DLISC1 - week 3 Flashcards
(26 cards)
Who deduced the double helix structure and what year?
James Watson and Francis Crick in 1953
Eukaryotic cell division is divided in phases, brifely describe
Interphase = G1, S, G2 (between cell divisions)
M Phase = mitosis and cytokinesis (dividing phases)
genetic shuffling of Meiosis 1
in addition to a new combination of chromosomes resulting from fertilisation, there are also events in Meiosis 1 that shuffle the genes
1. Crossing over in prophase 1
2. Independent assortment in metaphase 1
levels of organism (more complex)
atom
molecule
macromolecule
organelle
cell
tissue
organ
organ system
organism
what is the central dogma?
1958 - crick coined the phrase ‘central dogma’ to refer to the flow of genetic infromation from DNA to protein
what is a genotype?
the specific allele composition of a cell
the complete set of genes inherited by an individual organism
inherited from parents
identical twins share the same genoype
what is a phenotype?
the detectable outward manifestations of a specific genotype
describes all aspects of an indivdual organisms morphology
heritable component, but influenced by the environment
no tow organisms share the same phenotype
what are mutations?
changes in nucleotided sequence of DNA
may occur in somatic cells and gametes
name two genetic disorderes with medilian phenotypes?
hemophilia
muscular dystrophy (duchenne)
describe hemoplilia
symptom: blood fails to clot
defect: defective blood clotting factor VIII
dominant/recessive: x-linked recessive
describe muscular dystrophy (Duchenne)
symptom: muscle waste away
defect: degradation of myelin coating nerves stimulating muscles
dominant/recessive: x-linked recessive
types of mutations
chromosome mutation
gene mutations
chromosome mutations
the mutation of the chromosomal segments of the DNA strands
five types exist: deletion, inversion, duplication, translocation and nondisjunction
gene mutations
refer to base change in the nucelotide sequence of a gene intragentic additions, deletions or rearrangements that disrupt normal gene function
types: point mutations (includes substitutions, insertions and deletions) and frameshift
genetic disorders
many hereditary disorders are caused by recessive, defective alleles
estimated that people carry 3-5 such alleles
each paretns must carry 1 recessive allele. offspring must inherit the defective allele from both paretns and ge thte disease
structure of prokaryotic cell
cytoplasm
plasmid
flagellum
plasma embrane
cell wall
capsule
nucelotide
ribosomes
pili
prokaryotic cells
single-celled organism which lacks a nucleus and other membrane-bound organelles
shape and size can be one of three determined by cell wall: rods, spherical or oval, long and helical
eukaryotic cells
more complex then prokaryotic
DNA housed in nucleus
supported by cytoskeleton internal protein scaffold
structure of eukaryotic cells
peroxisome
mitochondria
vacuole
golgi apparatus
nucleus
ribosomes
cytoplasm
lysosome
cell membrane/plasma membrane
nucleus
cytoskeleton
endoplasmic reticulum
eukaryotic cell division/cycle
- G1 (gap/growth phase 1) - growth and preparation of DNA synthesis
- S (synthesis) - DNA replication
- G2 (gap/growth phase 2) - growth and preparation for mitosis; oprganelles replicate and microtubles form spindle
- mitosis - serperation of replicated chromosomes, subdivided into 5 phases
- cytokenesis - cytoplasm divides leading to seperation of 2 daughter cells
what is mitosis?
division of somatic cells in eukaryotic organisms
a single cell divides into 2 identical daughter cells
daughter cells have same number of chromosomes as does parents cells
5 phases (PMAT)
1. prophase
2. prometaphase
3. metaphase
4. anaphase
5. telophase
what is meiosis?
is a type of cell division that occurs in sexually reproducing organisms, resutling in the formation of four unique daughter cells, each with half the number of chromosomes of the original cell. process is crucial for reproduction as it produces games (sperm and egg cells)
what are the 4 primary tissue types?
epithelial
connective
muscle
nerve
epithelial tissues
can arise form all primary germ layers
function: protection, absorption, secretion and filtration
can be simple (1 layer thick) or stratified (2+ layers thick)
