Test 1 Fundamental properties of living organisms o Evolution all life has a common ancestor traits are passed on but change over time our common ancestor had DNA o Structure and Function mitochondria is a highly folded membrane to increase surface area and cellular respiration more surface area more ATP o Reproduction and Inheritance DNA has the properties Functions of cell division o Reproduction 1 parent splits in 2 o Growth and development all cells divide over and over o Repair and maintenance cells die injury Stages of Mitosis o Interphase o Prophase centrioles migrate to opposite sides DNA condenses nuclear membrane breaks down o Prometaphase o Metaphase chromosomes line up in the middle o Anaphase sister chromatids split in 2 are pulled apart by microtubules o Telophase strands uncoil and cell divides Mitosis is part of a Cell Cycle stages of the cycle o Interphase everything outside of mitosis contains G1 S G2 o G1 growth and does whatever its job is o G1 checkpoint big stopping point for a lot of cells o S DNA gets copied o G2 does its job growth o G2 checkpoint causes cells to move into mitosis o Mitosis o M checkpoint cell can stop or keep going Chromosomes exist as homologous pairs in diploids Meiosis produces haploid daughter cells from diploid parents o Diploid cell pairs of homologous chromosomes o Each chromosome 2 chromatids o Homologous chromosomes same set of genes but not necessarily the same code brown blue eyes o Sister chromatids code for genes is exactly the same on each side o Diploid 6 chromosomes homologs are in a pair o Haploid 3 chromosomes only one of each homolog Meiosis I Anaphase I separates homologous chromosomes o Prophase I homologous pairs attach crossing over happens here Meiosis II Anaphase II separates sister chromatids o Produces 4 haploid cells b c homologs attach Meiosis produces variation through random segregation of Meiosis increases variation through crossing over during synapsis chromosomes at the chiasma Law of Segregation o Alleles segregate and one gets passes on o 3 1 phenotypic ratio 3 Purple 1 White o 1 2 1 genotypic ratio PP Pp Pp pp Law of Independent Assortment o Dihybrid cross o Round wrinkled yellow green example o Each pair of alleles segregates independently of the other pair of alleles during gamete formation Mendel s hypothesis particulate inheritance genes are passed on but stay as a particular unit How meiosis relates to the Law of Independent Assortment o Chromosomes can combine randomly and produce many different combinations in the offspring o It applies to genes located on chromosomes that not homologs Genes located near each other on the same chromosome tend to be inherited together o If the word or occurs in the statement the probabilities Sum Rule are added Product Rule o If a statement contains the word and the probabilities are multiplied Patterns of inheritance with Incomplete Dominance o Both alleles are expressed to give an intermediate form between homozygotes o Codominance both alleles are expressed to give a different phenotype than either homozygote Pattern of inheritance for a dominant trait in a pedigree o Trait is passed directly from parent to child usually o If you have the allele one of your parents has it too Pattern of inheritance for a recessive trait in a pedigree o If allele is recessive almost all the copies in the population will be heterozygotes o They are the carriers Patterns of inheritance with multiple alleles o Multi locus Inheritance some traits are determined by more than one locus o Additive Inheritance incomplete dominance over many loci overall affect done by adding up all results height is affected by many genes Genetic test crosses can reveal the location of genes on particular chromosomes o Test cross with the recessive Loci on the same chromosome are said to be linked and may not be inherited independently o Parental linkage individual chromosome has the genotype or phenotype of the parental generation o Recombinant individual chromosome has a different combination of alleles phenotypes than the parental types Test 2 The development in plants is an ongoing process Meristems are sites of cell division and development follows Genes can be controlled at multiple stages in gene transcription DNA methylation transcription RNA modification RNA transport translation Methylation attachment of methyl groups to the DNA makes the DNA permanently not able to transcribe Control of transcription occurs through the binding of activators or repressors to special sites on the DNA o Exons get translated o Introns get spliced out Cell differentiation occurs during early development because of different concentrations of cytoplasmic determinants mother provides the CDs o Determined set on a pathway to become something but o Differentiation cell has taken on a specialized phenotype no change in phenotype yet control genes are expressed The earliest genes expressed determine axis polarity bicoid followed by organization into body regions Hox Genes o Bicoid is a CD organogenesis Development consists of fertilization cleavage gastrulation and Cleavage has different patterns in different organisms o Rapid series of mitotic cell divisions that occur in the absence of cell growth the whole thing stays the same size and the individual cells divide and get smaller o 2 groups protostomes and deuterostomes o Protostomes have spiral and determinate cleavage o Deuterostomes have radial and indeterminate cleavage Gastrulation is the folding in of the blastula on itself o Sea urchin is microlecithal and holoblastic o Frog is mesolecithal and holoblastic o Chick egg is macrolecithal and meroblastic Gastrulation produces three basic types of embryonic cells o Microlecithal small yolk o Mesolecithal moderate yolk o Macrolecithal large yolk An important example of organogenesis is neurulation the formation of the embryonic nervous system Experiments have demonstrated that certain areas of embryos provide positional information o Gray crescent forms the dorsal region o Zone of polarizing activity ZPA cells at the top and bottom weak dosage sets up anterior posterior axis of limb o Apical epidermal ridge AER cells at the end of the wing strong dosage sets up proximal distal axis of limb Loci on the X chromosome are inherited differently in males and in females o For males its what you get from your mother that determines what you express Induction one cell releases substances that affect other cells near it In
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