bio 15 Flashcards
genotype
the genetic makeup of a cell or organism; the particular combination of alleles present in an individual
phenotype
the expression of physical, behavior, or biochemical trait; an individual’s observable height, weight, eye color, and so forth. influenced by genotype and environment
polymorphism
any genetic difference among individuals sufficiently common that it is likely to be present in a group of 50 randomly chosen individuals
allele
the different forms of a gene, corresponding to different DNA sequences in each different form
homozygous
describes an individual who inherits an allele of the same type from each parent, or genotype in which both alleles for a given gene are the same
heterozygous
describes an individual who inherits different types of alleles from the parents, or genotypes in which the two alleles for a given gene are different
SNP(single-nucleotide polymorphism)
A site in the gametes where a base pair differs among individuals in a population
AA
normal ability to carry oxygen
normal blood cells
no malaria protection
SS
very low ability to carry oxygen
sickle blood cells
CC
slightly lower ability to carry oxygen
normal blood cells
strong malaria protection
AS
reduced ability to carry oxygen
slightly abnormal blood cells
partial malaria protection
AC
normal ability to carry oxygen
normal blood cells
good malaria protection
Variable Number of Tandem Repeats
genetic difference in which the number of short repeated sequences of DNA differs from one chromosome to the next
First-divison nondisjunction
not genetically identical
homogous fail to separate
2 gametes with extra chromosome, 2 with none
failure of bivalent in anaphase I fails to separate
failure of chromosome separation in meiosis I
Second-divison nondisjunction
sister chromatids fail to separate
two copies of a chromosome end up in same gamete and are genetically identical
disjunction in the second meiotic division
nondisjunction
can lead to lineages with extra or missing chromosomes, and can happen in meiosis I or II
XYY, XXX
nondisjunction in sex chromosomes with no phenotype
Not normal genotype, normal phenotype
XXY- klinefelter
X0- Tuner’s
nondisjunction in sex chromosomes with an effect on phenotype and disease associated with them
Klinefelter
sex-chromosome abnormality in which an individual has 47 chromosomes, including two X chromosomes and one Y chromosome. infertile male, small testes, some mental impairment
Turner’s
A sex-chromosome abnormality in which an individual has 45 chromosomes including only one X chromosome
growth impaired female, usually normal cognition
Autosomal
any chromosome other than the sex chromosome
unequal meiosis , 1 haploid daughter cell, 3 polar bodies
female meiosis yields..
equal meiosis, yeilds 4 haploid daughter cells
male meiosis yields..
