biology review
Spindle
(biology) tiny fibers that are seen in cell division
If two pink flowered snapdragons are crossed, what is the chance that one of the offspring will have red flowers?
25%
If a mother is heterozygous for the hemophilia gene, and the father is normal, what is the chance that their MALE children will have hemophilia?
50%
In humans, if a person has the blood type genotype IAi, their blood type is
A BLOOD
Binary fusion
A form of asexual reproduction that produces identical offspring.
Trisomy
A genetic condition of having three chromosomes instead of two. The conidtion causes various birth defects
Gene
A segment of DNA that codes for a protein or RNA molecule.
If a human has one allele for the A blood antigen, and one allele for the B blood antigen, their blood type is.
AB blood
Homologous chromosomes
Chromosomes that are similar in size, shape, and genetic content
allele
Different forms of the same gene are referred
X-linked
Genes that are present on the X chromosome but not the Y chromosome
homozygous
If an individual has two alleles that are the same, the individual is _______ for the gene.
Heterozygous
If an individual has two different alleles for a given gene, the individual is ____ for the gene
Gene linkage
Inheritance of genes as a group because they are on the same chromosome
Does (Mitosis or Meiosis ) involve two cell divisions
Meiosis
Chromosome
The DNA and the proteins associated with the DNA
Recessive
The allele that is expressed only in homozygous and is completly masked in heterozygotes
pleiotrophy
The phenomenon in which one gene influences MANY traits is referred to as
short sature
The phenotype of an individual who is homozygous for the abnormal growth hormone gene (dd)is.
Chromatid
The two exact copies of DNA that make up each chromosome.
Homozygous recessive
When both alleles are recessive, the organism is said to be ________ ___________ for the gene.
recessive
When one allele is not expressed, and seems to be 'dominated' by the other allele, it is called the ________ allele.
Trisomy 21
a congenital disorder caused by having an extra 21st chromosome
Gamete
a mature sexual reproductive cell having a single set of unpaired chromosomes
Autosome
all animals have one pair of sex chromosome and a variable numbers of other chromosome, the other 22 chromosomes found in both sexes
dominant
an allele that can determine the phenotype of a heterozygotes completly, such that they are inditinguish from individuals homozygous for the allele, in the heterzygotges, the expression of the other(ressive) allele is completly masked
Haploid
an organism or cell having only one complete set of chromosomes
Autosome
any chromosome other than a sex chromosome
pedigree
are diagrams showing the genetic relationship among a set of related individuals
Centromere
area where the sister chromatids of a chromosome are attached
co dominance
both alleles are fully expressed , equal phenotype expression of both alleles when heterozygous
Homozygous
carrying two copy of the same allele of a given gene
Allele
different versions of a gene at a given locus
Cytokinesis
division of the cytoplasm
Zygote
fertilized egg
Alleles are alternate forms of the same
gene
epistatic genes
genes that affect the phenotype expression of other genes
Sex linkage
genes that are found on one sex chromosome but not on the other
Meiosis produces cells that are
genetically different
Homozygous chromosomes are chromosomes that
have the same gene in the same location
Heterozygous
having two different alleles for a trait
true breeding
homozygous organisms have two copies of the same allele for a given gene, hybrid( heterozygous) organism have two diffrent alleles for a given gene
Mitosis
in eukaryotic cells, a process of cell division that forms two new nuclei, each of which has the same number of chromosomes
law of independent assortment
independent inheritance of two or more distinct traits
polygenic inherintance
inheritance that involves MANY genes acting together to influence a trait
test cross
is conducted to determine the gene condition of a single individual
incomplete dominance
neither allele is dominant
inhertance
occurs when a gene transmited from parent to the offspring, genetic transmition of characteristics
Diploid
of a cell or organism having two sets of chromosomes or twice the haploid number
Nondisjunction
of sex chromosomes in males produces sperm that have two sex chromosomes (xx,yy or yx) or that have no sex chromosomes at all (0)
Sex chromosome
one of two chromosomes of the 23rd pair of human chromosomes, which determine an individual's gender
self fertilization
pea egg cell in a pea flower fertilized by sperm from the same flower
Interphase
period of the cell cycle between cell divisions
Karyotype
the appearance of the chromosomal makeup of a somatic cell in an individual or species (including the number and arrangement and size and structure of the chromosomes)
incomplete dominance
the pattern of a heterozygous phenotype si intermediate between the two homozygous phenotypes
coedominance
the pattern of inheritance when heterozygotes express phenotypes of both of the homozygotes
Cell Cycle
the regular sequence of growth and division that cells undergo
cross-fertilization
when a sperm from one organism fertilizes eggs from a different organism
Non- disjunction is
zero of a particular chromosome or two of a particiular chromosome