The characteristics of an individual
A part of DNA that encodes a functional RNA or protein product, and is the molecular unit of heredity.
Genetic constitution of an organism
Observable and non visible trait or set of traits of an organism produced by the interaction between its genotype and the environment.
The extent to which the potential for developing a particular phenotype depends on environmental influences.
Different forms of a gene
Mating between two individuals, leading to the fusion of gametes
one set of chromosomes in each cell
two homologous sets of chromosomes.
unchanged trait from parents to offspring for many generations. Usually means that there's homozygosity for the allele for the trait.
It's for confirming the principle of segregation and used to determine the genotype of a mystery individual.
Dominant and Recessive
If a gene's product is a mutated enzyme then its product is recessive. But, if the gene's product is a mutated structural protein then it will be dominant.
Single gene traiits
caused by individual mutant genes
Incomplete dominance, sickle cell
Autosomal Dominant Disorder
Aa * aa
mutant gene is dominant over normal gene
Present in all generations
Affected number equal in men and women
one affected person, have atleast one affected parent
Hereditary breast and ovarian cancer
`Aa * Aa
If more than one person is affected, it's usually the sibling of the affected person
Affected skipping generations
It's a special case where an affected homozygous marries a carrier. The first part of the pediree shows likea dominant disorger, but the rest of the pedigree shows like recessive mode of inheritance.
states that there is no real difference between the observed data and the predicted data
used to determine whether the difference is due to chance.
simple statistical analysis used to test null hypotheses
sum of observed minus expected squared over expected
centromere in the center, each arms of equal length.
centeromere slightly offset from the center. slight asymmetry in the length of the two arms.
centromere severely offset from the center leading to one very long and one very short arm.
centromere at the very end of the chromosome
the nucleus and the nuclear envelope are distinct and the chromosomes are in the form of threadlike chromatin
Chromosomes condense and the nuclear envelope is not apparent
chromosomes line up in the center of the cell on the metaphase plate, and spindle fibers are attached to chromosomes.
Chromosomes have separated and are moving toward the poles.
chromosomes are at the poles, and the nuclear envelope is re forming and cytoplasm starts dividing.
Meiosis 1 vs Mitosis
Prophase: In meiosis, crossing over occurs between homologous chromosomes in tethrads' and in mitosis there is no crossing over.
Metaphase: In meiosis, the tetrads align at the metaphase plate while in mitosis, chromosomes align at the metaphase plate.
Anapahse and telophase: In meiosis, homologous chromosomes separate into four daughter haploid cells, whereas in mitosis, the sister chromatids seperate into two haploid cells.