Chapter 1 Gen Flashcards
(37 cards)
Genome
DNA found within all of our chromosomes
Gene at the molecular level
46 human chromosomes were found in 23 pairs
Transcription
the process of synthesizing RNA from a DNA template. or making a copy of it
Translation
the process in which the sequence of codons within mRNA provides the information to synthesize the sequence of amino acids that constitute a polypeptide.
Molecular level
Pigmentation gene
Cellular Level
How the pigment is observed, to either be a little or a lot, in cells
Organism Level
Looking at the creature and seeing if the pigment is there or not
Population Levels
How this pigmentation affects a whole society of related creatures
Gene Expression
the process by which the information within a gene is accessed, first to synthesize RNA and polypeptides, and eventually to affect the phenotype of the organism.
The central dogma of biology/life
the idea that the usual flow of genetic information is from DNA to RNA to polypeptide (protein)
Genetic code
the correspondence between a codon (i.e., a sequence of three bases in an mRNA molecule) and the functional role that the codon plays during translation. Each codon specifies a particular amino acid or the end of translation.
The basic structure of DNA
Composed of a linear sequence of nucleotides. With four nitrogen-containing bases: adenine, thymine, guanine, and cytosine.
How DNA encodes information for proteins
The sequence of a gene determines the amino acid sequence for the protein it encodes.
Allele
an alternative version of a specific gene
How alleles determine traits
They encode proteins that function as a blank-synthesizing enzyme
How Proteins Determine Cellular Phenotypes
The unique relationship between gene sequences and protein structures is of paramount importance because the distinctive structure of each protein determines its function within a living cell or organism.
How does this variability lead to a population that is enriched for a particular
trait that blends with the habitat following the action of natural selection
such as predation with respect to butterflies with different alleles for
pigmentation gene.
The butterflies with dark wings would avoid being eaten by birds if they lived in the dim light of a forest. The dark wings would help camouflage if the butterfly was perched on a dark surface like a tree trunk. The light-colored wings would help to camouflage the butterfly inhabiting a brightly lit meadow. A bird may be less likely to notice this butterfly if it is perched on a sunlit surface.
How a mutation in the coding region of a gene may lead to
a change in the amino acid sequence of the corresponding polypeptide
A mutation in one nucleotide could change a codon to make a different amino acids, changing the polypeptide.
The example of variability with respect to the sickle cell allele for
Hemoglobin and how it causes sickle cell anemia when present in
homozygous condition but offers a protective function against malarial
infection when present in the heterozygous state. Be able to justify why this
allele continues to be maintained in populations.
-In the homozygous condition: Only hemoglobin S is produced rather than the normal hemoglobin A. The red blood cells are then deformed into sickle-shaped cells after being subjected to low levels of oxygen. -In the heterozygous state: Sickle cell disease is not present, however, people benefit by an increased resistance to malaria. Red blood cells infected with malaria are likely to rupture, preventing the disease from spreading
Be able to explain how the environment influences traits by interacting with genes using the example of phenylketonuria caused due to phenyl alanine hydroxylase deficiency.
Phenylketonuria (PKU): Humans possess a gene that encodes an enzyme known as phenylalanine hydroxylase. Most people have 2 functional copies of this gene. People with 1 or 2 functional copies of this gene can eat foods containing the amino acid phenylalanine and metabolize it properly. It’s rare for people to get 2 copies of a nonfunctional version of this protein which means that they cannot metabolize phenylalanine properly (about 1 in 8,000 births among Caucasians in the USA). People with this disorder can manifest a variety of detrimental traits, including mental retardation, underdeveloped teeth, and foul-smelling urine. PKU individuals can be identified at birth and raised on a restricted diet that is low in phenylalanine and they can develop normally.
Karyotype
A photographic representation of all the chromosomes within a cell. It reveals how many chromosomes are found within an actively dividing somatic cell.
Haploid
Contains half the number of chromosomes (23) (Ex: gametes: sperm and egg)
What makes haploid cells?
Produced during meiosis, which is a cell division
Diploid
Contains 2 copies of each chromosome, one from each parent. (Humans have 46 chromosomes, which are found in homologous pairs, except the sex chromosomes X and Y) -Process: Meiosis
