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117 Cards in this Set
- Front
- Back
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Where does DNA unwind?
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in the nucleus
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What are the copies of the DNA onto?
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Messenger RNA, and once its copied it leaves the nucleus
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Once mRNA leaves the nucleus, where does it go?
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to the ribosome where the DNA sequence is read and a protien is made
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How big is the human genome?
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20,000 to 25,000
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Name an example of a cell that is made in the first parts of life and never divide?
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brain cells
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Name an example of a cell that is constantly dividing
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bone cells
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Name the steps of DNA replication
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the double helix unwinds and then bases bond with each side
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chromosomes
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packaged and divided DNA
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What does DNA form when it is wrapped around a protein before becoming a chromosome?
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chomatin
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chromatid
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one of the two identitical strands of chromatin that make up a chromosome
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homologous chromosomes
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a pair of chromosomes that are the same in size and function
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karyotype
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a pictorial arrangement of a complete set of human chromosomes
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mitosis
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the seperation of a cells duplicated chromosomes prior to cytokinesis
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Name the two main parts of the cell cycle
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interphase and miotic phase
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interphase
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the portion of the cell cycle in which the cell simultaneously carries out its work and duplicates its chromosomes
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mitotic phase
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the portion of the cell cycle that includes both mitosis and cytokinesis
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Name the parts of interphase
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G1 S G2
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G1
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the phase of interphase that has cell growth
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S
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the phase of interphase that duplicates its DNA
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G2
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the phase of interphase that has cell growth in prep for mitosis
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Name the phases of the Mphase
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prophase, metaphase, anaphase, and telophase
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prophase
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nucleus breaks down, centrosomes move apart
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centrosomes
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cellular structure that acts as an organizing center for the assembly of microtubules (spindle fibers)
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metaphase plate
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the part of the cell where all of the seperating happens
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mitotic spindle
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microtubules that are active in cell division
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metaphase
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chromosomes are attached in the middle
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anaphase
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the sister chromatids separate, spindle fibers shorten making each chromosome closer to the poles
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telophase
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chromosomes loosen, nuclear membranes form
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cytokinesis
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it begins during anaphase, contractile ring makes cleavage furrow, two cells are formed
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What is the difference between plant and animal cell division?
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plants have their cell walls outside of the membrane so they grow a wall in the middle
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What happens when bacteria divides?
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there is only one chromosome so it divides, attaches to the membrane, septum is formed, cell breaks into two
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binary fission
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prokaryotic cell division that is completed in 20 mins
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oncogenes
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accelerator genes that are stuck in cell division
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What is the name of the protein that prompts cell division to start and stop?
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ras
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What is the body's first line of defence to cancer?
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p53
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apoptosis
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cell suicide
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gametes
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sex cells
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haploid cells
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are reduced in number aka gametes
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Name the differences in meiosis and mitosis
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meiosis has 4 cells, seperation of homologous chromosomes not tids
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What are the major parts of meiosis
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meiosis 1 and meiosis 2
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Meiosis 1 - Prophase 1
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chromosomes pair up to make tetrads (crossing over), the chromosomes unwind still remaining overlapped
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Meiosis 1 - Metaphase 1
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the chromosomes line up with the maternal on one side and paternal on the other
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Meiosis 1 - Anaphase 1
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microtubules pull the homologus chromosomes apart
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Meiosis 1 - Telophase 1
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cytokinesis happens and 2 haploid cells are created
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Meiosis 2
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repeate the steps of mitosis
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independent assortment
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the random distribution of homologous chromosomes during meiosis
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crossing over
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homologous pairs exchange reciprocal portions
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oogonia
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formation of eggs
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spermatogonia
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formation of sperm
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primary oocyte and primary spermatocytes
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made from oogonium and spermatogonium that are going to be duplicated
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What happens during spermatogonia?
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spermatogonium make primary spermatocytes, they undergo meiosis making secondaryspermatocytes, then undergo meiosis2 to make four haploid spermatids
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flagellum
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tail on sperm
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What happens during oogonia?
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oogonia gives rise to primary oocytes who are paused in prophase 1 of meiosis until ovulation, ovulation occurs finishing meiosis 1, onces a sperm connects with the egg it is then in meiosis 2 creating an egg
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polar bodies
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after meiosis 1 there are four haploid eggs, in cytokinesis all of the cytoplasm goes to one and the others are considered polar bodies
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What are the two groups that never carry out asexual reproduction?
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birds and mammals
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parthenogenesis
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reproduction of only females where the haploid eggs are clones
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What were Mendels inferences about genetics?
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1. the basic units of genetics are material elements 2. these elements come in pairs 3. they retain their formation through many generations 4 pairs separate during gamete seperation
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What species did Mendel work with?
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Pisum Sativum
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What did Mendel do?
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cross pollenated
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Phenotype
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physical feature of an organism
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genotype
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genetic makeup
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parental generation
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makes offspring called first filial generation
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allel
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alternate forms of genes
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F1 Generation
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all yellow
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F2 Generation
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mixture
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F3 Generation
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some all yellow and some mixed
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Mendels First Law
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Law of Segregation: differing characteristics in organisms result from two allels that seprate in gamete formation so the gametes get one of the two allels
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monohybrid cross
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when breeding is done with only one difference
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dihybrid cross
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breeding is done with two characteristics
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In a dihybrid cross, what is the ratio outcome?
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9:3:3:1
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Mendels Second Law
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Law of Independent Assortment: during gamete formation, gene pairs assort independently
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incomplete dominance
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a genetic condition in which heterozygus phenotypes is intermediate between either homozygus phenotypes (1:2:1)
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codominance
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a condition in which two allels of a given gene have different phenotype effects, with both effects manifesting in organisms that are heterozygus for the gene
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multipule allels
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three or more of the same gene exsist in a population
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polygenic inheritance
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the inheritance of a genetic character that is determined by the interaction of multipul genes
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bell shape
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meaning the distribution of values that is symmetrical and largest around the average
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pleitrophy
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a single gene has many effects
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What is an example of pleitrophy?
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fragile X
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hemophilia
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failure of the blood to clot properly
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Name some X linked disorders
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hemophiliac, duchenne muscular dystrophy, color vision
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recessive disorder
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a disorder that will not exsist in the presence of a functional allel
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Why are recessive disorders found mostly in men?
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because there is not a backup allel on the extra X as women have
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Autosomal Recessive Disorders
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recessive disfunction that is found on an autosome
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Name some examples of autosomal recessive disorders
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albinism, sickle cell anemia, cyctic fibrosis, phenylketonuria, tay sachs disease, werner syndrome
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Name examples of autosomal dominant disorders
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huntington disease, marfan syndrome, polydactyly
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polyploidy
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a condition where one or more sets of chromosomes have been added to the genome of a diploid organism
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aneuploidy
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an organism has either gained or lost a single chromosome
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What is an outcome of aneuploidy?
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miscarriage or down syndrome
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nondisjunction
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brings aneuploidy, it’s a failure of homologous chromosomes to separate during meiosis
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Down Syndrome
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a case where a child has three copies of chromosome 21
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Turners Syndrome
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present when girls have only one X chromosome
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Klinefelter Syndrome
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XXY, found in men
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What is aneuploidy in cells that don't effect all of the body?
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cancer
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Where are oocytes located?
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in the overaries surrounded by follicles (fluids that nurture it)
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Name the coarse of semen
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form in the testes, epididymis, vas deferens, urethra
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Where do sperm and egg meet?
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in the uterine tube
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Name the different stages of ovarian follicles
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primary follicals, secondary follicals, tertiary follicals (found in the ovary at this point)
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What does the follicle become once it releases the egg?
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corpus luteum (secretes hormones that prepare the body for pregnancy)
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atresia
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the degradation of follicles
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gonadotropin releasing hormone
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the brain (hypothalamus) releases this
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Name two gonadotropin hormones
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follicle stimulating hormone and lutenizing hormone
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What are the FS and LH released by?
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pituitary gland
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FHS
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promotes development of follicles
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LH
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stimulates the release of estrogen by the follicles
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Estrogen in the ovarian cycle
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controlling growth of the endometrium and controlling the release of LH FHS
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When does estrogen increase LH and FHS?
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when the egg pops out of the ovary
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Corpus Luteum
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releases progestrone
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What happens to the levels of LH and FHS when theres no baby?
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they are decreased
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seminiferous tubes
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the site where sperm is produced; tight tubules
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leydig cells
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cells that produce testosterone found outside of the epidydimus
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Spermatocytes
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cells from which sperm develops
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spermatogonia
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lead to primary and secondary sperm
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When does sperm become mobile?
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when the seminal vesicles mixes them with ejaculation
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prostate gland
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controls traffic out of the penis
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What glands make up semen?
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seminal vesicles, prostate, bulburethral
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acrosome
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enzymes on the sperm that are secreted to kill accessory cells around the egg
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How are late comers kept out?
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once the sperm is united with the egg, the egg releases granuals that harden the outside of the egg
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