BIOL125 Lecture Notes - Lecture 3: Haemophilia, Hemoglobin A, Y Chromosome

23 views9 pages

jadeoyster197

27 Jun 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

BIOL week 3 LC  Cell division, genetics, and inheritance

REFERENCE  CHAPTER 3 AND 29 OF TEXTBOOK

DNA and RNA

- Large organic molecules known as nucleic acids

- DNA = deoxyribonucleic acid (in chromosomes in nucleus) 

genetic code that’s kept in chromosomes in the nucleus in

eukaryotic cells (cells like ours)

- RNA = ribonucleic acid (3 types of RNA in cells); RNAs

cooperate to code the DNA message and get required protein made

oMessenger  makes a copy of the gene sequence we want to make a protein

oRibosomal  helps make ribosomes

oTransfer RNA  brings correct amino acid to the ribosome, read messenger

RNA code and insert the amino acid so that we get the correct protein being

made

- DNA determines inherited characteristics eg: eye colour; controls body shape;

regulates metabolism, protein synthesis and enzyme production

- DNA encodes information to make proteins: 1 gene  1 messenger RNA  1 specific

protein made

Structure of DNA

- Two long chains of nucleotides in a double helix structure

- Nucleotide contains:

1. Pentose (5 carbon sugar) attached to both

2. Phosphate group

3. Nitrogenous base (ACGT)  A typically binds with T and G typically binds

with C

- Sugar of one nucleotide binds to the phosphate of another nucleotide  sugar-

phosphate backbone structure, with bases between the backbone

- Primary role of DNA: storage and transfer of information essential to synthesis of

proteins in body cells

- Sequence of nitrogenous bases determines amino acid order in a protein

- Information in genes, regulated by control sections of DNA

- A forms 2 hydrogen bonds with T

- G forms 3 hydrogen bonds with C

RNA structure

- RNA is typically single-stranded

- Where DNA has a T, RNA has a U for uracil

Chromosomes

- Very long DNA strands are tightly coiled into chromosomes, visible at replication.

Why is coiling needed?  by tightly coiling them up, we can package the DNA so that

it is protected against breakage during cell division

- 46 (2n/diploid) chromosomes, arranged as 23 pairs; one of each pair inherited

maternally, the other paternally; 22 pairs of autosomes, 1 pair of sex chromosomes;

some cases of extra or missing chromosomes survive to adulthood eg: Down

Syndrome (extra sex chromosome #21), Turner’s Syndrome (missing sex

chromosome)

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 9 pages and 3 million more documents.

Already have an account? Log in

- Sex chromosomes for female = XX, sex chromosomes

for male = XY

- Homologous chromosome pairs can be visualised in a

karyotype

- Homologous = one chromosome eg: #1 inherited from

mum plus the same chromosome (#1) inherited from

dad (for all 23 pairs)

- Chromosomes only become dense and super coiled at

cell division

Cell Division

- When preparing for division, the cell needs to duplicate

the DNA and package it up tightly into chromosomes to

protect it during the process of cell division

- Chromatin = very loosely coiled DNA  why? Because

the cell will need to open up the helix to make proteins

for its day to day activities

Genes and Alleles

- Gene  action/sequence of DNA which codes for a specific protein ie. Insulin gene

codes for insulin protein; each clotting factor gene codes for one specific factor

protein

- Genes are located along chromosomes  large chromosomes have more genes than

smaller chromosomes

- Genes  units of heredity ie. Determine our genotype therefore our phenotype

- Two of each chromosome/autosome (apart from sex chromosomes) therefore wo

copies of each gene, at same location on both chromosomes

- Different forms/sequences of the gene are known as alleles: which two alleles you

inherit (genotype) determine your phenotype (what you “look like” ie. Which

proteins are expressed)

- If genes are not vital for survival, mutation is more commonly occurring in these

forms of genes and can’t allow different forms

Genotype and Phenotype

- The two alleles carried for each gene determines genotype at each gene locus

(location on chromosome)

- One allele may be dominant to the others, which are therefore recessive: only 1

dominant allele needs to be present to “show” as the phenotype; while both alleles

must be recessive to express the recessive phenotype

- Multiple alleles known to exist for characters such as eye colour and ABO blood type

- Co-dominant alleles: two alleles both dominant over a recessive allele; both alleles

express protein product eg: ABO blood group

- Phenotype may be influenced by environment eg: you may carry hypersensitive

response genes but do not get allergies unless environmental stressors are present

(eg: chemicals or pollen)

Alleles Arise Via Mutation

- 2 identical alleles = homozygous at that gene locus (approximately 80% of a person’s

alleles are homozygous)

- 2 different alleles = heterozygous for that gene locus

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 9 pages and 3 million more documents.

Already have an account? Log in

- Alleles arise via mutation: mutation = change in the nucleotide sequence, sometimes

 different proteins

- Mutation is often lethal if it changes the required protein product so it cannot

perform its function; if not lethal, it stays in population as a new allele/version

- Mutations in major cell control genes may lead to cancer or death eg: p53 stops cell

growth and is a very important cell regulation gene; recognises damaged DNA and is

involved in DNA repair; and triggers apoptosis as a final resort for badly damaged

cells; approximately 50% of all human tumours have a mutated p53 gene

Apoptosis

- Cells have control mechanisms to prevent damaged cells from replicating themselves

 apoptosis or programmed cell death

- If these controls fail, cells with mutated DNA can survive and turn into cancer cells

- Apoptosis occurs normally during foetal development eg: when cells in the hands

and feet kill themselves  formation of separate fingers and toes

The Cell Cycle

- Mitosis consists of prophase, metaphase, anaphase and telophase

- Cytokinesis is where the new cell membrane forming and pinching off to separate

and form the two new cells

- In prophase, we get visualisation of the chromosomes – we can see them being

coiled and condensed

- In metaphase, the chromosomes line up across the centre or equator of the cell

- In anaphase, one of each of the chromosome sets is pulled to each end of the pole

- In telophase, we get new nuclear membranes forming

Cell Division

- Two types: mitosis and meiosis

- Mitosis occurs in somatic/body cells; provides an exact copy of the parent/dividing

cell

- Meiosis occurs in ovaries and testes to produce gametes/sex cells

- Mitosis  one mother cell divides into 2 identical daughter cells with 46

chromosomes (diploid #)

- Meiosis  4 haploid (23 chromosomes) daughter cells which are all different to each

other as well as the diploid parent cell

- The haploid number of 23 chromosomes is important because sperm with 23

chromosomes will fertilise an ovum with 23 chromosomes and this restores our

normal diploid number  if the cells don’t undertake meiosis, we would have double

the number of chromosomes than we need, the cell wouldn’t fertilise and develop

into a baby

Cell Division  mitosis vs. meiosis

- Mitosis:

1. Duplicate DNA

2. Undertake cell division

3. At the end of cell division, we have produced two identical daughter cells that

are identical to the parent cells as well

- Meiosis:

1. Chromosome duplication, synthesis and tetrad formation

2. Chromosomes randomly separate in each cell division

3. Cell divides twice

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 9 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Biol week 3 lc cell division, genetics, and inheritance. Reference chapter 3 and 29 of textbook. Dna = deoxyribonucleic acid (in chromosomes in nucleus) genetic code that"s kept in chromosomes in the nucleus in eukaryotic cells (cells like ours) Rna code and insert the amino acid so that we get the correct protein being made. Dna determines inherited characteristics eg: eye colour; controls body shape; regulates metabolism, protein synthesis and enzyme production. Dna encodes information to make proteins: 1 gene 1 messenger rna 1 specific protein made. Two long chains of nucleotides in a double helix structure. Nucleotide contains: pentose (5 carbon sugar) attached to both, phosphate group, nitrogenous base (acgt) a typically binds with t and g typically binds with c. Sugar of one nucleotide binds to the phosphate of another nucleotide sugar- phosphate backbone structure, with bases between the backbone. Primary role of dna: storage and transfer of information essential to synthesis of proteins in body cells.

Related Questions

22. What is probably the single most important distinction between bacteria and eukaryotes?

a. transcription

b. the separation of the cell's genetic material from the surrounding cytoplasm

c. the existence of ribosomes

d. RNA processing in bacteria

e. antibiotics

23. Which one does NOT characterize an open reading frame (ORF)

a. Uses six reading frames during translation

b. Contains a start codon

c. Contains a stop codon

d. Its length is in multiples of 3 nucleotides

e. It should have the number of codons for a protein or on average ~250 codons in length.

24. Nested intronic genes lie within the non-coding intronic region of a larger gene, and occur in the human genome.

a. True

b. False

25. How would you characterize this statement: EF-Tu will hydrolyze GTP only if the codon:anticodon & tRNA:amino acid matchings are correct

a. Transcription; initiation steps

b. Transcription; termination steps

c. Translation: initiation steps

d. Tanslation: elongation steps

e. Spliceosome

26. Regarding the transcription unit architecture of the Escherichia coli genome, which one is FALSE?

a. Each of the 4,661 transcription units comprised an average of 1.1 modular units.

b. 3,010 transcription units (~65%) are monocistronic.

c. 1,652 transcription units (35%) contain more than one ORF (polycistronic)

d. The largest transcription unit is equivalent to 16 ORFs with numerous introns.

e. 398 transcription units (~9%) are nested within each other in opposite transcriptional orientation

27. Regarding RNA interference (RNAi), which one is FALSE?

a. It is a common and conserved mechanism in eukaryotic cells.

b. Originally discovered in bacteria and plant viruses.

c. A form of primitive immunity to protect the genome.

d. Pre microRNA (miRNA) genes have been found in introns.

e. Recent research shows that exogenous plant miRNAs in food can regulate the expression of target genes in mammals.

28. Aminoacyl-tRNA synthetases

a. Recognize the 3âUTR

b. The genes for these enzymes fall into the family of inducible genes

c. The enzymes are imported into the nucleus

d. Covalently attaches an amino acid to the appropriate tRNA. This takes place in the cytoplasm.

e. Forms the peptide bond during protein synthesis

29. What is the process by which complementary RNAs are made from a DNA template?

a. translation

b. transcription

c. protein synthesis

d. transduction

e. transliteration

cyanbee225

Question 1

The process by which RNA is synthesized using DNA as a template is â¦

Select one:

a. replication

b. transcription

c. translation

d. inspiration

Question 2

Which of the following occurs during meiosis but not mitosis?

Select one:

a. DNA condenses into chromosomes

b. nuclear envelop disappears

c. homologous chromosomes separate

d. sister chromatids separate

Question 3

Which part of the animal life cycle is haploid?

Select one:

a. gamete

b. zygote

c. sporophyte

d. spore

Question 4

Single celled eukaryotic organisms are â¦

Select one:

a. viruses

b. bacterial

c. archaea

d. protists

Question 5

Which type of cellular division results in the formation of diploid cells from a diploid parent cell?

Select one:

a. mitosis

b. meiosis

c. interphase

d. A and B but not C

e. all of the above

Question 6

A sequence of DNA that codes for a single protein is a â¦

Select one:

a. gene

b. ribosome

c. mRNA

d. none of the above

Question 7

Which of the following is characteristic of animals?

Select one:

a. heterotrophic

b. sexual reproduction

c. embryonic development

d. all of the above

Question 8

All genes have only two possible alleles.

Select one:

True

False

Question 9

The presence of membrane-bound organelles is characteristic of â¦

Select one:

a. prokaryotes

b. viruses

c. bacteria

d. eukaryotes

Question 10

What are the building blocks of proteins?

Select one:

a. fatty acids

b. amino acids

c. nucleic acids

d. all of the above

Question 11

During which phase of the cell cycle does DNA replication occur?

Select one:

a. Mitosis

b. Interphase

c. Meiosis

d. Replicosis

Question 12

Which of the following characteristic is shared among fungi and animals?

Select one:

a. autotrophic

b. heterotrophic

c. cell walls

d. absorb nutrients

Question 13

A error in DNA replication that goes unrepaired is a â¦

Select one:

a. chromosome

b. chromatid

c. mutation

d. none of the above

Question 14

Alternate forms of a gene are called ________.

Select one:

a. chromatids

b. chromosomes

c. ribosomal subunits

d. alleles

Question 15

The physical expression of a genotype is the phenotype.

Select one:

True

False

Question 16

In complete dominance, a heterozygous genotype results in â¦

Select one:

a. a recessive phenotype

b. a dominant phenotype

c. a third and unique phenotype

d. none of the above

Question 17

Which theory explains the evolution of eukaryotes from prokaryotes?

Select one:

a. phagocytosis

b. endosymbiosis

c. pinocytosis

d. none of the above

Question 18

Which scientist experimented with plants to describe patterns of inheritance?

Select one:

a. Mendel

b. Chase

c. Einstein

d. Watson

Question 19

Which cellular organelle contains aerobic cellular respiration?

Select one:

a. chloroplasts

b. mitochondria

c. nucleus

d. lysosome

Question 20

Which of the following statements is false?

Select one:

a. Haploid gametes are formed by meiosis

b. Mitosis forms genetically identical daughter cells

c. Mitosis results in the formation of four daughter cells from a single parent cell

d. Mitosis forms diploid daughter cells from a diploid parent cell

Question 21

The first forms of life on Earth were ________.

Select one:

a. plants

b. microorganisms

c. birds

d. dinosaurs

Question 22

Which of the following is used to separate chromosomes during nuclear division?

Select one:

a. cytoskeleton

b. microtubules

c. actin and myosin

d. amoeboid movement

e. all of the above

Question 23

Which generation is most dominant in more primitive plants?

Select one:

a. bryophyte

b. sporophyte

c. gametophyte

d. androphyte

Question 24

Which of the following is characteristic of plants?

Select one:

a. autotrophic

b. contain chloroplasts

c. multicellular

d. all of the above

Question 25

During which phase of mitosis do chromosome line up along the middle of the cell?

Select one:

a. prophase

b. metaphase

c. anaphase

d. telophase

Question 26

During which phase of mitosis does DNA condense into distinct chromosomes?

Select one:

a. prophase

b. metaphase

c. anaphase

d. telophase

Question 27

The process by which DNA is used as a template to make new DNA is â¦

Select one:

a. translation

b. replication

c. transcription

d. allocation

Question 28

Which of the following is characteristic of plant but not animal cells?

Select one:

a. chloroplasts

b. water vacuole

c. cell wall

d. all of the above

Question 29

Which meiotic division is most like mitosis?

Select one:

a. Meiosis I

b. Meiosis II

c. Meiosis III

d. Meiosis IV

Question 30

Which enzyme catalyzes replication?

Select one:

a. DNA polymerase

b. RNA polymerase

c. Ribosome

d. all of the above

Messenger RNA (mRNA)...

a) Is a structural part of a ribosome

b) Brings amino acids to DNA

c) Carries genetic information from the nucleus to the cytoplasm

d) Is a structural part of a chromosome

e) Initiates and directs chemical reactions

Mr. Potato is homozygous dominant (KK), his son, Potato Jr. is heterozygous (Kk). Based on this information, what are the possible genotypes for Mrs. Potato? (Hint: use a Punnet Square).

a) Her genotype is definitely kk

b) Her genotype is either Kk or kk

c) Her genotype is either KK or Kk

d) Her genotype is either KK, or Kk, or kk

e) Mr. Potato cannot be Potato Jrâs biological father

12. Homologous chromosomes:

a) Are members of different chromosome pairs

b) Are genetically identical

c) Carry genetic information that influences the same traits (same genes but probably different alleles)

d) Are only inherited from the mother

e) Are only inherited from the father.

âFitnessâ in an evolutionary sense, refers to an individualâs:

a) Strength

b) Reproductive success

c) Aggressiveness

d) Size

e) Age at death

The fact that individuals who possess favorable traits are more likely to survive and reproduce than those who possess less favorable traits is the basis for the theory of...

a) uniformitarianism.

b) natural selection.

c) the inheritance of acquired characteristics.

d) catastrophism.

e) the fixity of species.

Even with strong selection, genetic variation of a population can be maintained because:

a) Selection only affects one gene at a time.

b) The effects of many alleles are hidden from selection by the effects of other alleles

c) Mutation constantly adds new alleles at an extremely fast rate.

d) Populations always go extinct before their gene frequencies are dramatically altered.

e) Only a and c

Gene Flow is defined as the:
a) Production of new alleles
b) New musical group in which Adam Levine will be the leading vocalist
c) Exchange of genes between populations
d) differential reproductive success of individuals
e) Process by which a DNA base gets extracted out of the nucleus to initiate the process of protein synthesis.

The basic unit of DNA is a molecule called a: a) Nucleotide

b) Base
c) Thymine
d) Prokaryoticcell e) mRNA

How many bases code for one amino acid? a) one

b) two
c) it depends on what amino acid it is d) three
e) four

Hemophilia is a condition that affects: a) more females than males
b) more males than females
c) females and males equally

d) only children born prematurely
e) individuals with a missing portion of chromosome number 5

A clear example of directional selection is:
a) Darwin finches with deeper and thicker beaks associated to a severe drought b) Sickle cell anemia in regions in which Malaria is endemic
c) Achondroplasticdwarfism
d) Fly halteres becoming fully developed wings after modification of a hox gene e) all of the above

Meiosis is evolutionarily significant because:
a) New combination of alleles can arise through independent assortment and crossing over

22.

23.

24.

25.

26.

b) It is the mechanism by which body tissues are repaired
c) It creates somatic cells that are crucial for our body organs to maintain us alive d) It allows forensics to determine the cause of death of unidentified people
e) none of the above

Homologous chromosomes:

a) Are exact copies of each other and contain exactly the same genetic material
b) Are members of different chromosome pairs
c) Are only inherited from the father
d) carry genetic information that influences the same traits (the same genes), however, each of the homologous chromosomes can contain different versions of the same gene (different alleles).

e) carry genetic information that influences different traits because each of the homologous chromosomes contains completely different genes at very different loci

How many chromosome pairs occur in a normal human somatic cell?

a) 46 b) 23 c) 22 d) 24 e) 45

What is the scientific method? Use bullet points to describe the 4 major components.

How is a hypothesis different from a theory?

List the four major components (described during class) necessary for natural selection to occur [AKA Darwinâs Four Postulates] (PDF1-3).

27. Who was Thomas Malthus? In what way(s) Malthus was influential for Darwinâs Theory of Natural Selection? Hint: populations vs resources.

29. What amino acids are being coded for by the gene segment provided below? Nucleotide triplets and their corresponding amino acids are:
ACA= Cysteine; AAA=Phenylalanine; TGG=Threonine; CCT=Glycine; GAT=Leucine; ATA=Tyrosine; AGG=Serine; TCT=Arginine

a) Threonine, serine, glycine, tyrosine, leucine, phenylalanine, arginine, cysteine.

b) Tyrosine, leucine, glycine, threonine, arginine, threonine, serine, cysteine.

c) Arginine, cysteine, serine, glycine, threonine, leucine, phenylalanine, tyrosine.

d) Phenylalanine, leucine, tyrosine, glycine, serine, threonine, cysteine, arginine.

e) Phenylalanine, leucine, tyrosine, glycine, threonine, phenylalanine, arginine, serine.

BIOL125 Lecture Notes - Lecture 3: Haemophilia, Hemoglobin A, Y Chromosome

Document Summary

Get access

Related Documents

BIOL125 Lecture Notes - Lecture 7: Down Syndrome, Egg Cell, Somatic Cell

BIOL 1001 Chapter : Chapter 12 Gene Expression

BIOL 1001 Chapter : Chapter 12 Gene Expression

Related Questions