Chapter 9 Flashcards
What is genetics?
The study of how characteristics are passed from one generation to the next.
Define heredity.
The transmission of characteristics from parent to offspring by means of genes in the chromosomes.
What controls heredity?
Genes or nucleic acids (DNA) in body cells.
What are chromosomes?
Threads of living matter that carry genes.
What are alleles?
Alternative forms of the same gene (dominant versus recessive).
What is a genotype?
The genetic make-up for a single trait of an individual.
What is a phenotype?
A particular trait that is observed in an individual.
What does homozygous mean?
Having two identical alleles for a trait.
What does heterozygous mean?
Having two different alleles for a trait.
What is the difference between carriers and non-carriers?
Carriers have a heterozygous genotype and can pass on abnormal alleles; non-carriers do not.
What are genetic diseases?
Abnormalities caused by inherited recessive alleles, leading to severe structural changes or altered metabolism.
What is natural immunity?
The phenomenon where certain species are resistant to specific diseases.
Define zoonosis.
A disease common to both humans and animals.
What is anthrax?
A bacterial disease caused by Bacillus anthracis, affecting primarily ruminants.
How is anthrax transmitted?
When bacteria spores are ingested or through handling infected animals.
What are the three clinical forms of human anthrax?
- Cutaneous
- Intestinal
- Pulmonary
What is brucellosis?
A disease caused by Brucella organisms, affecting livestock and occasionally humans.
How do humans contract brucellosis?
By exposure to infected animals or ingestion of contaminated foods.
What is the most common zoonotic disease?
Campylobacteriosis, also known as vibriosis.
What is the causative agent of Campylobacteriosis?
Campylobacter jejuni.
What are common symptoms of Campylobacteriosis in humans?
Abdominal discomfort, diarrhea, and fever.
What are the modes of direct disease transmission?
- Skin contact
- Ingestion
- Inhalation
- Venereal methods
What are vectors in disease transmission?
Organisms like flies, mosquitoes, and ticks that transmit disease agents.
True or False: Mechanical transmission requires development of the infectious agent in the vector.
False.