bio meisosis
Terms
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copy deck
- Antigen
- molecules protruding from the surface of cells/viruses which trigger an immune response
- antibody
- protein that attaches to antigens triggering macrophages to destroy that cell
- unviversal donar
- o-
- universal recipient
- AB
- multiple alleles
- more than two possible alleles in the abo blood type system
- Linked genes
- genes located on the same chromosome which tend to be inherited together in genetic crosses
- sex linked genes
-
genes located on the X chromosome
sinse the y chromosome is disheveled version of x chromosme, there are certain genes on the x that arent on the y
therefore there are certain traits tht men only have one copy of - hemizygougs
- 1 copy of a gene instead of 2
- autosomal genes
- genes located on autosomes
- carrier
- individual that has an allele for a trait/disease but who does not express it in their phenotype
- monohybrid cross
- a breeding experiment between parents differeing in only a single characteristic
- probability
-
the likelihood that a specific event will occur
^genetics - trait or characteristic that an offspring will exhibit - law of segregation
-
two alleles segregate(split) during gamete formation
ex: nondisjuntion - law of independent assortment
-
alleles of different genes separate independently of one another (inheritance of one trait has no effect on the inheritance of another trait)
ex: crossing over occurs - 4 reasons why peas are good to use
- many of the traits have two distinct formns, reproduce quickly, short generation time, and mating easily controlled
- gregor mendel
- austiran monk that had a background in farming and science. used pea plants to study heredity, mathematical aproach to science, and 1st to develop rules that accuratley predict patterns of heredity
- prophase 1
- homologous pairs form and crossing over occurs
- metaphase 1
- homologous chromosomes line up along the center of the cell but the homologous pairs remain side by side
- anaphase 1
- homologous chromosomes split and move to opposite ends of the cell
- telophase 1 and cytokinesis
- chromosomes move to either end of the cell and the cytoplasm divides creating 2 haploid cells. each cell contains one pair of hte homologous pairs
- prophase 2
- nuclear envelope disolves and spindle forms
- metaphase 2
- chromosomes line up along the center of the cell like mitosis
- anaphase 2
- centromeres divide and sister chromatids which are now chromosomes split and move to opposite ends of the cell
- telophase 2 and cytokinesis
- cytoplasm divides and 4 different haploid cells are created
- test corss
- cross in which an individual whose phenotype is domoinant but whose genotype is not known is crossed with a homosygous recessive individual
- somatic cells
- body cells (not reproductive)46
- gametes
- sex cells (egg and sperm)23
- binary fission
- form of asexual reproducton that makes identical offspring
- genes
- segment of dna that codes for a protein
- chromosome
-
structure found in the nucleus that contains one long strand of dna wrapped around proteins (forms as cell prepares to divide)
c - chromatids
- 2 exact copies of DNA that make up each chrom.
- centromere
- point of attachment between 2 chromatids
- homologous chromosomes
- chromosomes similar in size shape and genetic information *one comes from mom and one comes from dad
- diploid
- 2n=46 in humans -cell with 2 sets of chromosomes (somatic cells)
- haploid
- n=23 - cell with one set of chromosomes (gametes)
- zygote
- fertilized egg cell
- fertilization
- fusion of 2 haploid gametes to form a diploid zygote
- autosomes
- chromosomes not involved in determining sex (22 pairs)
- sex chromosomes
- chromosomes involved in deterning sex (1 pair-x and y chromosomes)
- humans missing 1 of 46 chromosomes
- DIE
- humans with 3 copies of one chromosme
- trisomy
- karyotype
- a photograph of chromsomes in a dividing cell that shows chromosomes arragned by size (helps to detect abnormalities)
- disjunction
- each chromosome and its homologue separate when a sperm and egg are formed
- nondisjunction
- when chromosomes fail to separate so a gamete gets 2 copies of a chromosome and not just one
- deletion
- piece of a chromosome breaks off
- duplicatoin
- chromosome fragment attaches to homologous chromosome which will now have 2 copies of certain genes
- inversion
- chromsome piece reattaches to original chromosome but in reverse orientation
- translocation
- chromosome piece attaches itself to a nonhomologous chromosome
- genotype
- set of alleles that an individual has
- phenotype
- physical appearance of a trait
- homozygous
- a genotype when two alleles of a particular gene are the same (BB or bb)
- heterozygous
- a genotype when two alleles of a particular gene are different (Bb)
- complete dominance
- one alllele is completely expressed while the other may have no observable effect on the organisms appearance
- dominant
- a trait that is expressed (in the phenotype( when either one or two copies of the allele are pressetn in the genotype
- recessive
- a trait only expressed when both copies of allele are present in the genotype
- incomplete dominance
- neither allele is completely dominant so if an individual is heteroxygous for the trait, a blending of the trait results
- codominance
- both traits are dominant and expressed in the phenotype at the same time-both traits appear rather than blended together
- moinogenic traits
- physical traits determined by a single type of gene
- polygenic traits w
- when several genes influence a single trait
- phenotypic gene
- one gene influences more than one physical trait
- environmental traits
- many phenotype physical traits are not simpley influenced by genes but are the result of an interaction between genes and the enviornment
- difference between meisosis and mitosis
-
2n->2n and 2n = mitosis
2n->n and n ->n n n n = meiosis