bio final part B

Question 1

stages in mitosis

Answer 1

prophase:
1. chromatin condense to chromosome
2. nuclear envelop and nucleolus disappear
3. centrosome separate and form spindle fibre

metaphase:
1. each centrosome reach a pole
2. chromosome line up across the metaphase plate(equator)
3. spindle fibre attached to chromosome

anaphase
1. chromosome separate become 2 chromatid
2. chromatid move to opposite end of the cell

telophase
1. chromatid unfold back to chromatin
2. new nuclear envelope formed

Question 2

centriole in animal vs plant cells

Answer 2

centriole are found in animal cell, absent in almost all plant cell (found in some lower plant cell)
-centriole contain 2 cylindrical structure
-used for spindle fiber formation (plant cell have spindle fibre outside the nuclear envelope so no need centriole during cell division)

Question 3

role of mitosis

Answer 3

1. growth of multicellular organism
2. replacement of cell and repair of tissues
3. asexual reproduction
4. immune respond

Question 4

effect of drug in treating cancer

Answer 4

chemotherapy
-kill fast growing cell (involving cancer cell and healthy white blood cell) by damage the gene inside the nucleus of cell
-fewer normal white blood cell to fight pathogens (will get infection easily)
-permanent damage to heart, lungs, liver,….

Question 5

features in prophase, metaphase and interphase

Answer 5

interphase:
G1 : cell make RNA, enzyme and other protein needed for growth
S: signal for another cell division received, DNA replication occur
G2: cell continue to growth, new DNA checked, repair error and increase production of tubulin

prophase:
1. chromatin condense to chromosome
2. nuclear envelop and nucleolus disappear
3. centrosome separate and form spindle fibre

metaphase:
1. each centrosome reach a pole
2. chromosome line up across the metaphase plate(equator)
3. spindle fibre attached to chromosome

Question 6

protein related to DNA

Answer 6

1. protein histone - bind to DNA, give chromosome shape and control the activity of gene
2. DNA control protein synthesis (transcription: transcribing a piece of dna into rna) (translation: convert mrna code into amino acid sequence within a protein)

Question 7

function of spindle fibre in mitosis

Answer 7

-spindle fibre attach to chromosome during metaphase
-separate chromosome and pulls the chromatid towards opposite poles during anaphase
-allow 2 daugther cell to be completely identical

Question 8

importance of cell cycle and effect of failed cell cycle

Answer 8

importance:
1. dna duplication and produce 2 genetically identical daughter cell
2. maintain normal metabolic function
3. gamete formation
4. repair and regenerate damaged cell

effect of failed cell cycle:
1. uncontrolled mitosis (cancer)
2. mutation - early cell death
3. not passing genetic information
4. no cell growth/reproduction
5. not able to replace damaged cell

Question 9

stages on protein synthesis

Answer 9

transcription:
1. transcribing a piece of DNA into RNA

translation:
1. synthesis of protein from mRNA template
2. convert mRNA code into an amino acid sequence within a protein

Question 10

process of transcription

Answer 10

site of transcription=nucleus
1. part of DNA unwind
2. mRNA use a single strand as template
3. 3 RNA nucleotide base joined together by enzyme RNA polymerase
4. enzyme RNA polymerase continuously add nucleotide to the growing mRNA strand
5. at stop codon, the H-bond that hold the DNA-RNA sequence are broken
6. double stranded DNA reform
7. mRNA leave the nucleus via nuclear pore

Question 11

structure of tRNA and its function in translation

Answer 11

L-shape structure
single stranded
contain 1 amino acid attachment, D-loop, T-loop, anticodon loop(triplet of bases)

function:
1. carry specific amino acid to the ribosome to build protein
2. acts as link between the genetic code in mRNA and the amino acid that make up protein

Question 12

mRNA vs DNA

Answer 12

mRNA and DNA
nucleotide as monomer
posses 4 nitrogenous bases
exhibit a phosphate backbone

mRNA
has ribose
single stranded structure
has uracil as nitrogen base
carries information from DNA to ribosome

DNA
has deoxyribose
double stranded structure
has thymine as nitrogen base
holds genetic information for the protein

Question 13

state purine bases

Answer 13

adenine (pair with thymine/uracil)
guanine (pair with cytosine)
#pair with pyrimidines

Question 14

anticodon on tRNA

Answer 14

adenine, guanine, uracil, cytosine

located at one end of tRNA molecule
trinucleotide sequence
complementary to codon
has uracil replacing thymine in DNA

Question 15

hydrogen bond between mRNA and tRNA anticodon

Answer 15

(between codon and anticodon)
breaks when reach stop codon

Question 16

calculate percentage of bases in DNA

Answer 16

Chargaff’s rule
A=T, G=C
A+T+G+C=100%

Question 17

bonding between amino acid in translated polypeptide

Answer 17

peptide bond

Question 18

identify dominant allele

Answer 18

always expressed in phenotype in both heterozygous and homozygous
written as uppercase letter

Question 19

codominance

Answer 19

both allele can be expressed in the phenotype at the same time
exp. blood type

Question 20

genetic diagram of codominance

Answer 20

parents phenotype : A B
parents genotype: IAIO IBIO
gamete genotype: (IA) (IO) (IB) (IO)
offspring genotype IAIB IOIB IAIO IOIO

Question 21

compare haploid and diploid cell

Answer 21

1. haploid contain 1 complete set of chromosome(n) while diploid contain 2 complete set of chromosomes(2n)
2. haloid cell has 23 chromosome in nucleus while diploid cell has 46 chromosome
3. haploid cell involved in sexual reproduction while diploid contain DNA necessary for protein synthesis and cell function
4. example of haploid cell is gamete such as sperm and egg while diploid cell is somatic cells such as nerve and muscle

Question 22

type of isolation

Answer 22

pre-zygotic (temporal, ecological, behavioral, mechanical)
–prevent gamete of 2 individual from fusing to form a zygote

post-zygotic (hybrid inviability, hybrid infertility, hybrid breakdown)
–prevent development of a fertile individual from a zygote

Question 23

process of isolation

Answer 23

temporal – 2 species mate at different times of year. exp. breed during summer/spring

ecological – 2 species occupy different habitat. exp. lion and tigers

behavioral – 2 species have different courtship behaviors. exp. certain group of bird only respond to species-specific mating calls

mechanical – physical different prevent copulation/pollination. exp. certain breed of dog morphologically incapable of mating due to size

hybrid inviability – hybrid produced but fail to develop to reproductive maturity. exp. certain type of frog from hybrid tadpoles die before the become a frog

hybrid infertility – hybrid fail to produce functional gametes. exp. mules are sterile hybrid resulting from mating between horse and donkey

hybrid breakdown – F1 hybrid fertile but F2 generation does not develop properly. exp. offspring of hybrid copecods have less potential for survival and reproduction.

Question 24

importance of natural selection

Answer 24

1. lead to speciation (1 species give rise to a new and distinctly different species)
2. increase the chance of survival
3. adapt to the environment

Question 25

advantage using mtDNA in studying closeness in between species

Answer 25

1. no crossing over
2. faster mutation
3. constant mutation
4. smaller/fewer gene in mtDNA

Question 26

why length is identified as continuous variation

Answer 26

1. length is quantitative variable
2. no distinct categories
3. within a range between 2 extreme
4. may cause by gene and environment

Question 27

how natural selection occurred in choosing longer/shorter feature

Answer 27

environment—dense forest: shorter; open grassland: longer limb for running

reproductive success— longer: more attractive

Question 28

calculate percentage of heterozygous population(2pq) using Hardy-Weinberg equation

Answer 28

p+q=1

p= frequency of dominant allele
q= frequency of recessive allele

p2+2pq+q2=1

p2=chance of being homozygous dominant
q2=chance of being homozygous recessive
2pq=chance of being heterozygous