Transcript Genetics Vocabulary Spring 2011

Genetics Vocabulary
Spring 2014
Venable Biology
Genetics and Heredity
• The study of heredity
• The passing of traits from parents to offspring
Meiosis / Gametes
• The making of sex cells
• Gamete – sex cell; examples are sperm, egg,
pollen, ovule
Zygote
• A fertilized egg ; two gametes become one
Fertilization / Pollination
• The fusing or uniting of two gametes (into 1
cell) ; forms a zygote or seed
• When pollen reaches the stigma of the female
pistil of a flower
Stamen / Pistil
• Male reproductive part of the flower ; made of the
anther (holds pollen) and filament
• Female reproductive of the flower ‘ made of the
stigma (sticky top portion), style, and ovary
Chromosomes
• Strands of genetic information found in the
nucleus of a cell
Haploid / Diploid
• n; ½ the number of chromosomes than the normal
body cell (somatic cell) ; number of chromosomes in
the gametes of an organism ; ex. 23 in human
• 2n; two full sets of chromosomes in a normal body
cell; ex. 46 in human
Allele
• An alternative form of a gene (one member of a pair)
that is located at a specific position on a specific
chromosome ; each for a particular trait
• For example, the gene for seed shape in pea plants
exists in two forms, one form or allele for round seed
shape (R) and the other for wrinkled seed shape (r).
Trait
• Characteristics inherited from two parents ; A
genetically determined characteristic or
condition
Genes
• An allele that codes for a particular trait ;
Genes are segments of DNA located on
chromosomes. Genes exist in alternative
forms called alleles.
Genotype / Phenotype
• Gene combination that determines a trait ;
the genetic makeup of an organism
• The physical trait created by the genotype ; an
organism's expressed physical traits
Dominant / Recessive
• Allele that is seen of present ; represented
with a capital letter
• Allele that is masked / not seen unless paired
with another recessive allele ; lower case
letter
Dominant Alleles:
T, G, A, B
Recessive Alleles:
t, g, a b
Gregor Mendel
• Austrian monk who studied the garden pea
plant (7 different traits studied);
“The Father of Genetics”
Homozygous / Heterozygous
• Genotype were both alleles paired up are
identical ; ex. TT, tt
• Genotype were both alleles paired up are
opposite ; ex. Tt
Sex Chromosomes
• The 23rd pair of paired chromsomes in an
human somatic cell (The 1-22 pair are referred
to as AUTOSOMES).
• The sex chromsomes may be X or Y ; human males all
have a 23rd pair that is XY, females are XX
Karyotype
• A visual map of all the chromsomes of a person / organism ;
karyotyping is a test to examine chromosomes in a sample of
cells, which can help identify genetic problems as the cause of
a disorder or disease. This test can:
• Count the number of chromosomes
• Look for structural changes in chromosomes
Punnett Square
• Tool used in genetics to predict the outcome
of two parents offspring ; a type of grid used
to show the gametes of each parent and their
possible offspring; a type of grid that can
indicate all the possible outcomes of a genetic
cross
Pedigree
• Tool used to show the passing of disorders
within a family in genetics / it is an account of
the descent of a person or family traced
through a series of generations