T3: Voice Of The Genome Flashcards
Name 2 types of organism
Eukaryote/prokaryote
Give 4 examples of eukaryotes
Animals
Plants
Fungi
Protocists
Describe characteristics of eukaryotes (4)
Contain membrane bound organelles
Normally larger than prokaryotes
Usually multicellular
Compartmentalisation
Name 10 organelles of a eukaryote cell
Right endoplasmic reticulu,
Centrioles
Lysosomes
Golgi apparatus
Smooth endoplasmic reticulum
Ribosomes
Cell memebrane
Mitochondria
Nucleolus
Nucleus
Rough endoplasmic reticulum
Double membrane layer
Embedded ribosomes
Protein synthesis/translation
Centrioles
2 hollow microtubule cylinders
Help organise spindle fibres
Lysosomes
Single membrane bound vesicle
Digestive enzyme
Golgi apparatus
Stack of flattened vesicles
Modifies proteins (adds sugars)
Smooth endoplasmic reticulum
Lipid synthesis
Ribosomes
No membranes
Mitochondria
Own circular chromosome
Double membrane
Inner membrane folded into cristae, higher SA
Nucleolus
No membrane
Active rRNA transcription area
Nucelus
Contains DNA
Double membrane (nuclear envelope)
Pores, RNA —> cytoplasm
Eukaryote cell radius
10 micrometers
Prokaryote example
Bacteria
Prokaryote characteristics
Don’t have membrane bound organelles
Normally smaller than prokaryote
Unicellular
Name 10 prokaryote organelles and whether they are always or sometimes present
Cell membrane
Cell wall
Circular DNA chromosome
Ribosomes
Cytoplasm
Mesosome
Slime capsule
Plasmids
Flagella
Pili
Mesosome
Increase respiration SA
Pili
Attachment
Conjugation
- asexual report ion via binary fusion
- sexual reproduction via conjugation
Protein trafficking process
DNA -> RNA (transcription)
mRNA nucleus —> nuclear envelope –> ribosome
Ribosome makes protein (translation)
Protein —> rER —> tertiary structure
Vesicles pinched off rER (contains protein)
Vesicles —> flattened Golgi app sacs
Proteins modified in Golgi app
Vesicles pinched of Golgi app (contains modified protein)
Vesicles fuse to cell surface
Release protein (eg. Extracellular enzymes)
Egg cell features
Cortical granules
Lipid droplets (energy store)
Zona pellucida (jelly coating)
Haploid nucleus
Follicle cells (help ovum develop)
Lysosomes (vesicles, digestive enzymes)
Egg cell diameter
100 ym
Sperm cell head length
5 ym
Sperm cell features
Haploid nucelus
Acrosome (digestive enzymes)
Flagella
Mitochondrion
Fertalisation generally
Gamete fusion
2X haploid —> diploid zygote
Meiosis characteristics
2 round cell div
Makes 4 genetically non-identical gametes
2 ways of genetic variation
- independent assortment (only div round 1)
- crossing over
Independent assortment
Homologous chromosomes (bivalents) associate
Paternal/maternal
Random orientation
No. Chronometer combinations = 2*haploid number
Crossing over
Chiasm
Prophase 1
New allele combinations
Di-hybri inheritance
2 genes
4x4 pundit square
Back cross technique
Cross unknown with double homozygous recessive
Reveals genotype
Ratio of offspring assumes independent assortment
Why are all gametes usually equally likely
Independent assortment
What can be assumed if gamete ratio is significantly different than expected
Genes are linked
Genes have loci on same chromosome
Loci
Position of gene on chromosome
Linkage group
All genes on one chromosome
How can you break linkage between genes and what varies this likelihood
Crossover
Crossover less likely, closer genes are together
Sex linkage
Locus of gene on same sex chromosome
Most sex linked genes on X chromosome, longer than Y, more likely
Hemizygous
One copy of an allele
Stem cells
Undifferentiated
Capacity to keep dividing
Hayflick limit
Theoretical no. Times cell can divide
Name 3 types of stem cell
Totipotent
Pluripotent
Multipotent
Totipotent
Cell can give rise to all cell types
Pluripotent
Cell can give rise to many cell types
Multipotent
Cell can give rise to some cell types
Example use of stem cells
Leukaemia
Bone marrow transplant
Matched donor
Embryonic pluripotent stem cells vs adult multipotent range of possible cells
High, low
Embryonic pluripotent stem cells vs adult multipotent requirement to match
Yes, no
Embryonic pluripotent stem cells vs adult multipotent ethical concerns
High, low
What do all cells except red blood cells contain
Whole genome
Experiment to show un/differentiated cells
mRNA: cDNA hybrid molecules, represent genes on both
cDNA single stranded molecules, represent genes only switched on in differentiated cells
mRNA single stranded molecules, represent genes switched on only in undifferentiated cells
Un/differentiated cells experiment process
Undiff cells frogspawn mRNA extracted
Diff cells mRNA extracted, cDNA made using reverse transcriptase
mRNA digested
cDNA and mRNA combined
Any mRNA also in diff cells will combine with cDNA —> double strand
Free cDNA is from mRNA only in diff cells
2 stages of the cell cycle
Interphase
Mitotic stage
What happens during interphase
Energy store increase
Cell grows in size
Organelles replicated
DNA copied
What happens during mitotic stage
Nuclear division (mitosis)
Cell division (cytokinesis)
Appearance during interphase
Cant see chromosomes
Name of centre of homologous chromosomes
Centromere
Stages of mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Central cell membrane pulle dinwards
Groove made
Membranes fuse to form 2 cells
Ways in which plant cell division differs from animal (3)
Centrioles not involved in spindle fibres, no centrioles in cell
Membrane cant furrow inwards, Golgi apparatus makes vesicles down middle, form membrane
Cellulose cell wall forms down centre
Prophase
Chromosomes visible
Nuceleolus dissapeas
Spindle fibres join centromeres to centrioles
Nuclear membrane breaks down
Metaphase
Chromosomes line up along equator
Spindle fibres attach
Anaphase
Spindle fibres shorten
Pull chromatids towards opposite poles
Telophase
Spindle fibres dissapear
Nuclear membranes reform around 2 separate chromosome groups
Acrosome reaction
Vesicles fuse with sperm membrane
Digestive enzymes released
Zona pellucida broken down
Cortical reaction
Cortical granules fuse with ovum membrane
Enzymes released
Zona pellucida hardens so no mor sperm can enter
Mitotic index
No. Cells in mitosis / total no. Cells x100
Define a cell and give an example (3)
Smallest unit capable of independent life
Bound by a membrane
Contains organelles
Eg. Red blood cell
Define a tissue and give an example (5)
Group of similar cells
Express similar genes
Same function
Cells have memebrane adhesion proteins
Some have cells AND Extracellular matrix
Eg. Muscle tissue
Define a organ and give an example (2)
Group of interconnected tissues
Work together to complete functions
Eg. Liver
Define an organ system and give an example
Group of organs
Work together in coordination
Eg. Circulatory system
What is the Jacob-Monod hypothesis
Genes will be switched on in response to environmental stimulae
Lac Operon
B-galactosidase enzyme, lactose —> glucose
Only produced in presence of lactose
Absent
Repressor molecule —> DNA
Prevent B-galactose gene
RNA polymerase cant bind/transcribe
Present
Repressor molecule prevented from binding
Binds to lactose
Translation of gene
Enzyme made
Discontinuous variation
Characteristics shows one of few discrete possibilities
Eg. Eye colour
Continuous variation
Characteristic shows wide range of possibilities
Controlled by many genes
Mixture of genetic and environmental
Eg. Height
Transcription factors
Important in gene expression
Typically control short term gene activation
Epigenetic changes
Modify chromosome but not DNA base sequence
DNA methylation
Addition of methyl; group to cytosine in CpG position, DNA tightly coiled ad inaccessible, turns off epigenetic change
Histone modification
Addition of acetyl group to histone protein
DNA inaccessible
Turns on epigenetic change
What 2 processes turn epigenetic changes on and off
DNA methylation: off
Histone modification: on
