Term
| ____ ________ and _____ are required for normal growth and development. |
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Definition
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Term
| Mitosis produces new cells and only occurs in what kind of cells? |
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Definition
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Term
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Definition
| cell death that is part of normal development |
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Term
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Definition
| cell death in response to injury |
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Term
| With regards to the cell cycle, what happens during the S phase? G phase? M phase? G1 phase? G2 phase? |
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Definition
S phase - DNA synthesis
G phase - gap for growth
M phase - mitosis (nuclear division)
G1 phase - cell division or cytokinesis
G2 phase - not sure yet |
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Term
| What happens during interphase? |
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Definition
1) Prepares for cell divsion
2) Replicates DNA and subcellular structures
3) Composed of G1, S, and G2
4) Cells may progress to mitosis or enter G0
5) A quiescent phase |
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Term
| Cytokinesis is also known as what? |
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Definition
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Term
| What happens when chromosomes are replicated? |
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Definition
| A process of duplication a chromosome which occurs prior to division. Produces sister chromatids which are held together at the centromere. |
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Term
| What is the end product of mitosis? |
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Definition
| Two identical daughter cells |
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Term
| What four things ultimately happen in mitosis? |
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Definition
1) Replicated chromosomes align
2) Sister chromatids separate and move to opposite poles
3) Nuclear membranes form around each new nucleus
4) Division of cytoplasm or cytokinesis occurs. |
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Term
| Proteins called "__________ ________" monitor progression through the cell cycle. |
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Definition
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Term
| Interphase consists of how many phases and what are they? |
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Definition
G1 - proteins and lipids are produced
G2 - proteins and lipids are produced
S - DNA is replicated |
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Term
| What are three important molecules which help to regulate the cell cycle and what do each of them do? |
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Definition
1) Cyclin - protein responsible for keeping "time" in the cell
2) Cyclin Dependent Kinases - enzyme that acts as an on/off switch for mitosis
3) M-Phase Promoting Factor - protein which starts the M phase. |
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Term
| Telomeres are also referred to as ____. |
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Definition
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Term
| Where are telomeres located? What do they contain? |
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Definition
| At the ends of chromosomes. The contain hundres to thousands of six nucleotide repeats. Most cells lose 50-200 repeats after each cell division. After about 50 divisions, shortened telomeres signal the cell to stop dividing. |
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Term
| what special enzyme prevents the shorteninig of telomeres? Also is said to make a cell line immortal which is sometimes found in cancer cells, sperm, eggs, and bone marrow. |
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Definition
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Term
| Which two types of cells renew tissues? What specifically do they do all of their lives? |
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Definition
1) Stem cells
2) Progenitor cells
They retain the ability to divide and specialize. |
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Term
| What characterizes totipotent? Pluripotent? |
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Definition
Totipotent - Stem cell that can become anything - ES (embryonic stem cell)
Pluripotent - have a potency but not completely potent. This is all that adults have anymore. |
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Term
| What is the end result of meiosis? |
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Definition
| specialized cells that will eventually develop to form gametes. |
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Term
| Meiosis has ___ divisions of the nuclues and produces cells with ____ the number of chromosomes (_______) |
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Definition
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Term
| What is ploidy referring to? What is haploid? What is diploid? |
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Definition
Ploidy is referring to the number of cells.
Haploid - 1N
Diploid - 2N
N refers to the chromosome number |
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Term
| Genetically, what does meiosis intodoce that mitosis does not? |
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Definition
| Meiosis introduces variation. A gene shuffle and the shuffling of chromosomes. |
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Term
| How many chromosome pairs do we have? |
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Definition
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Term
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Definition
Sex cells
For males = sperm
For females = ovum or oocyte |
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Term
| What are homologous chromosomes? When do they pair? What do they form? |
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Definition
Having the same genes in the same order but may carry different alleles, or forms, of the same gene.
They pair during meiosis I and separate in the formation of gametes
Oone copy of each pair is from the mother and ones is from the father. |
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Term
| _______ and ______ ____________ increase genetic diversity in a population. |
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Definition
| Meiosis and sexual reproduction |
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Term
| List 7 things that characterize Mitosis: |
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Definition
1) one division
2) Two daughter cells per cycle
3) Daughter cells genetically identical
4) Chromosome number of daughter cells same as the of parent cell (2N)
5) Occurs in somatic cells
6) Occurs throughout life cycle
7) Use for growth, repair, and asexual reproduction |
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Term
| List 7 things which characterize Meiosis: |
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Definition
1) Two divisions
2) Four daughter cells per cycle
3) Daughter cells genetically different
4) Chromosome number of daughter cells half that of parent cell (1N)
5) Occurs in germline cells
6) In humans, completes after sexual maturity
7) Use for sexual reproduction, producing new gene combinations |
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Term
| Meiosis divides in ___ parts but results in ___ copy of each chromomsome in a gamete. |
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Definition
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Term
| What is the synaptonemal complex? |
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Definition
| Makes sure that the two pairs of chromosomes line up (synapsis) |
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Term
| Is meiosis I haploid or diploid? What is meiosis II? |
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Definition
Meiosis I = diploid
Meiosis II = haploid |
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Term
| When does crossing over or recombination occur? What does crossing over mean? |
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Definition
| Prophase of meiosis I. Crossing over is where Non-sister chromatids of homologous chromosomes (homologs) exchange genes which generates diversity. |
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Term
| Parentals are considered to be ___-___________ while nonparentals are considered to be ____________. |
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Definition
| non-recombinant, recombinant |
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Term
| What happens during Metaphase I of meiosis I? |
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Definition
| Homolog pairs align along the equator of the cell. |
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Term
| What is independent assortment? |
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Definition
| Where the homolog of one chromosome can be inherited with either homolog of a second chromosome. |
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Term
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Definition
| Homologs separate and move to opposite poles. Sister chromatids remain attached at their centromeres. |
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Term
| Telophase I of meiosis I? |
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Definition
1)Nuclear membrane reforms
2)Spindle disapperas
3)Cytokinesis divides cell! |
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Term
| After meiosis I is complete, what comes next? One more time, what is the end result? |
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Definition
| Meiosis II. The end result is four nonidentical haploid daughter cells. Each contains one copy of each chromosome and one allele of each gene which makes each cell unique. |
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Term
| What is the process of spermatogenesis? Mitosis? Meiosis? or Both? |
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Definition
| Stem cells in the testes divide mitotically to produce spermatocytes. Then spermatocytes divide by meiosis to produce four equal sized haploid spermatids which mature into four sperm. |
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Term
| Sperm contain what two vital things? |
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Definition
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Term
| Explain the process of Oogenesis or ovum formation: |
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Definition
1)Cells of the ovary divide to form oocytes
2)Oocytes divide by meiosis
3)Unequal cytoplasmic division
4)A discontinuous process. At birth, oocytes are arrested in prophase I. At ovulation, an oocyte continues to metaphase II.
5)The four meiotic products produce a functional ovum and three polar bodies. |
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Term
| In oogenesis, what is the end product during ovulation? |
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Definition
| 3 polar bodies and 1 functional gamete (ovum) |
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Term
| When does the ovum complete meiosis II? |
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Definition
| After fertilization..YAA SEXY TIME! |
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Term
| What does the sperm contribute to the egg when fertilization occurs? |
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Definition
| The sperm just contriburtes DNA while the egg does the rest. If the mitochondria from the sperm does happen to get inside the ovum, the ovum destroys it. |
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Term
| What is cleavage? What are the cells called and what does the developing embryo become? |
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Definition
| frequent cell division after fertilization. The cells are called blastomeres. The developing embryo becomes a blastocyst which is a hollow ball of cells. |
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Term
| What is signal transduction? |
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Definition
| Process by which cells communicate |
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Term
| The inner cell mass or the blastocyst develops into what? What do the other cells do? |
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Definition
| the embryo. The other cells become the extraembryonic membranes important for implantation and support of embryonic growth. |
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Term
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Definition
When the primary germ layers forms, cells begin to differentiate, and supporting structures form:
-Chorionic villi
-Yolk sac
-Allantois
-By 10 weeks the placenta is fully formed |
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Term
| What are the three germ layers and what are each in charge of? |
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Definition
1) Endoderm - forms most internal organs
2) Mesoderm - muscles and connective tissue
3) Ectoderm - skin, and adrenal glands |
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Term
| What characterizes a dizygotic twin? Monozygotic twin? |
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Definition
Dizygotic Twin - Form from two different zygotes. Two ova are fertilized and there is the same genetic relationship as any siblings.
Monozygotic twins - One ova is fertilized. Developing embryo splits during early development. The twins are genetically identical. |
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Term
| What is the critical period characterized by? |
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Definition
| During the critical period of development, an organ is vulnerable to toxins, viruses, and genetic abnormalities. Altering the normal development may cause birth defects. |
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Term
| Mendel expeirenced in _____ breeding and ___________. |
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Definition
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Term
| Mendel studied what specific plant? |
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Definition
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Term
| What were the 7 traits which mendel studied in pea plants? |
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Definition
1) seed form
2) seed color
3) pod form
4) pod color
5) flower position
6) seed coat color
7) stem length |
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Term
| What is a monohybrid cross? |
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Definition
| When true breeding plants with two forms of a trait are crossed but only one form of the trait shows up. The observed trait is dominant while the masked (hidden) trait is recessive. |
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Term
| The F1 generation of a monohybrid cross tells what? What does the F2 generation tell? |
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Definition
F1 Generation - dominance/recessive
F2 Generation - tells whether haploid or diploid |
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Term
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Definition
| A version of the same gene or DNA sequence but differs in DNA sequence at one or more sites. |
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Term
| Explain Mendel's Law of Segregation: |
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Definition
| Each plant possesses two units (alleles for each trait. Alleles separate in the formaiton of gametes and gametes contain one allele for each trait. |
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Term
| What is genotype? What is phenotype? What is wild type? What is mutant phenotype? |
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Definition
Genotype - The alleles present in an individual - 1) Homozygous - carry the same alleles (TT or tt) 2) Heterozygous - carry different alleles (Tt).
Phenotype - Indicates the trait observed (Tall or short).
Wild Type - Most common phenotype.
Mutant phenotype - a product of a change in the DNA. |
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Term
| What is autosomal inheritance? |
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Definition
| Human autosomal traits which are located on the non sex chromosomes (1-22). They may be inherited as autosomal dominant or autosomal recessive. |
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Term
| What is the meaning of dominance and recessive? |
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Definition
Whether an allele is dominant or recessive is important in determing risk and critical in medical genetics. Reflects the characterisitcs or abundance of a protein.
Recessive tratis have a "loss of function"
Dominant traits have a "gain of function". |
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Term
| What is an autosomal dominant disorder that we talked about in class? |
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Definition
| Huntington's Disease - neurodegenerative. |
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Term
| Autosomal recessive affects who? |
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Definition
| Only homozygous recessive individuals exhibit the affected phenotype. It may skip generations. |
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Term
| Autosomal dominant only affects who? |
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Definition
| Homozygous dominant and heterozygotes. Affected phenotype does not skip generations. |
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Term
| What is a homozygous recessive disease that we talked about in class? |
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Definition
| Cystic Fibrosis. The CTFR gene transports Cl- ions back and forth across membranes to establish water gradients. There is a deffect in this gene which makes less water on one side of the membrane. This can cause organ failure. |
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Term
| How are lethal alleles maintained in a population? |
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Definition
| Recessive traits are maintained in a population in the heterozygotes (Tt). The recessive hides in the population! |
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Term
| What is the main point of mendel's second law of independent assortment? |
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Definition
| The inheritance of one gene does not influence the chance of inheriting the other! Two genes on different chromomsomes segregate their alleles independently. Its random! |
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Term
| The probability of simultaneous independent events is equal to what? |
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Definition
| The product of the probability of each event. |
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Term
| The probability of dependent events is equal to what? |
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Definition
| The sum of probability of each event |
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Term
| What is an important cycle which ends with the production of proteins? |
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Definition
| DNA (genotype) -> mRNA -> Protein (phenotype) |
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Term
| What is multiple alleles? What is an example in humans? |
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Definition
When an individual carries two alleles for each gene. A population can have many alleles within the individual members.
An example in humans is the ABO blood group |
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Term
| What is incomplete dominance? |
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Definition
| When the heterozygous phenotype is distnicn from either homozygous phenotype. It may be an intermediate phenotype. Resembles blending. Intermediate of two phenotypes!!! |
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Term
| What are codominant alleles? |
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Definition
| When both alleles are expressed in the heterozygotes. For blood tyeps, the A and B alleles are codominant. |
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Term
| What are the four blood GROUPS? |
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Definition
1) ABO blood group
2) Rh factor
3) MNS blood group
4) Lewis (Le) |
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Term
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Definition
| When one gene affects the expression of a second gene. |
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Term
| What is Variable Expressivity? |
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Definition
| When a phenotype that varies in intensity. Individuals with the same genotype for cystic fibrosis have varying levels of symptoms. |
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Term
| What is incomplete penetrance? |
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Definition
| When the phenotype is not always observed among individuals carrying the genotype. |
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Term
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Definition
| Extra digits on the hands or feet. |
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Term
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Definition
| When one gene has many symptoms or controls several functions. |
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Term
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Definition
| Appears inherited but is caused by the environment. May have symptoms that resemble an inherited trait or occur within families. |
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Term
| Lastly, what is genetic heterogeneity? |
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Definition
| Where different genes can produce identical phenotypes. Genes may encode for different enzymes in a biochemical pathway. |
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