Bio Sem 2 Unit 2 Exam Rev Flashcards

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1
Q

The structure of DNA

A

Phosphate group
Deoxyribose sugar
Nitrogenous Bases - Guanine, Cytosine, Thymine, Adenine

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2
Q

Name the 3 distinct chemical components in the nucleotide

A

A sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base.

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3
Q

Understand the difference between DNA and RNA

A

DNA has a deoxyribose sugar while RNA has a Ribose sugar

DNA is a double helix while RNA is a single-strand

DNA has Thymine while RNA has Uracil

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4
Q

The general steps to produce a protein from DNA

A
  1. Transcription - DNA is read and transcribed by the RNA polymerase into a single-strand RNA with Thymine being changed to uracil, producing pre-mRNA
  2. RNA editing - Introns are removed, Exons are spliced together - produces mRNA
  3. Translation - The mRNA is translated by the tRNA into a polypeptide protein chain
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5
Q

What is the DNA and RNA base pairing rules

A

DNA
Adenine = Thymine
Guanine = Cytosine

RNA
Adenine = Uracil
Guanine = Cytosine

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6
Q

If DNA sequence is:
ACCAAACCGAGT

Find out the mRNA sequence

A

UGGUUUGGCUCA

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7
Q

What are the functions of
rRNA, mRNA, tRNA

A

rRNA - Makes up 60% of the ribosome; site of protein synthesis

mRNA - Carries the code from DNA that specifies amino acids used in translations (mesenger RNA)

tRNA - Carries a specific amino acid to ribosome, based on its anticodon to mRNA codon

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8
Q

Define Transcription, where and how does it occure?

A

Transcription is the process in which DNA is transcribed into a single strand pre - mRNA

All this happens in the nucleus of a cell

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9
Q

Define RNA processing, where and how does it occure

A

RNA processing or RNA editing is when the RNA polymerase takes in the pre-mRNA and removes the introns and splices together the exons to create a mature mRNA.

This happens in the nucleus of a cell - Transcription

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10
Q

How does nucleic acids encode the instructions to make proteins

A

The mRNA sequence used as a template to assemble the chain of amino acids that form a protein

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11
Q

What is the difference between a triplet, codon, and anticodon?

A

Anticodon - A section of 3 bases that are from the tRNA

Codon - A section of 3 bases that are from the mRNA

Triplet - A section of 3 bases

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12
Q

Define Gene structures
- Exons
- Introns
- Promoter
- Operator regions

A

Exons - Parts of the pre-mRNA that is kept and spliced together to form the mature mRNA

Introns - Parts of the pre-mRNA that is removed (unecessary)

Promoter - section of DNA where RNA polymerase binds and transcription begins

Operator - section of DNA where proteins that control transcription bind

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13
Q

Describe the benefits of gene regulation e.g lac operon

A

Allows cells to react quickly to changes in their environments.

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14
Q

What are the components of a protein

A
  • polypeptide chain of amino acid monomers
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15
Q

Explain the connection between DNA, Genes, Chromosomes and Alleles

A

Chromosomes are a threadlike structure of nucleic acids and protein, carrying genetic information (DNA) in the form of genes

Gene is a section of DNA that carries the code to make a protein - determines the trait

Alleles are alternative forms of gene

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16
Q

Define homologous chromosome

A

Pairs of chromosomes that have same genes and chromosome size

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17
Q

Define Sister chromatid

A

Identical copies of a chromatid that are held together by centromere

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18
Q

Define Centromere

A

The middle of the Chromosome that holds the chromatids together

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19
Q

Define Locus

A

The location of one gene on a chromosome
Loci - multiplie genes on a chromosome

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20
Q

The difference between genes, alleles and genomes?

A

Genome is all of the DNA in an organism, gene is a section of DNA, Alleles are different forms of genes

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21
Q

Difference between autosomes and sex chromosomes

A

Autosomes are chromosomes that determine the traits of an organism while sex chromosome determines the gender of an organism

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22
Q

How do we read a Karyotype

A

First 22 sets of chromosomes are autosomes
Last set (23rd) is sex chromosome

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23
Q

Describe the 5 main types of asexual reproduction

A
  1. Binary fission - bacteria cells - splits from 1 cell to 2 cells once
  2. Budding - Small bud grows out of parent, Two different sized structures made with identical DNA, Bud can breaks off and grow into new organism
  3. Fragmentation - A piece of an organism breaks off and forms an individual organism containing the same DNA
  4. Vegetative propagation - occurs in plants, in which a new plant grows from a fragment or cutting of the parent plant
  5. Sporogenesis (Spore Formation) - The process of formation of spores - has same DNA as parent spores
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24
Q

List 3 Advantages and Disadvantages of asexual reproduction

A

Advantages of asexual reproduction
- Increased speed in population growth

  • offsprings are identical therefore fine-tuned to it’s environment
  • Does not require much energy due to not needing to find a mate

Disadvantages of asexual reproduction
- Lacks the ability to adapt to new environment

  • Disease may affect all the individuals in a population.
  • The organisms produced have shorter lifespans.
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25
Q

Define sexual reproduction

A

Involves the fusion (fertilisation) of two haploid gametes to form a single, genetically unique diploid cell, zygote.

26
Q

List 3 Advantages and Disadvantages of sexual reproduction

A

Advantages of Sexual reproduction
- Increase genetic diversity

  • Improve disease resistance by promoting the presence of different alleles
  • Combining the genetic material from two gametes reduces the chances of an offspring inheriting a genetic disorder that might be carried by one parent.

Disadvantages of Sexual reproduction
- The time, energy, and resources it takes to attract and find a mate

  • Risk of transferable diseases associated with sexual intercourse
  • The risk of losing offspring to outside influences such as embryo damage.
27
Q

Define diploid, haploid, gametes and somatic cells

A
  • Diploid - A cell that contain two sets of each chromosome
  • Haploid - The presence of a single set of chromosomes in an organism’s cells
  • Gametes - Sex cells e.g: sperm and egg

Somatic cells - Normal body cells

28
Q

List and describe the process of reproductive cloning techniques (Embryo splitting and Somatic cell nuclear transfer [SCNT])

A

SCNT
1. Somatic cell from one animal is taken out as well as 1 egg cell from a egg cell donor

  1. Enucleation removes the nucleus from the egg cell to prevent it’s DNA from contaminating the DNA from the somatic cell. At the same time the nucleus from the somatic cell is removed
  2. The nucleus from the somatic cell is than injected into the egg cell which has no nucleus (done w electricity)
  3. The new fused egg cell with the nucleus is than placed into a surrogate mother

Embryo splitting
1. An embryo is split into two at an early stage (6-8 cells)
to develop twins.

  1. Each individual develops as an independent embryo
    and develop into genetically identical offspring.

Artificial embryo splitting
Done artificially, the split embryos are implanted into surrogate mothers until birth.

28
Q

Stages of meiosis

A

Prophase 1 - Chromosome condenses, breakdown of nuclear envelope, crossing over occurs

Metaphase 1 - Homologous chromosome lines up at equator

Anaphase 1 - homologous chromosome move to opposite poles

Telophase 1 & cytokinesis - Chromosomes gather at poles of each cell and cytoplasm divides

Prophase 2 - New spindle fibers form around chromosomes

Metaphase 2 - Chromosomes line up at equator

Anaphase 2 - Centromeres divide, chromatids move to opposite poles

Telophase 2 & cytokinesis - Nuclear envelop forms around chromosomes, cytoplasm divides

29
Q

Define Crossing over

A

Homologous pairs of chromosomes come together before meiosis begins

The chromosomes match up with their homologous pair, and swap sections of their chromosomes.

Leading to genetic diversity by mixing up the genes

30
Q

Define independent assortment

A

The homologous pairs of chromosomes line up in random orientations at the middle of the cell as they prepare to separate leading to genetic diversity by mixing up the genes

31
Q

Describe the importance of genetic diversity in a population

A

Genetic diversity is needed in a population as it increases the Gene pool of different traits therefore leads to certain groups of traits being more favourable than others

32
Q

Difference between meiosis and mitosis

A

Mitosis only splits once while meiosis splits twice

meiosis is usually in sexual reproduction while mitosis is in asexual reproduction.

33
Q

Difference between genotype and phenotype

A

Genotype is the genetic make-up of a person while phenotype is the visible trait presented through features

34
Q

Difference in codominance and incomplete dominance

A

Codominance - Mix of genes and visual features of both parents

Incomplete dominance - A blend of genes and visual features of both parents

35
Q

Pattern of inheritance
Autosomal
Sex-linked
Dominant
Recessive

A

Autosomal - affects both male and female equally
Sex-linked - Affects mostly females
Dominant - is seen in all offsprings
Recessive - Comes and goes from generation to generation (usually re-appears in the third generation)

36
Q

Define consequence based approach

A

Maximise positive outcomes while minimising negative effects

37
Q

Define rules based approach

A

Follow set rules and responsibilities, with less regards for the consequences that may result

38
Q

Define virtues based approach

A

Emphasise the moral nature of the individual, and provide guidance as to the behaviours a morally good person would hope to achieve

39
Q

Define integrity

A

Trustworthy and Honesty

40
Q

Define respect

A

Acknowledgment of the intrinsic value of living things, and considers the welfare, beliefs, customs, and cultural heritage of both the individual and the collective

41
Q

Define justice

A

Fair consideration of competing claims, and ensures that there is no unfair burden on a particular group from an action

42
Q

Define beneficence

A

Maximise benefits when taking a particular position or course of action

43
Q

Define non-maleficence

A

Discourages causing harm – or when harm is unavoidable ensuring positives outweigh the negatives

44
Q

Define antigen

A

Any molecule that can produce an immune response

45
Q

Define self antigen

A

Surface molecules that that identify them as self.
Major histocompatibility complex (MHC) proteins.

46
Q

Define non-self antigen

A

Antigens that originate from outside the host’s body.

47
Q

Define allergen

A

When the immune system reacts incorrectly to a molecule that is not a pathogen

48
Q

What is the importance of self and non-self antigens in immune function?

A

Self antigens allow for recognition of own body cells

Non-self antigens allow for recognition of foreign cell and elimination of foreign cell

49
Q

General features of the six different types of pathogens

A

Parasites - largest pathogen - worm-like

Protozoa - cell pathogen

Fungi - groups of single cells

Bacteria - Cell with cell membrane and wall as well as a flagella - reproduces through binary fission

Viruses - non-living, only has cell wall and RNA

Prions - misshaped proteins that causes other proteins to misshape (smallest pathogen)

50
Q

Difference between cellular and non-cellular pathogens

A

Cellular pathogen- living, has membrane bound organelles and can reproduce by itself
Non-cellular - non-living, has no membrane bound organelles or no organelles at all, can not reproduce by itself

51
Q

Difference between first, second and third lines of defence

A

First - Innate immunity
- Barriers to prevent pathogens from entering (skin, mucous membrane)

Second - Innate immunity
- Mostly involves immune cells and proteins to nonspecifically recognize and eliminate any pathogen that enters the body (Phagocytes, antimicrobial proteins , inflammatory response, Fever)

Third - Adaptive immunity
- adaptive immune system develops as we encounter antigens throughout our lives, adaptive immune system is slower to activate (days) (Lymphocytes, antibodies, memory cells)

52
Q

Define chemical, physical and microbiological barriers
- give examples in humans

A

Chemical - Barriers with chemical substances that make the environment hard to live in for pathogens - Stomach acid, enzymes in saliva, antibacterial proteins

Physical - Barriers that block or hinder pathogens from entering an organism - Skin, mucus secretions

Microbiological - Non- pathogenic bacteria (flora) prevents the growth of other bacteria due to competition - bacteria on skin and in lower intestines, non-pathogenic organisms in the vagina

53
Q

Define phagocytes

A

cells that do phagocytosis, a process in which they consume and destroy pathogens and foreign material. This is a process of the innate immune system.

54
Q

3 types of phagocytes

A
  • neutrophils
  • macrophages
  • dendritic cells
55
Q

Describe the steps of the inflammatory response

A
  1. Damaged tissues attract mast cells which release histamines which defuses in the blood vessels
  2. Histamine dilutes blood vessels and becomes leaky, complement proteins leave vessels and attract phagocytes
  3. Blood plasma and phagocytes move into infected tissue from the vessels
  4. Phagocytes engulf bacteria and dead cells
  5. Histamine and complement signaling cease, phagocytes no longer attracted
  6. Wound heals from white blood cells and platelets producing growth factors
56
Q

3 main functions of complement proteins

A

Membrane attack - rupture of the cell wall of bacteria

Phagocytosis - enhance phagocytosis

Inflammation - by attracting macrophages and neutrophils

57
Q

What are the key similarities and differences between the humoral and cell mediated pathways of adaptive immunity

A

Differences - Humoral immunity produces antigen-specific antibodies, whereas cell-mediated immunity does not

Similarities - Both humoral and cell-mediated immunity are active immunities

58
Q

Be able to draw a diagram of an antibody, label its antigen-binding site

A
59
Q

Describe how vaccination works

A

Vaccination works by providing a dead or weakened version of a pathogen which triggers the immune system, this immune response allows the body to remember the pathogen in cause in the future the real pathogen comes to invade the body

60
Q

Define and identify dependent, independent and controlled variables

A

Independent variable - A variable that you can manipulate

Dependent variable - A variable that is changes due to the independent variable

Controlled variable - A variable that is set by you and does not change / can not be manipulated

61
Q

Define and identify experimental control or control group

A

allow the experimenter to minimize the effects of factors other than the one being tested.