Genetics Flashcards
Genetics
Study of how traits are passed from parent to offspring
Heredity
Passing of genetic information from parent to offspring through reproduction (Inderidance)
DNA
Hereditary information
What does the sequence of the bases of DNA do?
They are a code for the making of a trait/protein for the organism
The nucleus contains
chromosomes
Genes
section of chromosomes that determines traits/charactoristics
most complex to least complex
cell
nucleus
chromosomes
genes
DNA
Sexual reproduction
Due to the process of meiosis in forming sperms and eggs, each parent will give the offspring 1/2 of their chromosomes. The offspring will be a combination of each parents..
Segregation
Separation of the homologous chromosomes during meiosis. Gametes separate from their homologous
Recombination
New combination of homologous chromosomes is created during fertilization.
Linked genes
Genes on the same chromosome will usually move together in meiosis. Ex: red hair and freckles
Crossing over
Exchange of a portion of homologous chromosomes during meiosis.
Variation
Variation happens due to segregation, recombination, and crossing over.
Self Pollination
Sperm and egg from the same flower.
Cross Pollination
Sperm and egg from different flowers.
Traits
Characteristics that appear in organisms
homologous pairs
same size and Carrie genes for the same traits but form of gene (allele) may differ.
Hybrid
plant that has descended from parents with different forms of a trait (heterozygous)
F1 Generation
Purebred round x Pure wrinkled
(All offspring appeared round, but still are hybrids)
F2 Generation
Hybrid x Hybrid
(3 round and one wrinkled appeared)
Law of segregation and recombination
these factors in the parents separate in the forming of sex cells and recombine in the offspring (meiosis and fertilization)
Dominant/recessive
The dominant allele will always be expressed if at least one is present. Recessive traits are only expressed if both alleles are recessive.
Gregor Mandel
Known as “Father of Genetics”
Studied traits in pea plants
Studied Reproduction in Flowers
process of plant fertilization
1.) sperm are in pollen on another
2.) Eggs in ovaries
3.) Sperm land on stigma and travels down pistol
4.) Seed forms and ovary becomes fruit
Genotype
Two alleles an organism has for a trait. Ex: characteristic, seed color
Phenotype
How the trait is shown in the individual’s physical appearance
homozygous/purebred
Both alleles are the same
Heterozygous/hybrid
Different alleles
Tt
heterozygous/hyrdrid
dominant shows
TT
Homozygous/purebred
dominant shows
Incomplete Dominance
Two alleles can blend to form an intermediate trait. Straight hair allele and curly hair allele blend to show wavy hair.
tt
homozygous
ressesive shows
Co-dominance
Two different alleles can both show up in the organism.
Poly genetic traits
some traits involve more than one set of genes. Height in humans
Punnet squares
Used to predict the possibility of traits appearing in the offspring
