Summary
Summary Study Unit 1 Genetics 214
- Course
- Institution
- Book
Mitosis & Meiosis, Mendel’s postulates and the various extensions of these,
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
chellsmit
Content preview
GeneticsStudy of how Biological information is stored, transmitted, translated and expressed ->
heredity & variation.
Chromosomal theory of inheritance: Each trait controlled by pair of factors
Heredity & development dependent on (genes).
genetic info residing in genes, contained in • Diploid number (2n): 2 chromosomes.
chromosomes, faithfully transmitted through • Haploid number (n): 1 chromosome.
gametes. • Homologous chromosomes:
chromosomes exists in pairs.
Alleles: alternative forms of same genes. • Mitosis: chromosomes copied &
Phenotypes: different alleles produce distributed as diploid set to each
differences in observable features.
daughter cell (identical).
Genotype: set of homologous copies of alleles
for given trait.
• Meiosis/gamete formation: daughter
Locus: place on chromosome where particular cell receives 1 chromosome from each
gene located. pair = reduction, 2n -> n (not identical).
Trait: genetically determined characteristic due Reduction essential = maintain
to specific genes a chromosome. constant number of chromosomes.
Autosomal genes: are not located on X or Y
chromosomes (not sex dependent). Genetic variation:
Sex dependent: genes carried on X and Y
chromosomes.
Mutation: any heritable change in DNA
sequence & source of all genetic
variation.
Chemical nature of genes
Genes carried on chromosomes -> proteins & RNA, single stranded molecule, with
DNA major chemical components. Uracil instead of thymine.
DNA
Carrier of ALL genetic information. Macro
molecules made up of sugar (deoxyribose),
phosphate & nucleotides:
Uracil = Pyrimidine (1 ring)
• Guanine:
Central dogma
How genes create proteins.
Transcription: in nucleus, where DNA
constructs complimentary RNA sequence
• Cytosine:
(mRNA). mRNA moves to cytoplasm & binds
to ribosomes.
Translation: on ribosomes, where the
genetic code in mRNA consists of codons (3
linear nucleotides). tRNA recognize info
• Adenine:
encoded in mRNA codon & carry proper
amino acids for construction of proteins.
Proteins
Polymers made of 20 different amino acid
• Thymine: monomers & are end products of gene
expression.
Diverse biological functions due to many
different combinations of 20 amino acids.
DNA twisted into double helix, exact Amount of sequences:
complements to on another: 20 n – amount of amino acids.
Enzymes (largest category) used as catalyst
to lower activation energy to allow cellular
metabolism to proceed at body temp.
Guanine & Adenine = Purines (2 rings) M.Smit 22631585@sun.ac.za
Cytosine & Thymine = Pyrimidines (1 ring)
, Chromosomes
Cell & genetic material: Homologous chromosomes: identical in
Plasma membrane: outer covering defining cell length, genetic loci & centromere placement.
boundaries &controls movement of material. • Sex-chromosomes not homo.
Microtubules: fibers of tubulin (protein) +
microfilaments of actin (protein).
Centrioles: organelle made of microtubules, which
organizes microtubules into spindle fibers.
Spindle fiber: lengthen & shorten as addition/loss of
polarized tubulin subunits.
Centrosome: differentiated cytoplasm containing
centrioles.
Chromatin: network of uncoiled chromosomes &
DNA, RNA, histones and other proteins
Centromere: specialized heterochromatic
chromosomal region where sister chromatids
remain attached after replication & where spindle
fibers attach during mitosis/meiosis.
Karyokinesis: nuclear division.
Cytokinesis: cytoplasmic division.
Sister chromatids: genetically identical
chromatids, of same homologous pair.
Biparental inheritance: each sister chromatid
come from maternal & paternal.
Cell cycle
Interphase – G1, S + G2
• Intensive metabolic activity, cell growth &
M Checkpoint:
cell differentiation are evident.
Chromosome • G2 (gap II) end: volume of cell doubled &
G2 Checkpoint:
spindle attached DNA replicated -> mitosis.
Cell size & if
DNA replicated • G2 & S phases lengths are consistent in
correctly all cell types.
• S phase: cohesion forms between sister
chromatids.
• G1 phase length depends on cell.
• G1 point where:
Cell proliferation occurs – initiating DNA
replication.
No proliferation – entering G0 –
withdrawal from cycle, still metabolic
active.
Cancer cell avoid/fast tracks G0.
G1 Checkpoint:
Enough
resources
M.Smit 22631585@sun.ac.za
(nutrients),
growth factors &
DNA damage
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller chellsmit. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $6.77. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67474 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now