McCance Pathophysiology Chapter 4
Summary
Genes are composed - answer✔✔DNA
genes are located on - answer✔✔chromosomes
The most important constituent of DNA is the four types of nitrogenous bases, which are labeled
- answer✔✔A, C, G, T
DNA bases code for - answer✔✔amino acids, therefore making proteins
amino acids in DNA are specified by - answer✔✔Triplet codons of nitrogenous bases
DNA replication is based on - answer✔✔complementary base pairing
DNA polymerase is the primary enzyme involved in - answer✔✔replication
It adds bases to the new DNA strand and performs
"proofreading" functions
A mutation is - answer✔✔an inherited alteration of genetic material
Substances that cause mutations are - answer✔✔mutagens
The mutation rate in humans - answer✔✔ranges from 10-4 to 10-7 per gene, per generation
What is the difference between RNA and DNA? - answer✔✔-RNA is single stranded and DNA
is double stranded
-RNA also has uracil instead of thymine
transcription and translation - answer✔✔- occurs in the nucleus where the mRNA takes a copy
of DNA
- occurs in the cytoplasm with the help of ribosomes
- purpose is to produce proteins throughout the body ; DNA codes for that
, THEBRIGHT EXAM SOLUTIONS 8/20/2024 8:37 PM
Transcription is - answer✔✔A base-pairing event. mRNA takes the code to the ribosome in the
cytoplasm where the amino acids will be assembled.
Much of the RNA sequence is spliced from the mRNA before - answer✔✔the mRNA leaves the
nucleus.
-Excised sequences are introns
-Exons remain to code for proteins
MicroRNA's - answer✔✔small single-stranded RNA molecules that can bind to complementary
sequences in mRNA molecules (17-27 nucleotides in length)
Transcription factor-binding sites - answer✔✔The places in the genome where transcription
factors bind
Translation is - answer✔✔the process in which the genetic code in mRNA is read to make a
protein from the ribosomes
During translation, mRNA interacts with - answer✔✔tRNA, a molecule that has an attachment
site for a specific amino acid
Human cells consist of - answer✔✔diploid somatic cells and haploid gametes
Humans have - answer✔✔23 pairs of chromosomes; 22 of these pairs are autosomes.
-The remaining pair consists of sex cells, either X or Y
A karyotype is - answer✔✔an ordered display of all of an individual's chromosomes
How many live births have a major diagnosable chromosome abnormality? -
answer✔✔Approximately 1 in 150
Chromosome abnormalities are the leading cause of what? - answer✔✔Mental retardation and
miscarriage
polyploidy is the condition in which - answer✔✔an organism has more than two complete sets
of chromosomes
Somaticcells that do not have a multiple of 23 chromosomes are - answer✔✔aneuploid, which is
usually a result of nondisjunction
Trisomy is a type of aneuploidy in which - answer✔✔one chromosome is present in 3 copies in
somatic cells.
Monosomy is a type of aneuploidy in which - answer✔✔one chromosome is present in only one
copy of somatic cells