Chapter 6 Genetics Flashcards
What is heredity
the passage of characteristics from parent to offspring
What is DNA
a type of nucleic acid that contain sugar, deoxyribose
Where is DNA found
mainly in the nucleus but also in the mitochondria and cytoplasm
What are the 4 nitrogenous bases
A, G, C , T
What are genes
are small functional hereditary units located on a specific site of a chromosome
What is genetic code
making a specific protein
What is a codon
a triplet code necessary for protein synthesis
How many different amino acids are there
20
What is RNA
reading of the genetic code
What is mRNA ?
a template for protein synthesis dependent on a codon sequence that is based on that of the complementary strand of DNA
What are exons
pieces of the coding RNA that are retained
What are introns?
Segements of the RNA that are excised
What is tRNA
delivers products for protein production
What is rRNA
produced in the nucleolus and nuclear ribosomal proteins
What is translation
protein synthesis of the genetic code
What are chromatids
one of two strands newly formed during the early process of chromosome duplication
What is a centromere?
center region
What are telomeres
the tips of each chromosome are composed of DNA segments
What are histones
DNA is wound around spool-like protein cores
What is a diploid?
number of chromosomes
Autosomes
total number of chromosomes which is 46
Sex chromosomes
2 sex chromosomes X and Y or XX
Euploid Cells
multiple of the normal number of chromosomes
Triploidy
three copies of each chromosome
Tetraploidy
four copies of each chromosome
Aneuploidy
abnormal amount of chromosomes
Downs Syndrome (Trisomy 21)
three copies of one chromosome, intellectual disability, low nasal bridge, epicanthal folds, protruding tongue
Turner syndrome
only one copy of any chromosome, females with only one X chromosome, underdeveloped ovaries, short stature, webbing of neck, edema, underdeveloped breasts
Klinefelter syndrome
at least two Xs and one Y chromosome, male appearence, develope female-like breasts, small testes usually sterile, sparse body hair
Disjunction
normal separation of chromosomes during cell division
nondisjunction
usually the cause of aneuploidy, failure of homologous chromosomes or sister chromatids to separate normally during meiosis or mitosis
Deletion
breakage or loss of DNA, Cri du chat syndrome (cry of the cat), deletion of short arm chromosome 5, low birth weight, intellectual disability
- A person’s phenotype can be best described as:
a. the genetic makeup of an individual.
b. traits that are observable or apparent.
c. traits that are inherited in a recessive pattern.
d. traits that are inherited in a dominant pattern.
b. traits that are observable or apparent.
- A person’s genotype can be best described as:
a. the genetic makeup of an individual.
b. traits that are observable or apparent.
c. traits that are inherited in a recessive pattern.
d. traits that are inherited in a dominant pattern.
a. the genetic makeup of an individual.
- Which of these conditions follows a Mendelian pattern of recessive inheritance?
a. Coronary artery disease
b. Down syndrome
c. Marfan syndrome
d. Tay-Sachs disease
d. Tay-Sachs disease
- Which of these conditions follows a multifactorial pattern of inheritance?
a. Coronary artery disease
b. Down syndrome
c. Marfan syndrome
d. Tay-Sachs disease
a. Coronary artery disease
- Fortification of foods with folic acid has resulted in a significant reduction in the incidence of:
a. Huntington disease.
b. Turner syndrome.
c. neural tube defects.
d. cleft lip and palate.
c. neural tube defects.
- Which of the following chromosomal abnormalities can result in an inheritable form of trisomy?
a. Nondisjunction during meiosis
b. Balanced translocation
c. Insertion
d. Deletion
b. Balanced translocation
