Bio182 Intro to Genetics - Lecture Notes Review (Vocabulary Flashcards)

Vocabulary flashcards covering key genetics concepts from the lecture notes.

Central Dogma

Flow of genetic information from DNA to RNA to protein. (Transcription from DNA to RNA and Translation from RNA to protein)

DNA

Deoxyribonucleic acid; the macromolecule that stores genetic information in sequence of nucleotides.

RNA

Ribonucleic acid; nucleic acid used in transcription and translation to build proteins.

Genes vs alleles

Gene is a segment of DNA and an alleles is the different type of gene; you inherit two types of alleles, one from mom and dad, and they are on the gene

Genotype

The genetic makeup of an organism; the alleles that are expressed

Phenotype

The observable traits of an organism, influenced by genotype and environment.

Nucleotide

Building block of DNA/RNA; consists of sugar, phosphate, and a base.

Chargaff's Rule

In DNA, %A = %T and %C = %G; base compositions are balanced.

Hydrogen bonds

Weak bonds between complementary bases (A–T = 2, G–C = 3) that hold DNA strands together.

Complementary strands

DNA strands with bases that pair specifically: A with T, G with C.

Sister Chromatids

When a chromosome replicates itself exactly; so usually its just one thread that is a chromosome, but then it replicates with same genes and alleles and it is now an X

Homologous pair

Inherit one chromosome from each parent and same type of chromatids come together; unreplicated just two and if replicated= 4 strands so two X

Transcription

Synthesis of RNA from a DNA template.

Translation

Synthesis of a protein from an mRNA sequence.

Coding strand

DNA strand whose sequence corresponds to the mRNA (T instead of U).

Template strand

DNA strand used by RNA polymerase to synthesize RNA; complementary to mRNA.

RNA polymerase

Enzyme that reads DNA and builds a complementary RNA strand.

Codon

Three-nucleotide sequence in mRNA that encodes an amino acid.

Start codon

AUG; signals the beginning of translation.

Stop codon

UAA, UAG, or UGA; signals termination of translation.

Genetic code

Rules by which codons specify amino acids; largely universal.

Gene

DNA sequence that codes for RNA or a protein.

Allele

Different versions of the same gene.

Homozygous

Having two identical alleles for a gene.

Heterozygous

Having two different alleles for a gene.

Dominant allele

Allele that is expressed when present (one copy in many cases).

Recessive allele

Allele expressed only when two copies are present.

Mutation

A change in the DNA sequence that may alter function.

Frameshift mutation

Insertion or deletion that shifts the reading frame of the gene.

Point mutation

A change in a single nucleotide.

Deletion

Loss of one or more nucleotides from a DNA sequence.

Duplication

Copying of a region of DNA, leading to extra genetic material; developmental issues

SNPs

Single nucleotide polymorphisms; single base changes that vary among individuals.

Sickle cell anemia

Autosomal recessive disorder due to a single nucleotide substitution in HBB gene.

Cystic fibrosis

Autosomal recessive disease caused by mutations in CFTR, leading to thick mucus.

Gene therapy

Treatment that replaces or repairs a mutated allele to restore function and is put into organism to replicate

Wildtype

The typical or normal allele that produces a functional protein.

BRCA2

Tumor suppressor gene on chromosome 13 involved in DNA repair; mutations increase cancer risk.

Chromosome

Thread-like structure of DNA and proteins that carries genes.

Ploidy

Number of chromosome sets in a cell

Ex: humans are diploids because we have 2 copies of chromosomes in each cell

Haploid

One set of chromosomes (n).

What the daughter cells in meiosis are

Diploid

Two sets of chromosomes (2n), as in most human cells.

N

Refers to the number of chromosomes in a single set; how many unique inks of chromosomes there are

Karyotype

Chart of an organism’s chromosomes used to examine number and structure.

HeLa cell

Immortal human cell line derived from cervical cancer used in research.

Sex chromosome

Chromosome involved in determining sex (X and Y in humans).

Y chromosome

Male sex chromosome; carries few genes beyond sex determination.

SRY gene

Sex-determining region on the Y; initiates male development; can be translocated to X.

Sex-linked inheritance

Traits carried on sex chromosomes (X or Y), often exhibiting gender-biased patterns.

Mitochondrial DNA

DNA in mitochondria; inherited maternally and used to trace maternal lineage.

Pedigree analysis

Diagram showing trait inheritance in families to predict patterns.

Autosomal dominant

Dominant allele on a non-sex chromosome; typically appears in every generation.

Autosomal recessive

Recessive allele on a non-sex chromosome; often skips generations.

Huntington's disease

Autosomal dominant neurodegenerative disease.

X-linked inheritance

Traits controlled by genes on the X chromosome; often more severe in males.

Nondisjunction

Failure of chromosome separation during meiosis, causing abnormal chromosome numbers.

Meiosis

Cell division that produces haploid gametes with half the chromosome number; 4 half daughter cells and you see which one the other gamete will latch onto

Prophase 1

Right after Interphase where DNA replication is happening; homologous pairs present so four chromosomes, two replicated pairs one from mom and dad

Metaphase 1

Each homologous pair align next to one another near equator; pairs on either side and law of independent assortment occurs here

Anaphase 1

Members of homologous pairs will be pulled to opposite poles and this is the law of segregation

Telophase 1

Nuclear membrane will divide so that the policy is 1 and N=2; i version of each chromosome and go into meiosis 2

Metaphase 2

After prophase 2 where the chromosome/ sister chromatids are lined at the equator

Anaphase 2

Sister chromatids re pulled apart so that only one chromosome is in each cell so we are now a haploid;

Products= 4 gametes that are not identical nor are they identical to the original cell

It would change end genotypes and all genotypes are equally likely to happen still

Why if we had a different alignment in metaphase 1?

Mitosis

Cell division that creates two genetically identical somatic cells that are diploids

Interphase

Cell cycle phase where growth occurs and DNA is replicated before division; G1, S, G2, G0

G1

Unreplicated chromosome; everything else in teh cell is duplicated except for that

S

Each of 46 chromosomes is duplicated and homologous are present with sister chromatids that are identical

G2

Checks for any errors to see if mitosis can continue;

G0

Cell dies and never replicates

Prophase

Replication and right after G2; policy=2 and N=1

Metaphase

Chromosomes re replicated and line up in the middle so one of each gets pulled into the new cell; policy=2 N=1

Anaphase

Sister chromatids er being torn apart and now they re unreplicated, identical chromosomes on each side

Telophase

Chromatids have moved to opposite sides and waiting for it to be pinched and the new membrane is wrapping around cells with same amount of genetic info in all cells

Gamete

A reproductive cell (sperm or egg) that is haploid.

Zygote

Diploid fertilized egg formed by union of gametes.

Punnett square

Grid used to predict offspring genotypes and phenotypes from parental genotypes.

Independent assortment

Mendelian principle that genes on different chromosomes assort independently during gamete formation.

Locus

Specific location of a gene on a chromosome.

Law of Segregation

During gamete formation, two alleles for a gene separate so each gamete gets one.

Phenotype vs genotype

Genotype is the set of alleles; phenotype is the observable trait resulting from gene expression and environment.

Codominance

Both phenotypes are expressed and there is a new overall phenotype; both alleles are expressed for trait and are equally dominant like AB blood type; red and white flower breed= striped red and white

Incomplete dominance

Part way in between with recessive and dominant gene; make new thing with a mix of the parents so red flower and white flower breed and new flower is pink

Linked traits

Genes are located on same chromosome and inherited together; these do not assortment independently

Polygenic traits

Traits controlled by a bunch of genes with small effects

Pleiotropy

Same gene can have multiple effects in phenotype

Epistais

Gene is affected from what other genes there are

Sex linked traits

When traits are passed down on the sex cells; usually they are associated with males because they are on the X chromosome and males only have one so if it is on there, they have it