subunit

Question 34

person with alleles Hb^A Hb^A

Answer 34

their hemoglobin won't ever polymerise, and their erythrocytes won't ever sickle so...normal hemoglobin, no sickling, no protection from malaria

Question 35

person with alleles Hb^A Hb^S

Answer 35

heterozygous carriers of sickle cell trait, protection from malaria

Question 36

person with alleles Hb^s Hb^s

Answer 36

homozygous altered hemoglobin, sickle cell anemia, no protection from malaria

Question 37

when is the exclusive condition for the sickling of cells?

Answer 37

when cells are infected by plasmodium falciprum (paraasite that cause malaria)

Question 38

homologous chromosomes

Answer 38

2 chromosomes of same length

Question 39

how many protein-coding genes in bacterium (escherichia coli)

Answer 39

4000

Question 40

how many protein-coding genes in human

Answer 40

20000

Question 41

how many protein-coding genes in rice

Answer 41

35000