Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Biology Exam 4 Study
Biology 101 Exam 4 Study Notes
| Question | Answer |
|---|---|
| Meosis | is a type of nuclear division that reduces the chromosome number from diploid (2N) to haploid (N). |
| What does Meosis produce for animals? | Egg and Sperm. |
| What does Meosis produce in plants? | Spores that undergo Mitosis which produces gametes. |
| When does Meosis occur in fungi? | After zygote formation, adults are haploid. |
| Define haploid - | Having a cell set of unpaired chromosomes |
| Define diploid - | Containing two complete sets of chromosomes |
| Define Homologous Chromosomes - | Pairs of chromosomes. One set is maternal, the other paternal (inherited from mom and dad). Same kind of chromosomes, or look a-likes, contain the same genes for the same traits. |
| How do you determine the number of chromosomes in a cell? | Count the amount of centro meres! |
| What are the stages of Meiosis? | Interphase, Prophase, Metaphase, Anaphase, Telophase 1, Meiosis II, Prophase II, Metaphase II Anaphase II, Telophase |
| What happens in Interphase? | Replication of DNA |
| What happens in Prophase? | Homologous Chromosomes come together and pair-up. They form bivalent or tetrad, which are held together by chiasmata. Spindle formation begins. Nuclear envelope fragments. Centrioles move to the poles. Prophase takes the most time in Meiosis. |
| What is synapses? | The union resulting in bivalents. |
| How many bivalents are in Humans during Prophase? | 23 |
| How many chromatids are in a bivalent? | 4 |
| What does crossing-over refer to? | The exchange of genetic material between non sister chromatids of a bivalent during meosis I. |
| What happens in Metaphase I? | Spindle formation completed. Bivalents lined up along the equilateral plane. Spindle fibers have completed their formation and the orgination of bivalents. |
| What happens in Anaphase I? | Homologous chromosomes move to the poles Centromere remain intact) each chromosome still consist of 2 chromatids Cytokinesis begins |
| What happens in Telaphase I? | - spindle dissolves - nuclear envelope reform - daughter nuclei are haploid - EACH chromosome is STILL duplicated - Cytokinesis results in 2 daughter cells - may be omitted in some species |
| What happens in Interkenesis? | - DNA DOES NOT replicate - otherwise similar to Interphase |
| What happens in Meiosis II? | - may vary considerably between species - similar to mitosis - result in haploid cells which are not identical to the parent cell |
| Genetic Recombination - | when DNA contains genes from more than one source, example - crossing-over. |
| What happens in Prophase II? | - chromosomes still duplicated - spindle formation begins - nuclear envelope fragments |
| What happens in Metaphase II? | - spindle formation completed - chromosomes lined up along equatorial plane |
| What happens in Anaphase II? | - chromatids move toward the poles - cytokinesis begins |
| What happens in Telaphase II? | nuclear envelope reforms - chromatids chromatin - cytokinesis is completed resulting in 4 dissimilar haploid cells |
| Somatic Cells - | all the cells of the body except the sex cells (egg and sperm). These cells undergo mitosis. |
| Germ Cells - | sex cells (= egg and sperm). These cells undergo meiosis. |
| Oogenesis - | Meisos in women. Occurs in ovaries. |
| Spermatogenesis - | Meisos in males. Occurs in the testes. |
| Zygote - | Fertilized egg. Result of egg and sperm together. |
| Independent assortment of chromosomes - | Takes place in meiosis. Chromosomes are distributed to daughter cells in various combinations. |
| How are daughter chromosome combinations calculated, how many are in humans? | 2^n, 2^23 = 8,388,608. |
| Spermatogenesis | Primary spermatocyte undergoes Meiosis I and produces two secondary spermatocytes, which undergo Meiosis II producing four spermatids. Spermatids then need to have tails added to become sperm. Begins in puberty of males, and ends when they die. |
| Oogenesis - | Primary Oocyte begins in Meiosis 1. When puberty occurs, one oocyte each month will start meiosis to produce a secondary oocyte and a polar body. The process repeats, creating an ootid, which doesn't continue into metaphse II until fertilizatoin. |
| Summarize Women Eggs - | A women at birth has all the eggs already produced that see will ever have. The eggs are produced when she was an embryo and total 2 to 7 million at birth. When the women reaches puberty only 4,000 of the eggs remain. During her lifetime she will ovulate |
| Mutation - | change in the composition of DNA. The change can be either chromosomal (number of chromosomes) or genetic alteration (change in nitrogen bases - A, T. C, or G) |
| Monosomy - | individual has only one of a particular type of chromosome (2N-1). Example - Turner Syndrome (XO) |
| Trisomy - | individual has more than 2 of a particular type of chromosome (2N + 1). |
| Polyploids - | have more than two sets of chromosomes - Triploids: 3N - Tetraploids: 4N - Pentaploids: 5N |
| What will cause chromosomes to break? | radiation, certain organic chemicals, viruses |
| What will cause changes in chromosomal structure? | Inversion, Translocation, Deletion, Duplication |
| Inversion - | when a segment of a chromosome is turned around 180 degrees, may lead to alter gene activity. |
| Transloaction - | movement of a chromosomal segment from one chromosome to another nonhomologous chromosome resulting in reduced fertility. |
| Deletion - | end of a chromosome breaks off, two simultaneous breaks lead to a loss of a segment. |
| Duplication - | doubling of a chromosomal segment. Human Genetics |
| Karyotype - | is used to look for genetic disorders in humans. Chromosomes are arranged in pairs according to their size, shape and general appearance in mitotic metaphase. |
| Sex Chromosomes - | are the X and Y chromosomes. Females have two X's and males have one X and one Y. |
| Autosomes - | are all other pairs of chromosomes (except X and Y). |
| Nondisjunction - | a member of the homologous chromosome pair fails to separate during Meiosis I or during Meiosis II when chromosome fails to separate into chromatids. The result is either an extra chromosome (N + 1) or a missing chromosome (N - 1). |
| Down Syndrome - | Occurs in 1 in 800. Results from extra 21st chromosome. 23% due to males chromosome donation. 72% due to females chromosome donation. 5% due to translocation. People with down syndrome have wide round faces, slanted eyelids, retarded, large tongu |
| XYY Males (Jacob's Syndrome) - | Males which are taller than average, have persistent acne and tend to have barely normal intelligence. Often with speech and reading problems. Result from nondisjunction during spermatogenesis. Many live normal lives. |
| Turner Syndrome - | Sterile females. Ovaries never develop. Breasts do not develop correctly. |
| Klienfelter Syndrome - | Sterile Males testes do not develope No facial hair Large hands, large feet, long arms and legs |
| Metafemale - | Females with an extra X. They have menstrual irregularities and limited fertility. Usually not mentally retarded. Tend to be tall. More X's you have the greater the chance for being mentally retarded. |
| 3 Ways to detect Genetic Disorders | Amniocentesis, Chorionic villi sampling, Laparoscope. |
| Amniocentesis - | a small amount of amniotic fluid along with fetal cells are required to run an amniocentesis. They are removed from the uterus using a long needle inserted through the abdominal and uterine walls between the 14th and 17th week of pregnancy. |
| Chorionic villi sampling - | cells can be obtained as early as the fifth week after fertilization. Cells obtained from between the uterus and chorion using a thin needle inserted through the vagina. Cells do not have to be cultured and can be tested immediately. |
| Laparoscope - | a devise used to obtain eggs from the female for genetic and biochemical testing prior to pregnancy. |
| Define heredity - | The stability and variation between generations of organisms. |
| Gregor Mendel - | Regarded as the father of genetics. |
| Monohybrid Cross - | a cross in which only one characteristic (trait) is studied. |
| P Generation - | these are the parents in a genetic problem. |
| F1 generation (filial) - | these are the children of the parents (P generation) |
| F2 generation - | these are the children of the F1's or grandkids of the parents |
| Recipricol Cross - | Genetics are identical, except the gender is switched. |
| Mendel's Law of Segregation - | each organism contains 2 factors (genes - during Medels time they did not know what genes where) for each trait and the factors segregate during the formation of gametes so that each gamete contains only one factor for each trait. |
| Mendel's Law of Independent Assortment of Chromosomes - | states that allele pairs separate independently during the formation of gametes.This means that traits are transmitted to offspring independently of one another. |
| Allels - | alternate form of a gene |
| Dominant Allelle - | when present it will be expressed. Represented by uppercase (Capital) letter. |
| Recessive Allele - | need one from each parent in order to be expressed. Represented by lower case (small) letter. |
| Gene Locus - | Where the gene is located |
| Homozygous - | Organism has two identical alleles. |
| Heterozygous - | Organism has two different alleles. |
| Genotype - | Alleles an individual receives at fertilization. Usually indicated as letters TT=Homozygous dominant Tt=Heterozygou Dominant tt=homozygous recessive |
| Phenotype - | Physical Appearance of an individual. |
| What are the geno and phenotypes of the following cross? E= Unattatched earlope, e=attatched earlobe. (EE) Mother X ee (father) | Genotypes = 4 Ee Phenotypes = All heterozygous dominant unattatched ear lobe |
| Punnett Square - | Introduced by a poultry geneticist, R.C. Punnett. Is a table to show possible phenotype/genotype combinations. |
| Dihybrid Cross | Two genetic traits are crossed. |
| Incomplete Dominance - | a pattern of inheritance in which the offspring show characteristics intermediate between two extreme parental characteristics. |
| Codominance - | a condition in heredity in which both alleles in the gene pair of an organism are expressed. Seen in human blood types! |
| Pleiotrophy - | a gene that affects more than one phenotypic characteristic. example - Marfan syndrome - tall, long legs and long arms, long fingers, near sighted, and then to have weak aorta's. |
| Epistasis | genes interact to produce the phenotype, recessive pair of alleles at one locus prevents expression of a dominant allele at another locus. example - albinism in humans - one gene produces pigment, but a different gene controls pigment distribution |
| Multiple Alleles | more than two alleles for a given chromosomal locus example - Rabbits = 4 alleles for coat color |
| Does Environment play a role in determining a phenotype? | Yes |
| Polygenic Inheritance - | when one trait is governed by several genes occupying different loci on the same homologous pair of chromosomes or different homologous pairs of chromosomes. A bell shape curve due environmental effects, each allele has the same degree of influence. |
| Name some examples of Polygenic Inheritance - | Skin Color, Height, Weight |
| Chromosome Theory of Inheritence - | The theory states genes are located on the chromosomes. |
| Who developed the Chromosome Theory of Inheritance? | Theodor Boveri and Walter S. Sutton. |
| What confirms the Chromosome Theory of Inheritence? | 1. chromosomes and genes paired in diploid cells 2. homologous chromosomes and alleles separate during meiosis - haploid gametes 3. separation is independent - all combinations possible 4. Fertilization restores diploid numbers |
| What determines Gender? | Sex Chromosomes |
| Autosomes - | Nonsex chromosomes |
| XX chromosomes are | Female |
| XY chromosomes are | Male |
| What part of a chromosome is the 'sex determining region?' | Y |
| What is the X chromosome? | Chromosome carries genes called sex-linked alleles |
| Linkage Group | A group of genes found on the same chromosome. Example - Eye color, wing type, body color, |
| Recombinant DNA | DNA that contains genes from more than one source. |
| Autosomal Dominant Disorder Examples | Polydactyly, Huntington Disease, Chronic Simple Glaucoma |
| Polydactyly | Extra fingers or toes |
| Huntington Disease | Progressive nervous system degeneration |
| Chronic Simple Glaucoma - | build up of pressure in the anterior chamber of the eye. Can lead to blindness. |
| Autosomal Recessive Disorder Examples - | Cystic Fibrosis, Phenylketonuria, Tay-Sachs Disease |
| Cystic Fibrosis | Affects mucus and sweat glands |
| Phenylketonuria | Essential liver enzyme deficiency |
| Tay-Sachs disease | lysosomal storage disease leading to nervous system destruction |
| Incomplete Dominance Disorder Examples | Sickle Cell Disease |
| Sickle Cell Disease | Cells are generally shaped like sickles, can be painful. |
| Are there any advantages to those with sickle cell? If so, explain. | Yes, in malaria infested regions of Africa, sickle-cell trait infants have a better chance of survival than normal infants (or those with the disease). |
| Sex-linked Trait Disorders | Color blindness, Hemophilia, Muscular Dystrophy, Spinal Ataxia |
| Color Blindness - | inability to distinguish certain colors apart |
| Hemophilia - | Defect in blood clotting mechanism |
| Muscular dystrophy - | Progressive wasting of muscle |
| Spinal Ataxia - | Spinal cord degeneration |
| Friedrich Miescher - | 1869, removed nuclei from pus cells. |
| Edwin Chargaff | 1940's, analyzed in detail the base content of DNA. It was already known that the nitrogen bases were divided into 2 groups: purine bases and pyrimidine bases. |
| Purine Bases: | Adenine and Guanine |
| Pyrimidine Bases | thymine and Cytosine |
| Chargaff's Rule | 1. The amount of A, T, G, and C in DNA varies from species to species. 2. Amounts of A = T and amount of G = C. |
| Rosalind Franklin and M.H.F. Wilkins showed that DNA - | Was in a helix shape |
| James Watson and Francis H. C. Crick corected Franklin and Wilkins and claimed that DNA was a | Double Helix |
| The Double Helix Model of DNA | is like a twisted ladder, sugar-phoshate backbones make up the sides, and hydrogen- bonded nitrogen bases make up the rungs, or steps, of the ladder |
| DNA Replication | The process of copying DNA molecules Is semiconservative |
| What are the 3 steps in DNA Replication | Unwinding, Complementary base pairing, Joining |
| Unwinding - | enzyme helicase unwinds H bonds between the nitrogen base pairs in DNA |
| Complementary base pairing - | DNA polymerase enzyme adds nitrogen bases to the bases on the old strands exposed by helicase. For DNA, A bind with T and C binds with G. |
| Joining - | DNA polymerase enzyme join the nitrogen bases so that the new DNA is composed of a new strand with and old strand. |
| Gene - | is a segment of DNA that specifies the sequence of amino acids in a polypeptide of a protein. |
| Polypeptide - | chain of many amino acids joined by a peptide bond. |
| Protein - | may contain more than one polypeptide chain. |
| One gene - One polypeptide Hypothesis - | each gene specifies one polypeptide of a protein. |
| Protein Synthesis | DNA ->->-transcription->->-> mRNA ->->->translation->->-> Protein |
| Transcription | the process by which a mRNA copy is made from a portion of DNA. |
| Translation | the process by which a mRNA transcript determines the sequence of amino acids in a polypeptide. |
| RNA Base Pairing | C-G A-U |
| Uracil | U, replaces thymine found in DNA |
| Convert this DNA strand to RNA, ATCGGATC | UAGCCUAG |
| Codon | There are 64 possible codons, but only 20 amino acids. The genetic code is redundant. Meaning that several amino acids have more than one code. Codons are sometimes called triplets, since they are based on three nitrogen bases. |
| Polysome - | several ribosomes are often attached to and translating the same mRNA. |
| Frame Shift Mutation - | occur most often because one or more nucleotides are either inserted or deleted from DNA, results can be a completely nonfunctional protein. |
| Point Mutation - | involves a change in a single nucleotide and therefore a change in a specific codon. |
| Cancer - | is a failure in genetic control cells lack differentiation Cells have abnormal nuclei cells form tumors cells angiogenesis and metastasis |
| Metastasis - | Tumor cells move from their place of origion |
| Angiogenesis - | Blood vessels grow into the tumor due to chemicals released by the tumor cell |
| Mutagen | Anthing that causes a mutation |
| Carcinogen | Anything that causes cancer |
| What are some causes of Cancer? | Radiation, Organic Chemicals, Viruses, Tobacco smoke, diet rich in saturated fats low in fiber, Industrial chemicals Heredity Immunodeficiencies (problems with the immune system) |
| Ways to prevent cancer - | 1. Don't smoke 2. Don't sunbathe 3. Avoid alcohol 4. Avoid radiation 5. Be tested for cancer 6. Be aware of occupational hazards 7. Be aware of hormone therapy 8. Right diet a. Avoid obesity b. Lower total fat intake c. Eat high fibe |
| DNA Cloning | multiple copies of a gene or a gene product are made. |
| What are the two methods for DNA Cloning? | Polymerase Chain reation, Recombinant DNA Technology (rDNA) |
| Polymerase Chain Reaction | uses the enzyme DNA polymerase to quickly make multiple copies of a specific piece of DNA. These copies can then be used in DNA fingerprinting. |
| Recombinant DNA Technology | contains DNA from two different sources. This technology is used to make insulin for people who are diabetic. |
| DNA Fingerprinting | the use of DNA fragments resulting from restriction enzyme cleavage to identify particular individuals. |
Created by:
Oni Oceans
Popular Biology sets