Download Genetics Unit Review

Genetics Unit Review
These are the vocabulary words that you need to
know for the genetics unit. You need to study
them and quiz yourself using the castlelearning
flashcard assignment that is posted.
centromere
The region where the chromatids of a doublestranded chromosome are held together.
chromatid
acquired characteristic
A characteristic developed during an
individuals lifetime. These are not passed on to
succeeding generations.
addition
The adding of DNA nucleotides to a
chromosome.
allele
One of the two or more possible genes for a
trait. They are always at the same position (loci)
on homologous chromosomes.
amino acid
One of the two strands of a replicated
chromosome.
chromosomal mutation
Any change in the number or structure of the
chromosomes.
chromosome
A structure found in the nucleus that is made of
DNA and protein. It contains the hereditary
information.
Cloning
The production of genetically identical
organisms.
The basic building block of proteins. They
contain an amine group and a carboxyl group.
Codominance
Amniocentesis
A procedure that removes amniotic fluid
containing fetal cells for analysis to determine
the presence of genetic defects.
artificial selection
A breeding practice by which organisms are
purposely mated to produce offspring with
specific desirable traits.
autosomes
Inheritance in which both of the alleles are
expressed. The hybrid is a blend of both.
Codon
A sequence of three nitrogenous bases in the
messenger RNA sequence that are specific for
one amino acid.
common ancestors
Organisms from which closely related
organisms have evolved.
Chromosomes that are not sex chromosomes.
Complementary
Being the complement of the other, the result of
specific pairing.
crossing-over
The equal exchange of genetic material by
homologous chromosomes during the synapsis
of meiosis.
deletion
A chromosomal abnormality in which a portion
of the chromosome has been lost.
gene-chromosome theory
The theory that states that genes are arranged in
a linear sequence in definite locations (loci) on
chromosomes. Genes for the same trait are
located at the same loci on homologous
chromosomes.
genetic
diploid
Pertaining to DNA, the hereditary material.
The 2n number. The normal number of
chromosomes for a particular species. The
human diploid number is 46
genetic engineering
The process which transfers genes to another
organisms DNA resulting in recombinant DNA.
DNA (deoxyribonucleic acid)
The nucleic acid that stores the hereditary
information, that is, the genetic material.
genetic screening
The analysis of body fluids such as blood or
urine to detect the presence of a genetic disease.
double helix
The shape of the DNA molecule, the spiral
shape formed by the parallel strands.
genetically
Having to do with the chromosomes and how
traits are inherited.
environmentally influenced traits
Traits that are not expressed unless the
environmental conditions are correct.
genetics
gametes
The study of DNA and how the hereditary
information is transmitted from one generation
to the next.
Monoploid sex cells produced in gonads by
meiotic cell division. Sperm and egg.
gel electrophoresis
A method used to separate DNA fragments on
the basis of their size.
gene
A section of DNA on a chromosome that codes
for a particular trait.
gene mutation
Any change in the sequence of bases in DNA.
genotype
The genetic makeup of an individual; ex. hybrid
tall.
Heredity
The sum total of genetically inherited
characteristics which are passed from parents to
offspring.
Heterozygous
Hybrid. The pair of genes for a trait are not
alike; for example Tt.
homologous chromosomes
messenger RNA
A pair of chromosomes of the same size and
shape that carry genes for the same trait.
An RNA molecule with a specific code for a
polypeptide. This code is determined by the
sequence of bases of the DNA molecule in the
nucleus.
homozygous
Pure. The pair of genes are the same; for
example TT.
mutagenic agents
Any substance that can change the structure of
the DNA, causing a mutation.
identical twins
Two individuals formed from a single fertilized
egg. They have the same genetic makeup.
mutation
A change in the genetic material.
independent assortment
Different traits that are carried on different
chromosomes are inherited independently from
one another.
nitrogenous bases
Adenine, thymine, uracil, cytosine and guanine.
nucleotide
inherited
Coming from ancestors.
The basic unit of nucleic acids. It consists of a
5-carbon sugar bonded to a phosphate and a
nitrogenous base.
insertion
A mutation that is caused by the placement of a
DNA nucleotide into an existing gene.
Phenotype
The appearance of an organism; how it looks.
Insulin
A hormone produced by the Islands of
Langerhans in the pancreas. It lowers blood
sugar levels.
Protein
An organic compound made of amino acids.
karyotyping
protein synthesis
The process by which an individuals
chromosomes are examined by looking at
enlarged images of them arranged on a grid
according to size.
The making of a protein from amino acids by
matching the anticodon of the transfer RNA to
the codon of the messenger RNA.
male
recessive traits
Traits that do not appear if the dominant gene is
present.
recombinant DNA
An organism that has XY sex chromosomes or
produces sperm cells.
The DNA of an organism has been changed
usually by the addition of a gene.
Mendel
recombination
A mathematician and monk who developed the
hereditary principles of dominance,
segregation, and independent assortment.
The formation of new combinations of genes.
This can be the result of crossing over during
meiosis.
Template
replication
A guide for the assembly of products to assure
their uniformity.
The copying of the exact base sequence of the
DNA.
Tetrad
ribosome
The organelle that is the site of protein
synthesis in the cell.
The structure formed when the homologous
double stranded chromosomes (4 chromatids)
come together during the synapsis of meiosis.
Trait
selective breeding
The manipulation of reproductive processes to
produce offspring with specialized traits;
choosing mates or crossing traits to produce
offspring that have desired traits. Methods of
selective breeding include inbreeding, artificial
selection, hydridization, and vegetative
propagation. For example, dog breeds such as
the Dalmatian are the result of selective
breeding.
A characteristic of an organism.
transfer RNA
The type of nucleic acid that contains an
anticodon three nucleotides long. It carries a
specific amino acid to the mRNA at the
ribosome during protein synthesis.
tumor
sex chromosomes
The pair of genes that determines the sex of the
individual, with XX being female and XY
being male.
An abnormal mass of cells.
vegetative propagation
In humans, the male determines the sex. XX is
female XY is male.
A form of asexual plant reproduction that
produces identical new plants as
undifferentiated tissue divides by mitosis. The
resulting cells specialize providing the needed
tissues.
species
Watson and Crick
A group of organisms that can interbreed and
produce fertile offspring.
The scientists who discovered the structure of
the DNA molecule.
sex determination
sperm
The male monoploid (n) gamete, sex cell.
Tay-Sachs
A fatal recessive genetic disease which is
characterized by the deterioration of nerve
tissue due to the accumulation of fatty material.
It is most frequent in Jews of Central European
descent.