Flashcards in Exam 1 Deck (80):
Describes how traits are padded from 1 generation to the next. It looks at the individual organism and how it inherits it’s gene make up
Chemical nature of gene. Focuses on gene, structure, and function
Studies the genetic composition of the same species and how the composition changes. It focuses on a group of genes in a population
What makes a good model organism
Short generation time, adaptability to lab, a manageable number of progeny, and inexpensive to rear
What makes up a chromatin?
DNA wrapped around his tones. The Justine’s without linkers is called a nucleosome
What is a Karyn type?
Looking at a picture and chromosomes me features and size
What does a meta centric chromosome look like
The centromere is in the middle
What is a sub centric chromosome
Centromere is a little above middle
What is a Afrocentric chromosome
There are only tiny amounts of dna above centromere
What is a telocentric chromosome
Only centromere visible on top part of chromosome
What happens in interphase?
The chromosomes are replicated and the cell prepares
What happens during prophase?
The chromosomes condense and the spindle forms
What happens during metaphase?
The chromosomes line up along the middle metaphase plate
What happens during anaphase?
The chromosomes separate and go to separate poles. This phase has 2x # of chromosomes
What happens during cytokinesis?
When does crossing over take place?
What is different about meiosis?
In meiosis 1, the homologous chromosomes line up next to each other so when the cell divides the daughter cells are haploid
How many cells does meiosis end up with?
Does meiosis have 2 dna replication stages?
No only 1 before meiosis 1
What is the subunit of spindle fibers?
What do kinetochore microtubules do?
They shorten at the + end to pull the chromatids to opposite ends towards the - end
What do polar microtubules do?
The elongate the cell by adding to the + end while motor proteins move to the + end
What Jeep’s sister chromatids and homologous chromosomes together?
What breaks down cohesin
Why don’t sister chromatids separate during meiosis 1 when homologous chromosomes separate
Shugosin protects it
How many viable gametes from spermatogenesis?
How many viable daughter cells from oogenesis?
What are gametes called after first meiotic division?
Secondary spermatocytes and oocytes
What are gametes called after prophase 1?
Primary spermatocytes and oocytes
A synapses pair of homologous chromosomes
Close pairing of homologous chromosomes
Separation of chromosomes
Place where crossing over occurs
What are the 3 essential elements of a chromosomes?
Centromere, origin of replication, and telomeres
Pan genesis def
Early theory of genetics that genetic info from the body travels to the reproductive organs where it is transferred to gametes
A tiny version of the adult human( humunculus) is present in either sperm or egg
What is blending inheritance?
Theory that sperm and egg have essences that are blended
What did Mendel do differently?
Worked quantitively, used clear cut traits, true breeding
Alternate form of gene
Place occupied by allele on chromosome
2 of the same alleles
2 different alleles
Trait expressed in f 1
Trait not expressed in f 1
Cross with homozygous recessive to see the genotype(if homo or Herero)
Shows whether trait is sex linked by switching male and female
Crossing f1 with p
Homozygous for trait
Mendels 1st law
Alleles segregate during gamete formation, 1/2 have 1 allele half have other
Mendels 2nd law
Different genes assort independently in gamete formation
Multiplicative rule of probability
2 independent events, probability of happening together, multiply separate events
Additive rule of probability
2 independent events, you can find probability by adding probability
What are the 6 extensions of Mendelian genetics?
Pleiotropy, dominance variations, incomplete penetrative, variable expressivity, variations in viability, and gene interactions
One gene affects more than one trait
Phenotype of heterozygous is intermediate between the phenotype of the two homozygotes
The heterozygous phenotype includes phenotype of both homozygotes
Less than 100% of genotype shows correct phenotype
All of genotype show phenotype but there is some variation
Variations in viability
Some traits cause death of offspring before birth so you don’t see it in genotype
Multiple genes effect 1 trait
Dominant epistasis ratio
Recessive epistasis ratio
Duplicate recessive epistasis
Duplicate dominant epistasis
Dominant and recessive epistasis
Gender that can produce different types of gametes. Ex: male humans
Produce same genotype in gametes ex: female human
What are some of the sex determining mechanisms?
Haplodiploidy, which occurs in bees is where the haploid male undergoes mitosis to make a 1n sperm and the diploid female undergoes meiosis is to make 2 1n eggs. The egg that is fertilized is female and the egg that is not is male.
ZZ-ZW: males are ZZ, females are ZW
XX-XO: females XX, males X and then no other chromosome
Environmental sex determinism
Each individual can be male or female but not at the same time. Ex: limpet, the 1st is female, sequentially males then switches
How are drosophila different than humans in sex determinism?
Drosophila are male or female depending on the ratio of sex chromosomes to autosomal chromosomes
What is evidence for chromosomal theory of inheritance?
T.H Morgan and Calvin bridges
What is Turner syndrome?
Turner syndrome is a female with only One X chromosome. They are sterile with underdeveloped sex organs and a web of skin
What is Klinefelter syndrome?
A male with two X chromosomes and one Y who is sterile with underdeveloped sex organs and tall and lanky
How do you determine the most likely mode of inheritance? Autosomal recessive
Autosomal recessive traits appear equally in males and females and skip generations. They are more likely to appear in progeny if related parents
Autosomal dominant pedigree
Appear equally in males and females
Unaffected persons do not transmit the trait
Affected persons have at least one affected parent
X linked recessive pedigree
An affected male does not pass trait to sons but can pass to daughter making heterozygous and unaffected. X-linked recessive appear more frequently in males and a female who carries it can pass to sons who are affected.
X-linked dominant pedigree
X-linked dominant does not skip generations, affected males pass to all daughters
If affected females are heterozygous, they pass trait to half sons and half daughters
All male offspring are affected of a male who had trait