BIOL 1001 Chapter : Chapter 10 Lecture Notes

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azuremammoth471

15 Mar 2019

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10. 1 what is the physical basis of inheritance: genes are sequences of nucleotides at specific locations on chromosomes. Inheritance is the process by which the characteristics of individuals are passed to their offspring. A gene is a unit of heredity that encodes information needed to produce proteins, cells, and entire organisms: genes comprise segments of dna ranging from a few hundred to many thousands of nucleotides in length. The location of a gene on a chromosome is called its locus (plural: loci) Homologous chromosomes carry the same kinds of genes for the same characteristics. Genes for the same characteristic are found at the same loci on both homologous chromosomes. Genes for a characteristic found on homologous chromosomes may not be identical. Alternative versions of genes found at the same gene locus are called alleles: mutations are the source of alleles. Alleles arise as mutations in the nucleotide sequence in genes.

Related Questions

Fill in the blank, each word can be used more than once.

word bank- crossing over, avoid predation, reproduce,independent assortment, phenotypes, frequencies, nucleotides,meiosis, protein, prophase, segregation, gene, allele, amino acids,fertilization, arrangement, chromosome.

A(n) _________ is one of multiple forms of the same gene.

These different forms of genes are in the same locus of a(n)_________, but they have slightly different sequences of________.

During ________ I of meiosis, genes of homologous chromosomesalign side-by-side.

Then in a process called _________, homologous chromosomesrandomly line up double-file at the center of the cell and thenseperate. Since alleles are randomly distributed, this processcreates variation among the gametes. After ________ with a gametefrom the other sex, variation among gametes will create variationamong the offspring.

Some offspring will have a more favorable combination of allelesthan others, and will therefore survive and ________ moresuccessfully, leading to more favorable alleles in the nextgeneration. However, sometimes conditions change, andonce-favorable phenotypes may becomes less favorable.

Scientists hope that they will soon be able to use biotechnologyto track the ________ of alleles over multiple generations, therebywatching evolution as it occurs.

taupewolf882

Ants are haplodiploid organisms. This means females are diploid (2n) and males are haploid (n). The gametes produced by both males and females are haploid (n). There is no homologous recombination in males during gamete formation. There is no sex chromosome.

In an ant species, it is known that wings formation (F) and setae density (D) are each controlled by a different, simple-Mendelian locus/gene. Individuals which are homozygous recessive for both genes have no wings (f) and no setae (d). Previous experiments also indicated that both loci/genes are on the same chromosome.

a. Design a test cross to map the genetic distance of the genes, by writing the genotype of the tester and its mate. (2 pts)

Genotype of tester:

Genotype of testerâs mate:

b.In order for the test cross to produce offspring with non-parental phenotypes, the tester has to be of a specific sex. What sex must the tester be? Briefly explain your choice in your own words. (Hint:what is a test cross?) (2 pts)

Sex of tester:

emeraldweasel173

1) Ants are haplodiploid organisms. This means females are diploid (2n) and males are haploid (n). The gametes produced by both males and females are haploid (n). There is no homologous recombination in males during gamete formation. There is no sex chromosome. In an ant species, it is known that wings formation (F) and setae density (D) are each controlled by a different, simple-Mendelian locus/gene. Individuals which are homozygous recessive for both genes have no wings (f) and no setae (d). Previous experiments also indicated that both loci/genes are on the same chromosome.

a. Design a test cross to map the genetic distance of the genes, by writing the genotype of the tester and its mate. (2 pts) Genotype of tester: Genotype of testerâs mate:

b. In order for the test cross to produce offspring with non-parental phenotypes, the tester has to be of a specific sex. What sex must the tester be? Briefly explain your choice in your own words. (Hint: what is a test cross?) (2 pts) Sex of tester:

c. 100 offspring were produced from a particular test cross. The phenotypic ratio of these offspring is observed to be the following:

Normal wings and setae density40

Wings and setae both absent 47

Normal wings but no setae 4

Normal setae density but no wings 9

Calculate and describe in words the genetic distance between the two loci/genes of interest. Remember to include the unit of measurement (6 pts).

carminecaribou726

BIOL 1001 Chapter : Chapter 10 Lecture Notes

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