BIOL207 Chapter Notes - Chapter 13: Somatic Cell, Birthmark, Wild Type

86 views3 pages

goldleopard391

8 Nov 2016

School

University of Alberta

Department

Biology (Biological Sciences)

Course

BIOL207

Professor

Kirst King- Jones

For unlimited access to Textbook Notes, a Class+ subscription is required.

Document Summary

Chapter 13 alleles at a single locus. A section of the chromosome is called loci. Since somatic cells form the tissues of the organisms and are not passed down as alleles are defined as mutant, wild type or variant. The complete set of alleles is called the genotype. The visible/detectable affects that the alleles have on that individual are called the phenotype. If the two alleles are present in an individual (like in a diploid cell) the interaction between them might influence their expression in the phenotype. Somatic cells- cells, which form the body cells. Germline cells- cells that form gametes for the next generation gametes, any mutations in the somatic cells will only affect the individual they occur in and will not occur in the offspring. The germline cells however, are passed down on to the next generation of gametes and will affect the offspring not the individual carrying the mutation.

Related Questions

1. Haploid Saccharomyces cerevisiae yeast cells contain the following alleles at the MAT locus.

a. Allele a

b. Allele alpha

c. Allele a or alpha

d. Alleles a and alpha

2. The following statements are true for the Saccharomyces cerevisiae yeast, except __________.

a. Yeast mating type a produces a-factor.

b. Yeast mating type alpha produces alpha-factor.

c. a-factor or alpha-factor signals the presence of a yeast cell to the neighboring cells.

d. Yeast mating type a-cell responds to a-factor, alpha-cell responds to alpha-factor.

3. A yeast strain can sexually conjugate with another yeast strain of the same mating type.

a. True

b. False

4.Heterothallic Saccharomyces cerevisiae yeast strains commonly used in controlled experiments are haploid, with either mating type a or alpha.

a. True

b. False

5. Complementation test is used to ____________________________.

a. determine the mating type of yeast.

b. determine whether mutations occur at the same gene or different genes.

c. identify mutant organisms.

d. determine functional relationships between genes.

6. Yeast cells with mating type alpha can sexually conjugate with yeast _________.

a. mating type a

b. mating type alpha

c. allele a or alpha

d. alleles a and alpha

7. Complementation test is conducted by ___________ two strains of organisms with different mutations.

a. isolating

b. morphologically identifying

c. growing

d. intercrossing

8. Assuming alleles B or b are found in locus 1; alleles C or c are found in locus 2. Which of the yeast strains below contains recessive mutations at loci 1 and 2?

a. Yeast strain with alleles B and C

b. Yeast strain with alleles B and b

c. Yeast strain with alleles C and c

d. Yeast strain with alleles b and c

9. When mutations occur at different genes, two strains of yeast are considered to be not complement.

a. True

b. False

10. Yeast cells that are ready to mate will produce a mating projecting called _______ to form a pear-shape cell.

a. pilus

b. yeast ring

c. shmoo

d. spore

apricotcrocodile918

Ploidy refers to the number of complete sets of chromosomes (genes) present in a cell. The number of chromosomes in a complete set is a fixed characteristic of a species. Humans are diploid with two sets of 23 chromosomes. Fruit flies are diploid with two sets of 4 chromosomes. Sexually reproducing organisms are diploid, each somatic cell of an organism has two complete sets ("di" is a prefix indicating 2.). To complete a life cycle and reproduce new members of a species, mating is required. Mating brings a donation from a male and a donation from a female together. However, if the male and female cells remain diploid, the fertilization will result in a tetraploid zygote. In general, these are not viable. A mechanism is needed to form special haploid cells, gametes. The diploid set is split precisely into two complete haploid sets. That mechanism is meiosis.

The complete set of chromosomes of a species is also the complete set of genes of a species, the genome. (Yes, there is a minor contribution from mitochondria and chloroplasts. Inheritance of this information is "cytoplasmic".)

Please answer the following questions:

1. How many chromosomes in a brain cell of a fruit fly? How many chromosomes are in a liver cell of a human? Explain both answers.

2. How many chromosomes are in a fruit fly unfertilized egg? How many chromosomes are in a human egg? Explain both answers.

3. Why is meiosis necessary for sexually reproducing organisms? How many chromosomes are in a human zygote? Relate the two answers.

4. What is a gene allele? Suppose there is a gene called "bingo" and it is present once in a complete haploid set. How many alleles of "bingo" does a diploid individual have? How many copies or versions of the gene "bingo" are present in a diploid individual?

5. Modern DNA sequencing clearly identifies alleles by showing the different DNA sequence of each allele. These alleles may be termed structural alleles (I coined the term for this problem.). Classical genetics only dealt with phenotypes or visible traits. As a result, alleles of genes were identified by functionality, usually normal or non-functional. Using your knowledge of gene structure and gene expression, postulate a relationship between structural alleles and functional alleles. (include relative amounts; more, less, or equal).

What is a genome? What is a genome made of? Describe the bacterial genome. How do bacteria reproduce? What is binary fission? Distinguish between a chromosome and chromatin. Where are chromosomes located in eukaryotic cells? What is the chromosome made of? What is a centromere? What is the centromere's role? What are sister chromatids and how do they arise? Distinguish between somatic cells and germ (gametes) cells. Describe the cell cycle. What are the different phases? What occurs during S phase? What is interphase? How is the cell cycle controlled?

Describe mitosis. What are the phases of mitosis? What occurs in each of the phases of mitosis? What is cytokinesis? How does this differ between plant and animal cells? What is a kinetochore? Where does it form? What is its role? What is the role of microtubules in mitosis? What is a centriole and what is it composed of? What is a centrosome and what is its role in mitosis? What is the metaphase plate and why is this important? What is the mitotic spindle, its role and its makeup? What defines a diploid cell? How many copies of each chromosome is in a diploid cell? What about a haploid cell? Why do the daughter cells of mitosis always have the same complement of chromosomes?

Describe meiosis. What are the phases of meiosis? What occurs in each of the phases of meiosis? Distinguish between meiosis I and meiosis II and describe how each of these processes compare to mitosis. Why do animal cells undergo meiosis? What is a gamete? What is a zygote? What are recombination, crossing-over, and chiasma? When and why does this occur? What is meant by 'homologous pair of chromosomes'? Why don't the daughter cells of meiosis have the same genetic makeup? What controls the segregation of chromosomes into the gametes?

What are genetic characters? What are genetic traits? What is an allele? What is a locus? How many alleles at each locus would a human cell have and why? Distinguish between genotype and phenotype. What is meant by a dominant gene? What is meant by a recessive gene? How do these differ? What is the genotype of a homozygous dominant organism? What is its phenotype? What is the genotype of a homozygous recessive organism? What is its phenotype? What is the genotype of a heterozygous organism? What is its phenotype? What is a genetic cross? Distinguish between the P, F1, and F2 generations. What is a true-breeding line? What is the genotype and phenotype of a cross between homozygous dominant and homozygous recessive parents? If the F1 progeny are crossed, what would be the genotype and phenotype of the F2 generation? What would be the phenotypic ratio? What would be the genotypic ratio? Be ready to generate Punnet square tests or probability analyses of crosses involving more than one genetic locus. Describe a dihybrid cross where two alleles are homozygous dominant in one parent and homozygous recessive in the other. What would be the phenotypic ratio of the F2 generation from this dihybrid cross? What is meant by independent assortment? Be prepared to calculate probabilities resulting from different crosses.

Distinguish between complete and incomplete dominance. How would incomplete dominance alter the results of a hybrid cross? What would the resulting F2 generation phenotype and genotype ratios be? What is codominance? How does this affect the results of crosses? Be prepared to determine likely blood types of parents based on the blood types of their offspring. What is a polygenic trait? What is a carrier state for a genetic disease? What is meant by linked genes? How does this affect expected outcomes of genetic crosses? How is gene linkage used for chromosomal mapping? Distinguish between autosomes and sex chromosomes. What sex chromosomes are found in women? What sex chromosomes are found in men? What are sex-linked traits? Be prepared to give the results of crosses that involve sex-linked recessive traits. What is the process of nondisjunction? What are the likely results? Why is this important? What is a Barr body? Recognize the genetic abnormality of Downs Syndrome, Turner's Syndrome, and Klinefelter's Syndrome.

pucewallaby221

BIOL207 Chapter Notes - Chapter 13: Somatic Cell, Birthmark, Wild Type

Document Summary

Get access

Related Documents

BIOL207 Chapter Notes - Chapter 16: Heredity, Punnett Square, Classical Genetics

BIOL207 Lecture Notes - Lecture 16: Gamete, Achondroplasia, Sperm Bank

BIOL207 Lecture Notes - Lecture 4: Punnett Square, Gamete, Mendelian Inheritance

Related Questions