Class notes
terminology life sciences/bio notes
- Course
- Life Sciences
- Institution
- 12th Grade
My notes are concise and to the point, making them ideal for quick review sessions before exams or quizzes.
[Show more]
Seller
Follow
Content preview
Biology TerminologyDNA
DNA - Made up of 2 strands/nucleic acids wrapped around to form a double Helix.
Nucleotide – The building block of nucleic acids. Consists of: Phosphate, Deoxyribose sugar &
Nitrogenous base.
Nitrogenous base – Have complementary pairs.
– Purine bases: Have 2 Carbon rings (BIG) -> A & G
– Pyrimidine bases: Have 1 Carbon ring (SMALL) -> T & C
– Names of Nitrogenous bases: Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Uracil (U)
RNA
– Shorter than DNA
– Single stranded
– Contains Ribose sugar instead of Deoxyribose sugar.
mRNA – Messenger RNA
– Carries the instructions from DNA about which amino acids will be in a polypeptide.
tRNA – Transfer RNA
– Transports amino acids to the ribosome to create an amino acid chain.
Protein Synthesis – Process of making proteins in a cell.
Transcription – Occurs in the nucleus.
– Where DNA is being converted into mRNA.
Translation – mRNA strand is translated into a string of amino acids.
Codon – A triplet of nitrogenous bases on a piece of mRNA that codes for a particular amino
acid.
Anti-Codon – Sequence of 3 nucleotides forming a unit of genetic code in a tRNA molecule,
corresponding to the complementary codon in mRNA.
Amino acids – Monomer of proteins.
mtDNA – Mitochondrial DNA. Passed down from one’s mother only, found in the
mitochondria.
Gene – Sequence of nucleotides on a chromosome that codes for a particular trait/protein.
DNA Replication – Process which produces an exact copy of a DNA molecule (i.e. replicates).
– Occurs during interphase. – Occurs only in the nucleus.
– Purpose is to prepare cell for mitosis or meiosis.
DNA profiling – Purpose: -> To identify samples (blood, semen, skin cells, root hair – must
have a nucleus).
-> Forensics/solving crimes, paternity test, missing ppl, certain genetic diseases.
, – Steps: -> PCR (Polymerase Chain Reaction): Used to amplify (make more of) the DNA.
-> Restriction enzymes: Cut DNA into fragments.
-> Gel electrophoresis: - Separates out the bands so that DNA fingerprints can be compared.
- DNA bands separated according to size, using electric current.
Non-coding DNA – Sequence of nucleotides on a chromosome that DOES NOT code for a
particular trait. Used in DNA fingerprinting.
MEIOSIS
Meiosis – Meiosis is a form of cell division whereby haploid gametes are formed that are
genetically non-identical.
Homologous pair – Paired chromosomes that are the same size, same shape & same gene at
the same locus.
Haploid (n) – Half complement of chromosomes.
Diploid (2n) – Full complement of chromosomes.
Reduction division – Number of chromosomes formed halved.
Gametes – Sex cells.
Crossing over – Results in recombination of alleles for variation. Occurs in Prophase 1.
Random assortment – When chromosomes (OR replicated chromosomes) line up at equator
in no particular order. (Occurs in either Metaphase 1 or Metaphase 2)
Chiasma/Chiasmata – Point where chromatids cross.
Non-disjunction – Failure of chromosomes to separate during Anaphase 1 or Anaphase 2.
Karyotype – Picture of chromosome.
Aneuploidy – Occurs when there is 1 extra (trisomy) or 1 missing (monosomy) chromosome.
Polyploidy – Occurs when there is many extra SETS of chromosomes.
GENETICS
Gene – Sequence of nucleotides on a chromosome that codes for a particular trait/protein.
E.g., eye colour.
allele – Alternate form/Variation of the gene. E.g., blue, brown, green, hazel.
locus – Position or location of the gene on the chromosome.
Heterozygous – When a person inherits different alleles for a gene pair. E.g., Rr, Bb, Tt.
Homozygous dominant: When a person inherits both dominant alleles for a gene pair. E.g.,
RR, BB, TT.
Homozygous recessive – When a person inherits both of the (same) recessive alleles for a
gene pair. e.g., rr, bb, tt.
Dominant – The trait that is expressed when in a heterozygous condition.
Recessive – The trait that will only be expressed if a person inherits both alleles.
Phenotype – Physical makeup of the individual.
P1 – First generation of parents.
Genotype: Genetic makeup of individual for that gene.
Genome – Complete set of genes of a particular organism.
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 EFT, 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 this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller kgotsotlake4. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R109,33. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
56326 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now