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12.5 Notes - Trimble County Schools
12.5 Notes - Trimble County Schools

... • Genes- A segment of DNA nucleotides that code for a specific characteristic • Chromosomes – long strands of DNA (46 in humans) • Egg – female gamete • (haploid with 23 chromosomes) ...
7.1 Chromosomes and Phenotype
7.1 Chromosomes and Phenotype

... – They are either recessive or dominant • One recessive disorder is Cystic Fibrosis – Is a disease that causes excessive production of mucus that causes blockage of pancreatic ducts, intestines, and bronchi, it is fatal – A heterozygote for a recessive disorder is a carrier. ...
Introduction to Genetics
Introduction to Genetics

... Metaphase II: • Chromosomes line up across the cell’s center. ...
Study Guide for the LS
Study Guide for the LS

...  alleles: two forms of the same gene (represented by letters such as TT, Tt, or tt) These may be dominant or recessive. Alleles make up your genotype  dominant trait: a trait observed when at least one dominant allele (capital letter) for a characteristic is inherited (for example Rr or RR). When ...
Mitosis Question Sheet
Mitosis Question Sheet

... ...
Planet Earth and Its Environment A 5000
Planet Earth and Its Environment A 5000

...  Repair of damaged tissue and replacement of worn out cells  Genetic stability: mitosis ensures the precise and equal distribution of chromosomes to each daughter nucleus, so that all resulting cells contain the same number and kind of chromosomes as each other and as the original parent.  Asexua ...
Chromosome Theory Sex Chromosomes
Chromosome Theory Sex Chromosomes

... Sex Chromosomes Dosage compensation ensures an equal expression of genes from the sex chromosomes even though females have 2 X chromosomes and males have only 1. In each female cell, 1 X chromosome is inactivated and is highly condensed into a Barr body. Females heterozygous for genes on the X chro ...
Appendix A: Analyzing Chromosomes through Karyotyping
Appendix A: Analyzing Chromosomes through Karyotyping

... chromosome. Those traits coded for by genes on the sex chromosomes are called "sex-linked" traits. Meiosis is the process by which eggs or sperm are produced. In order to keep the chromosome number constant at 46 from generation to generation, each egg or sperm must contain only 23 chromosomes. At f ...
Genes
Genes

... Tay-Sachs Disease: Causes destruction of nervous system, blindness, and death during early childhood. Cystic Fibrosis: Makes breathing and digestion difficult, its caused by abnormal genes, one from each parent. Down Syndrome: Caused by a chromosomal abnormality known as Trisony-21,( the presence of ...
Meiosis Review
Meiosis Review

... 1. This is the generic term for both sperm and eggs. Hint: it starts w/ a G. (gametes) 2. What must happen to a cell’s DNA before it divides? (replication) 3. This is a segment of DNA that codes for an expressed trait. (gene) 4. An average human somatic cell has how many chromosomes? (46) 5. This te ...
Cells
Cells

... A chromosome is composed of a DNA molecule and associated proteins. During normal cell functions, chromosomes exist as single-stranded structures. During cell division, chromosomes consist of two strands of DNA joined at the centromere. Since the DNA molecules have replicated, one strand of a chromo ...
7.1 Chromosomes and Phenotype
7.1 Chromosomes and Phenotype

... The chromosomes on which genes are located can affect the expression of ________. ...
File - Enders Science Page
File - Enders Science Page

... Write the name of the stage of the cell cycle that corresponds to each event described below. 1. Centromeres divide. ________________ 2. Centrioles move to opposite ends of the cell. ________________ 3. Nuclear membranes form around each mass of chromosomes. ________________ 4. Chromosome strands se ...
Meiosis and Genetics Test Review
Meiosis and Genetics Test Review

... Berry, a young starlet. The baby was blood type B, the mother A, and Chaplin O. From what you know about the inheritance of blood types, could Chaplin have been the father of the child? (At the time of the trial, blood group evidence was not admissible in California courts. Charlie Chaplin was decla ...
Sample questions - I Exam
Sample questions - I Exam

... In humans, the ability to taste the chemical phenylthiocarbamide (PTC) is attributed to the dominant allele of a gene, denoted T, located on chromosome 7. The recessive allele of this gene is designated t. Individuals with the genotypes T/T and T/t are tasters of PTC, and those with the genotype t/t ...
Unit 8: Inheritance & Human Genetic Patterns
Unit 8: Inheritance & Human Genetic Patterns

... A group of genes located on one chromosome. These genes are usually inherited together. Example: ...
Chromosomes and Cell Reproduction
Chromosomes and Cell Reproduction

... of genetic information (genes) • Genes = segment of DNA that codes for a protein or RNA molecule • When genes being used, DNA (chromatin – DNA and its associated proteins) is stretched out • Before cell division, DNA must divide and then coil up into chromosomes ...
Chapter 12: Cell ASEXUAL Reproduction (MITOSIS) Section 1
Chapter 12: Cell ASEXUAL Reproduction (MITOSIS) Section 1

... ~90% of the time the cell is in INTERPHASE = cell growth, nuclear envelope is intact, chromatin exists, centrosomes w/microtubules exist. There are 3 points to Interphase: G1 (growth 1), S (DNA synthesis), G2 (growth 2). There are start/stop signals (like red/green lights), at G1 and G2, that tell t ...
Science 7
Science 7

... examines the chromosomes from the cells Can determine whether the baby has the correct number of chromosomes and whether it’s a boy or girl ...
Lesson 12-Mitosis - Northern Highlands
Lesson 12-Mitosis - Northern Highlands

... • Cell division is the process by which this happens! • Cell division results in two cells that are identical to the original parent cell. • All organisms grow and change; worn out tissues are repaired or replaced by newly produced cells! ...
Mitosis: Modeling Cell Division
Mitosis: Modeling Cell Division

... Every cell in your body has the same genetic information (genes). You started out as one cell, but you have grown into trillions of cells. How can that happen? In our model, you start with one cell containing 4 chromosomes and end up with 2 cells, both with 4 chromosomes and both with the same genet ...
UNIT 2: Genetic Processes
UNIT 2: Genetic Processes

... The number of individual chromosomes in each cell varies from one species to the next • Human somatic cells have 46 chromosomes – How many chromosomes are in gametes? ...
word doc
word doc

... Cause: defect version of the gene that codes for a muscle protein. ...
3 - Mitosis activity (recovered)
3 - Mitosis activity (recovered)

... a nuclear membrane forms around each new set of chromosomes (which uncoil into thin chromatin) During cell division (cytokinesis) the cytoplasm pinches off at the centre of the cell to form two cells (like a draw-string on a gym bag). Back to interphase the two new little cells will grow, replicate ...
Human Genetics - Northwest Allen County Schools
Human Genetics - Northwest Allen County Schools

... dense region in the nucleus called a Barr body. This phenomenon can cause interesting traits like the calico color pattern in cats. The genes for the black and orange color are on the X chromosome. ...
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Chromosome



A chromosome (chromo- + -some) is a packaged and organized structure containing most of the DNA of a living organism. It is not usually found on its own, but rather is complexed with many structural proteins called histones as well as associated transcription (copying of genetic sequences) factors and several other macromolecules. Two ""sister"" chromatids (half a chromosome) join together at a protein junction called a centromere. Chromosomes are normally visible under a light microscope only when the cell is undergoing mitosis. Even then, the full chromosome containing both joined sister chromatids becomes visible only during a sequence of mitosis known as metaphase (when chromosomes align together, attached to the mitotic spindle and prepare to divide). This DNA and its associated proteins and macromolecules is collectively known as chromatin, which is further packaged along with its associated molecules into a discrete structure called a nucleosome. Chromatin is present in most cells, with a few exceptions - erythrocytes for example. Occurring only in the nucleus of eukaryotic cells, chromatin composes the vast majority of all DNA, except for a small amount inherited maternally which is found in mitochondria. In prokaryotic cells, chromatin occurs free-floating in cytoplasm, as these cells lack organelles and a defined nucleus. The main information-carrying macromolecule is a single piece of coiled double-stranded DNA, containing many genes, regulatory elements and other noncoding DNA. The DNA-bound macromolecules are proteins, which serve to package the DNA and control its functions. Chromosomes vary widely between different organisms. Some species such as certain bacteria also contain plasmids or other extrachromosomal DNA. These are circular structures in the cytoplasm which contain cellular DNA and play a role in horizontal gene transfer.Compaction of the duplicated chromosomes during cell division (mitosis or meiosis) results either in a four-arm structure (pictured to the right) if the centromere is located in the middle of the chromosome or a two-arm structure if the centromere is located near one of the ends. Chromosomal recombination during meiosis and subsequent sexual reproduction plays a vital role in genetic diversity. If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe and die, or it may unexpectedly evade apoptosis leading to the progression of cancer.In prokaryotes (see nucleoids) and viruses, the DNA is often densely packed and organized. In the case of archaea by homologs to eukaryotic histones, in the case of bacteria by histone-like proteins. Small circular genomes called plasmids are often found in bacteria and also in mitochondria and chloroplasts, reflecting their bacterial origins.
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