CHEM/BIO exam 2

Homologous chromosomes

Chromosome pairs with same genes at same loci.

Gene

DNA segment coding for a specific trait

Allele

Alternative forms of a gene (A or a).

Dominant

Trait is expressed with only one copy of allele present

Recessive

Trait is expressed only is 2 copies of the allele present

Homozygous

Two identical alleles (AA or aa)

Heterozygous

Two different alleles (Aa)

Genotype

genes of particular individual

Phenotype

Physical characteristics of the individual or metabolic trait (e.g., brown eyes)

Law of Segregation

Alleles separate during gamete formation in meiosis.

Law of Independent Assortment

Genes for different traits separate independently.

Incomplete dominance

Heterozygous phenotype is between the two parental phenotypes (pink flowers).

Codominance

Both alleles expressed (AB blood type).

Multiple alleles

More than two forms (A, B, O blood types).

Polygenic traits

Many genes affect one trait (skin color, height).

Environmental influence

Environment can alter expression.

Monohybrid

A cross between 2 organisms involving one trait

Dihybrid

cross involving two traits

Autosomal Dominant with example

requires the inheritance of one dominant allele to display disorder (e.g. Huntington's)

Autosomal Recessive

requires inheritance of two recessive alleles to display the disorder (e.g. Cystic fibrosis)

Sex-linked Recessive

mutation in X chromosome

(e.g. hemophilia and color blindness)

Epigenetics

Gene expression changes without DNA change

Twins

Used to study genetics vs. environment

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

Deletion

missing piece

Duplication

extra copy

Translocation

swapped pieces between chromosomes

Inversion

flipped segment

Axial

skull, vertebral column, ribs.

Appendicular

limbs, girdles.

Voluntary muscle contraction

when you make a conscious effort to contract your muscle for a part of your body to move

Involuntary muscle contraction

the part of the nervous system that controls contraction

Stomach

churns food; secretes acid & enzymes.

Small intestine

digestion + absorption

Duodenum

connects to liver, gallbladder, pancreas.

Large intestine

absorbs water; forms feces.

Liver

detoxifies blood, produces bile.

Gallbladder

stores bile.

Pancreas

produce enzymes & hormones

Nutrition

Carbs, proteins, fats, vitamins, minerals, water

Digestive System Disorders

Ulcers, polyps, diarrhea, constipation, pancreatitis, pancreatic cancer, jaundice, hepatitis, cirrhosis, gallstones

Ulcers

Open sores in the lining of the digestive system

polyps

small growths arising from the epithelial lining in the colon

diarrhea

frequent passage of loose, watery stools, can be acute or chronic

constipation

the passage of a hard, dry stool

pancreatitis

inflammation of the pancreas

pancreatic cancer

Cancerous tumor of the pancreas

jaundice

abnormally large amount of bilirubin in blood

hepatitis

inflammation of the liver

Cirrhosis

Chronic disease of the liver

Gallstones

Small crystals that form from bile in the gallbladder.

Heart has 4 chambers:

right/left atria & ventricles

Valves…

prevent backflow

Major vessels

aorta, vena cava, pulmonary arteries/veins.

Pulmonary circuit

heart → lungs → heart

Systemic circuit

heart → body → heart

Blood clotting

platelets + fibrin

Blood pressure

force of blood on artery walls

Disorders of blood

atherosclerosis, hypertension, anemia

Human Genome Project (HGP) goal

to sequence the 3.2 billion bases of the human genome

Key scientists in HGP

Francis Collins (public), Craig Venter (private)

Outcome of HGP

accomplished the goal of sequencing the genome ( sequence did not include centromere or telomere regions)

GINA (2008)

Law preventing genetic discrimination

Genetic Testing reasons

Diagnose disease, ancestry, drug response.

Companies for genetic testing

23andMe (Anne Wojcicki), DNAfit, prenetics, circleDNA, teloyears

Genotyping

determine which genetic variants an individual possesses

Sequencing

determine the exact sequence of a certain length of DNA

SNPs (Single Nucleotide Polymorphisms)

One-base variations that can affect traits/disease risk.

Precision Medicine success

Tailoring treatment to genetics (e.g., cancer therapy).

Precision Medicine barriers

cost, privacy, data analysis

HMP

Human Microbiome Project studied microorganisms in the body

Microbiome findings

gut bacteria affect digestion, immunity, mood

STRs (short tandem repeats) used in

forensics/paternity testing

SNPs used in

ancestry & health prediction.

Public databases

helped solve cold cases (e.g., Golden State Killer)

Parabon Snapshot

predicts facial features from DNA

Face of litter

where genetic material left on litter is used to predict facial traits and generate a sketch of a person's face

DNA fingerprinting

analysis of fragments of DNA as a form of identification

Paternity Testing

Determining biological relationships using DNA.