Chapter 5: Genetic Control Of Cell Function and Inheritance Flashcards
Define mitosis
mitosis: A type of indirect cell division that occurs in somatic cells and results in the formation of two daughter nuclei containing the identical complements of the number of chromosomes characteristic of the somatic cells of the species.
Define meiosis
meiosis: The division of a sex cell as it matures, so that each daughter nucleus receives one half of the number of chromosomes characteristic of the somatic cells of the species.
Define karyotype
karyotype: The total chromosomal characteristics of a cell; or the micrograph of chromosomes arranged in pairs in descending order of size.
What is a gene?
A gene is a locatable segment or segments of DNA sequence that encodes a set of functional products, typically proteins
p
proteome is a relatively new term, created to define the complete set of proteins encoded by a genome.
n
nucleotides, which consist of phosphoric acid, a five-carbon sugar called deoxyribose, and one of four nitrogenous bases. These nitrogenous bases carry the genetic information and are divided into two groups: the pyrimidine bases, thymine (T) and cytosine (C), which have one nitrogen ring; and the purine bases, adenine (A) and guanine (G), which have two.
c
chromosomes, discrete bundles made up of one continuous, linear DNA helix
n
chromosomes, discrete bundles made up of one continuous, linear DNA helix
cA sequence of three of these bases forms the fundamental triplet code for one of the 20 amino acids used in protein synthesis in humans. This triplet code is called a codon.
h
l
Several repair mechanisms exist, and each depends on specific enzymes called endonucleases that recognize distortions of the DNA helix, cleave the abnormal chain, and remove the distorted region. The gap is then filled when the correct nucleotides, identified by a DNA polymerase using the intact complementary strand as a template, are added to the cleaved DNA. The newly synthesized end of the segment is then joined to the remainder of the DNA strand by a DNA ligaser
h
It is the small DNA sequence variation (one in every 1000 base pairs) that is thought to account for the individual differences in physical traits, behaviors, and disease susceptibility. These variations are sometimes referred to as single nucleotide polymorphisms (from the existence of more than one morphologic form in a population), or SNPs
i
a genome-wide map of these variations as haplotypes (a combination of SNPs at adjacent locations which are inherited together) with the intent of providing a link between genetic variations and common complex diseases such as cancer, heart disease, diabetes, and some forms of mental disease (the International HapMap Project is discussed in the section under gene technology).
mtDNA
mitochondrial DNA
g
Genetic disorders of mtDNA, although rare, commonly affect tissues such as those of the neuromuscular system that have a high requirement for oxidative metabolism
Which ribonucleic acid (RNA) structure translates the instructions and provides the machinery for protein synthesis? Transfer RNA Messenger RNA Instructor RNA Ribosomal RNA
Ribosomal RNA
r
RNAdiffers from DNA in three aspects of its structure. First, RNA is a single-stranded rather than a double-stranded molecule. Second, the sugar in each nucleotide of RNA is ribose instead of deoxyribose. Third, the pyrimidine base thymine in DNA is replaced by uracil in RNA.
g
Genes are transcribed by enzymes called RNA polymerases
Where does the complex made of polymerases bind to the DNA?
This complex binds to the double-stranded DNA at a specific site called the promoter region. Within the promoter region is the so-called “TATA box” that contains the crucial thymine-adenine-thymine-adenine sequence that RNA polymerase recognizes and binds to, starting the replication process (
e
This complex binds to the double-stranded DNA at a specific site called the promoter region. Within the promoter region is the so-called “TATA box” that contains the crucial thymine-adenine-thymine-adenine sequence that RNA polymerase recognizes and binds to, starting the replication process (
What are the majority of the proteins made from DNA?
This complex binds to the double-stranded DNA at a specific site called the promoter region. Within the promoter region is the so-called “TATA box” that contains the crucial thymine-adenine-thymine-adenine sequence that RNA polymerase recognizes and binds to, starting the replication process (
w
There are three types of RNA: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)
What is a peptide? What is a polypeptide?
A compound consisting of two or more amino acids linked in a chain. A polypepetide is a chain of 100 to 3000 amino acids.
Hoe does mRNA get out of the nucleus and into the cytoplasm?
it diffuses through the nuclear pores.
What is the mysterious complex going into my TATA box?
RNA polymerase along with transcription factors
c
The folding of many proteins is made more efficient by special classes of proteins called molecular chaperones.
d
Disruption of chaperoning mechanisms causes intracellular molecules to become denatured and insoluble. These denatured proteins tend to stick to one another, precipitate, and form inclusion bodies. The development of inclusion bodies is a common pathologic process in Parkinson, Alzheimer, and Huntington diseases.
g
The degree to which a gene or particular group of genes is active is called gene expression
t
transcription factors can function to increase or decrease transcriptional activity of the genes.