Exam 3 - Basics Of Genetics Flashcards
What is the science of genetics concerned with
The inheritance or the transmission of biological material from parents to offspring
Gene
Unit of inheritance
Genome
Complete genetic material of the organism
Genotype
Genes of a given individual
Somatic cells
Most cells present throughout the body containing two copies of each chromosome
Sister chromatids
Identical copies of the DNA joined together by the centromere
Number of chromosomes in humans
46
Number of homologous pairs in humans
23
The complete genetic material of the organism is the genome, and the genome is dispersed across ________. The number of __________ is _______ ___________
Chromosomes; chromosomes; species dependent
Karyotype
Number and type of chromosomes that make up an individual’s genome
What are autonomies
Non sex-chromosomes
Gametes
Reproductive cells in which chromosomes exist as only a single copy
The first meiotic division is a _______ ________
Reduction division
Inheritance
Transfer of genetic material from parents to offspring
Gregor Mendel
Father of modern genetics, pea plants
What are the two distinct factors that control inherited characteristics
One from the male parent, one from the female parent
T or F Traits bust be observed to be passed to the next generation
False; traits may not be observed in an individual but can be passed to the next generation
Name the 2 laws of inheritance
Law of segregation, independent assortment
Meiosis: result of cell division 1
1 diploid cell becomes 2 haploid daughter cells
Meiosis: Cell division 2
2 haploid cells become 4 haploid daughter cells
Law of segregation
Only one randomly closed chromosome is found within a gamete
Independent assortment
Alleles of genes on non homologous chromosomes sort independently into the final gamete
Alleles
Are different forms of genes at a locus on corresponding homologous chromosomes
AA, Aa, aa
Known as the genotype
4 modes of inheritance
Dominant and recessive, incomplete/partial dominance, co-dominance, sex-inherited traits
Dominant alleles (A) ________ recessive alleles (a) and ________ _________ of the gene at the corresponding loci on the homologous pair
Overpower; prevent expression
Recessive alleles (a) represent the corresponding gene code that is ‘________’ by the dominant allele (A) at the corresponding loci
Masked
Incomplete/partial dominance
The allele is expressed in a dose dependent manner
Co-dominance
Neither allele masks the other and both are expressed in heterozygous state
When co-dominance occurs and an animal inherits red color gene from one parent and white color gene from the other parent it is expressed as ________ color in the ____________ ________
Roan; heterozygous state
The three different types of sex-inherited traits
Sex-linked, sex-limited, sex-influenced
________ are patterns of inheritance as simply as complete dominance
Rarely
Sex-linked
When a gene is found within regions of the X chromosome that do not share homologous with the Y chromosome
In all female mammalian cells, at a certain point during embryogenesis, one of the two ___ chromosome in every cell is __________ __________/__________
X; randomly inactivated/deleted
A female cat with heterozygous XbXB will be a ___________ of __________ and ________
Patchwork; orange; black
Sex-limited
Traits limited to only one sex even though both sexes carry the trait
While both makes and females carry genes that underscore this train, only the females express the genes for this trait (an example of sex-limited traits)
Milk production in females
Sex-influenced
Reciprocal expression of the trait occurs in males compared to females
Sex-influenced traits of a male sheep
Horned allele is dominant, polled is recessive, in heterozygous state horned is expressed
Sex-influenced traits of a female sheep
Polled allele is dominant, horned is recessive, in heterozygous state polled is expressed
Epistasis
Expression of one gene is controlled by gene at a different locus
Lab color will be dertimined by the ______ loci (B) and the ________ pigment loci (E)
Black; extension
There there is a dominant E at the extension loci the lab will be either ________ or ___________
Black; chocolate
