| A | B |
|---|
| chromosomes | rodlike structures that contain gentic material; exists in pairs; thickened chromatin; coiled DNA and its proteins |
| chromatin | genetic material in a threadlike appearance; made up of DNA and protein; found in thenuclues; condense and thicken to form chromosomes |
| chromatid | 2 identical partso f a chromosome that are held togther by a centromere; ensures each cell wil have the same genetic info after mitosis |
| centromere | holds 2 identical parts of a chromatid together to form a chromosome |
| kinetochore | place on centromere where spindle fibers attach to provide a pathway for chromosomes to travel |
| centrosome | small round area outside nuclues that contain centrioles |
| centriole | help form spindle fibers |
| histone | chromosomal DNA coils around these proteins |
| nucleosomes | bead-like structure formed by DNA and histone molecules; interact w/ each other to forma thick fber that is shortened by loops and coils-tightly pacekd chromosome |
| mitosis | cell division for the purpose of producing 2 identical daughter cells-2 diploid chromsome # cells; division of chormosomes into 2 identical sets |
| meiosis | cell division for purpose of producing 4 cells w 1/2 the original chromosome # |
| The cell cycle includes: | cell grows, prepares for division, division to form 2 daughter cells, begin cycle again |
| The mitosis process is triggered by | surface area/volume ratio and nucleus control of determined amt. of space |
| The 3 steps of mitosis: | Interphase, M phase (mitosis phase), Cytokinesis |
| 3 steps of interphase | G1 (Gap 1) phase; S phase (DNA synthesis); G2 phase (Gap 2) |
| Interphase is characterized by | a great deal of growth |
| Occurs in G1 phase | cellular growth/development |
| G1 is the stage between | cell division |
| In G1, the nuclear membrane is | present |
| The cell is in the ____ phase the majority of the time. | G1 |
| In G1, the DNA nucleus is in the form of | chromatin |
| Once the brain has fully formed, the nerve cells do not divide again and are stuck in | G1 |
| Occurs in S phase | DNA copied in chromatin; protein synthesized |
| Animals cells have _______. | centrosomes |
| G2 prepares for | mitosis |
| Occurs in G2 | mitochondria and other organelles replicate; microtubules (protein fibers) prepare to form spindles |
| ____ occurs during the M phase | mitosis |
| During mitosis, | the nucleus of a cell divides and produces 2 nuclei and same no. and type of chromosomes |
| 4 steps of M phase | Prophase, Metaphase, Anaphase, Telophase |
| Prophase is the ____ phase | longest |
| 4 things in prophase: | 1) chromosomes condense to become visible and nucleolus diappears 2)nuclear membrane broken down by enzymes; 3)Astral rays of microtubules form a round centriole-centrioles separate to poles-create equator and form spindle fibers 4) chromosomes attach to the spindles |
| Metaphase is the ____ phase | shortest |
| 4 things in metaphase: | 1) chormosomes line up on equator; 2)microtubules on kinetichore gorw until reach pole of spindle fibers; centrosome/kinetochore attaches to individual spindle fibers; 4)centromere of each chromosome attaches to poles of spindle |
| In Anaphase, | cnetromere divides and 2 chromatids/chromasomes separate into pairs and move to opp. poles along spindle fibers; now 2 identical sets of chromosomes at opp. poles |
| 4 things in telophase: | 1) nuclear membrane forms around each pole of chromosome 2) nucleolus appears 3) chromosome uncoils becoming chromatin 4) spindle fibers disappear |
| 2 things in cytokinesis: | 1) cyoplasm splits in half at the equator 2) each half has a nuclei and organelles from G2 interphase |
| In animal cell cytokinesis: | cell membrane pincehs in half and divides |
| In plant cell cytokinesis: | cell plate develops betwn. 2 daughtere cells and later forms a cell wall |
| RBCs, unlike the nerve cells of the brain, | continue cell cycle throughout life |
| meiosis- | cell division for the purpose of producing 4 haploid chromosome # cells; results in production of gametes |
| Chromosomes occur in | pairs |
| The chromosome _____ defines the species | number |
| 2 chromsomes of each pair have ther genes aligned identically and are called _____ chromosomes | homologous |
| Chromosome carry ____ information | hereditary |
| DNA in chromosomes contain | many genes |
| ___ % of DNA contains gnees; the remaining ____ % tells the genes to activate | 5; 95 |
| monosomy- | fertilization of a gamete that is missing a chromosome (22 chromosome # of gamete) |
| trisomy- | fertilization of a gamete w/ an extra chromosome (24 chromosome # in gamete) |
| Trisomy may result in | Down's syndrome which has an extra copy of chromosome # 21 |
| Disjunction- | spearation of homologous pairs of chromosomes |
| Nondisjunction- | all chromosomes do not separate; results in trisomy; if occurs in autosomes is usually lethal |
| autosomes- | fist 22 pairs of chromsomes, deal with matters other than sex |
| sex chromosomes- | carry genes that determine sex of an individual |
| females only produce __ chromosomes | X |
| Males produce ___ or ___ chromosomes | X or Y |
| ___ responsible for determining sex | male |
| XX means is a | girl |
| XY means is a | boy |
| nondisjunction that has occurred in sex chromosomes may be lethal if it produces a ____ condition | YO |
| Biologists believe that the ____ chromosome is necessary for normal development | X |
| karyotype- | picture of chromosome pairs in cell arranged by size |
| amniocentisis- | amniotic fluid surrounding fetus is collected and a karyotye is done to reveal any abnormalities |
| chorionic villi sampling- | cells from the chorionic villi of placenta are collected for karyotype |
| Two parts of meiosis: | Meiosis 1 and 2 |
| 4 parts of meiosis 1: | Prophase 1; Metaphase 1; Anaphase 1; Telophase 1 |
| 4 parts of meiosis 2: | prophase 2; metaphase 2; anaphase 2; telophase 2 (same as mitosis except chromosomes don't replicate before divide @ centromere) |
| 4 things in prophase 1: | 1) chromatin condenses, shortens, thickens 2)nuclear envelope broken down by enzymes; 3)homologous chromosomes pair up synapse and arms of chromosomes cross over; 4)crossing over produces genetic variation |
| In Meiosis 1, each chromsome finds its homologous chromsome to form a | tetrad |
| When crossing over occurs, it is an exchange of | alils |
| 2 parts of Metaphase 1: | 1) tetrads/homol. chrom. pairs move to equator via spindle fibers; 2)orientation of homologous pairs is random-equation of combinations is 2^n (n=haploid chrom. #) |
| Anaphase 1: | homologous chromosomes separate-not at centromeres like mitosis-and move to opp. poles via spindle fibers; nondisjunction can occur |
| If all chromsosmes don't separate in anaphase, could result in | trisomy or monosomy |
| 3 parts Telophase 1: | 1) chromosome at opp. poles 2) 2 daughter cells with (n) chromos. # 3)cytoplasm divides |
| Prophase 2: | 2 chromatids attached at centromere |
| Metaphase 2: | chromosomes line up at equator |
| Anaphase 2: | chromatids of each chromosome separate and move to opposite poles |
| Telophase 2: | 4 haploid cells formed |
| _____ are sometimes the key element in allowing an organism to evolve. | mutations |
| deletion- | fragment of chromosomes is lost, therefore sets of genes are missing in the cell |
| duplication- | fragment is copied and the chromsome then carries 2 copies of the same gene |
| inversion- | fragment separates and rejoins original chromosome in opposite direction; genes have changed locations |
| translocation- | fragment of chromosome joins a different chromosome |
| amino acid- | 20 diff. amino acids made up of O, C, H, N, and S; chains of these make up proteins |
| peptide- | covalent bond that joins a.a. together |
| proteins- | polymer/polypeptide of a.a.; biochemical pathways that direct synthesis of lipids, carbs, and nucleotides; responsible for cell structure and movement |
| nucleic acid- | deals w/ heredity; 2 types |
| genetic code- | code for formation of proteins, a sequence of nitrogenous base codes |
| gene expression- | process of reading info from DNA to form proteins; has 2 stages-transcription and translation |
| DNA- | (deoxyribonucleic acid) contains genetic info needed to form and control physical makeup and chemical processes of an organisms; contains the sugar deoxyribose, contains code for protein formation; twisted double helix/ladder; found in nucleus and mitochondria |
| nucleotide- | fundamental basic unit of a nucleic acid, consists of a phosphate group, a ribose sugar, and a nitrogenous base |
| triplet code- | 3 nucleotides on DNA that code for a specific a.a., 64 different triangles |
| nitrogenous base- | makeup the rungs of the DNA ladder; 2 groups; purines and pyrimidines |
| purines- | 2 of 4 bases of DNA-cytosine and thymine; has 2 ring |
| replication/DNA synthesis- | DNA's ability to make an exact copy of itself |
| RNA- | (ribonucleic acid) implements DNA genetic code and therefore protein synthesis; single stranded; sugar is ribose which has 2 more O than deoxyribose; found in nucleus but can travel to the cytoplasm |
| mRNA- | (messenger RNA) brings genetic message/info from DNA in nucleus to ribosomes in cytoplasm |
| tRNA- | (transfer RNA) carries a.a. from cytoplasm to ribosomes; single strand of RNA that loops back on itself (like a clover leaf); found in the cytoplasm |
| rRNA- | (ribsomal RNA) found only int he ribosomes of which it is a major part |
| codon- | 3 nucleotide combinations on mRNA that specify a particular a.a.; 64 codons; 61 specify an a.a.; 3 are stop codons |
| initiator/start codon- | serves as a starter sequence for the synthesis of a protein (AUG) |
| stop codon- | signals the end of the polypeptide (UAA, UAG, UGA) |
| RNA polymerase- | works on polymers RNA and DNA; identifies and attaches to promoter on DNA where the separation of DNA double helix occurs until it reaches terminator sequence; speeds up development of mRNA strand |
| transcription- | occurs when a molecule of DNA is copied and forms a complimentary strand of DNA |
| terminator- | stop sequence of DNA for transcription |
| promoter- | sequence of DNA that represents starting place for transcription to begin |
| anticodon- | tRNA's 3 nuclotide sequence that is complimentary mRNA codon; exists in cytoplasm and can only pick up a.a. specific to its nitrogenous base sequence |
| translation- | decoding of mRNA message to polypeptide chain/protein; mRNA gives the info to make the protein directed by DNA |
| DNA is comprised of | a simple Carbon 5 sugar (deoxyribose); a phosphate gourp; a nitrogenous base |
| The DNA is twisted at the | helix |
| The sides of the DNA ladder alternate between | sugar and phosphate groups |
| The bases of DNA meet at the center of the ____ and connect by ____ | rung; hydrogen bonds |
| DNA controls the prouduction of | proteins (a.a. chains) |
| DNA promotes ___ and _____ | growth and healing |
| DNA controls ____ activities | cellular |
| DNA has the ability to _____, which is imperative to production of new cells. | copy itself |
| DNA is found in the | nucleus and mitochondria |
| triplet code- | 3 nucleotides that code for a specific a.a. |
| There are ____ triplet codes | 64 |
| There are ____ a.a. | 20 |
| 3 of the triplet codes are | stop sequences (UAA, UAG, UGA) |
| 1 of the triplet codes is recognized as | an initiator/start codon (AUG) |
| a.a are used to make ____ | proteins |
| a.a. are made up of | O, C, N, S, H |
| Purines have a ______ and consist of ___ and ____ | double carbon ring; adenine; guanine |
| The nitrogenous bases are | purines and pyrimidines |
| pyrimidines have _____ and conisist of ___ and ___ | a single carbon ring; thymine; cytosine |
| DNA replication- | the cell needs a particular protein so DNA splits and produces a complimentary strand just like the one that split |
| 3 steps of DNA replication: | 1)Enzyme that breaks H bonds betwn. bases sep. DNA chains 2) complimentary nucleotide bases from H bonds with comp. base 3)DNA polymerases helps sugars bond to their new prospective neighbor phosphate |
| In transcription, ______ is formed from an unzipped portion of DNA. This is the sequence that will cause | mRNA; the formation of the protein the cell needs |
| In transcription, RNA polymerase binds to the beginning gene at the | DNA promoter sequence |
| In transcription, complimentary RNA nucleotides are added to a traling tail on the _________. This tail is complimetnary to the DNA's sequence that is requesting a protein. | RNA |
| In transcription, ____ nucleotides per sec. are ____ until _____ reaches the terminator DNA sequence. | 60; transcribed; RNA polymerase |
| At the end of transcription, | DNA strand zips back up |
| Translation- | bonding of amino acids to form proteins; the original order of bases in a portion of DNA is translated to order of amino acids in particular protein |
| In translation beginning, ______ leaves the ______ and goes into the ______ and binds to the _______ | mRNA; nuclues; cytoplasm; ribosomes |
| In translation, tRNA exists in the cytoplasm as | 3 nucleotides short strands called anticodons. |
| In translation, an anticodon is specific to one ______. Once the anti codon has found its a.a. it takes it to the ______ to pair up with the ________ | a.a.; ribosomes; complimentary mRNA codon |
| In translation, when a tRNA pairs with its complimentary mRNA codon next to it then the a.a. are joined by _______ bonds. | peptide |
| In translation, once the peptide bond is set the first tRNA is released back into the cytoplasm to find another ____ for future ____ | a.a.; translation |
| The translation cycle contin. until all a.a. have been joined by peptide bonds to form the _____ specified by DNA. | proteins |
| the _______ unzips the DNA on a specific place where instructions for proteins are located. | helicase |
