BIO-105 Module 2 Prework

Select all of the following that result from meiosis in humans.

- Gametes are genetically different from each other and the parent. - Four haploid gametes

Place the following steps in order to describe how DNA is packaged into cells.

1. DNA is wrapped around histone proteins 2. DNA is bundled into structures called nucleosomes 3.DNA is coiled into chromosomes

What is the probability of two parents, genotypes Tt and TT, having an offspring of genotype TT?

2/4

Which of the following best describes incomplete dominance?

A form of inheritance where the heterozygote expresses a phenotype that is an intermediate between the dominant and recessive phenotypes

Which of the following scenarios best describes a codominant form of inheritance?

A white goat is bred with a black goat and the resulting offspring are both white with large black spots.

Which of the following statements best defines sexual reproduction?

Adult humans produce haploid gametes through meiosis.

Variations in eye color, height, blood type, and physiological differences are considered to be the result of differences between the of genes.

Alleles

Variations of a gene are called and include examples such as eye color, blood type, or height.

Alleles

__ are variations of a gene.

Alleles

Which of the following best describes alleles?

Alleles are variations of genes and include examples such as eye color, height, and ability to digest lactose.

Recessive alleles

Are masked by other alleles of that same gene; two are required for phenotypic expression

Select the statements that best describes the relationship between genes and chromosomes.

Chromosomes are composed of long strands of DNA organized into chunks called genes.

Which of the following sentences best summarizes how genes and chromosomes are involved in transmitting information to future generations?

Chromosomes are composed of long strands of DNA organized into genes that code for specific traits. Because genes are inheritable, those specific traits are inheritable also.

Which of the following sentences is true about how DNA is packaged into chromosomes?

DNA is coiled around proteins and organized into bundles before being coiled into a chromosome

Complete the following statement to describe the relationship between genes and chromosomes: Chromosomes are composed of long strands of , organized into that code for specific traits.

DNA, genes

Which of the following best describes the difference between recessive and dominant forms of inheritance?

Dominant alleles mask recessive alleles. So, an individual must have two recessive alleles to express a recessive trait, but only one dominant allele to express a dominant trait.

Which of the following best defines Mendel's law of segregation?

Fertilization results in the production of an individual with two factors for each trait. Each individual has two factors for each trait and produces gametes with one factor for each trait.

Interpret the following scenario to describe one form of non-Mendelian inheritance: A parent with curly hair and a parent with straight hair have a child with wavy hair. Which interpretation is most likely to be accurate?

Hair texture may follow an incomplete dominance form of inheritance.

Select all of the following that display non-Mendelian forms of dominance.

Incomplete dominance — Heterozygous genotypes express an intermediary phenotype that is a blend between dominant and recessive phenotypes. Codominance — Heterozygous genotypes full express both dominant phenotypes.

Dominant alleles

Mask the appearance of other alleles of that same gene; only one is required for phenotypic expression

During the human life cycle, the process of cuts the chromosome number in half in order for fertilization to double the chromosome number.

Meiosis

Which of the following best describes the role of meiosis during sexual reproduction?

Meiosis produces haploid gametes that are genetically different from each other and their parents.

Select all of the following that are stages of meiosis II.

Metaphase II Anaphase II

Bundles of DNA wrapped around histone proteins and then further compressed into euchromatin are called

Nucleosomes

What sentence best defines nucleosomes?

Nucleosomes are small bundles of DNA wrapped around special proteins.

Which statement best describes the inheritance of sickle-cell disease?

Sickle-cell disease is an autosomal recessive disease, meaning it is carried on recessive alleles and requires both diseased alleles in order to be expressed.

Which law states that each individual has two factors for each trait, these factors separate during the formation of gametes, and the resulting gametes have only one factor for each trait?

The law of segregation

In a pedigree displaying a family that carries sickle-cell disease, what would be the expected genotype of affected individuals?

aa

Genes carry instructions for making proteins or other gene products. This means that:

changes in genes can change our physical traits.

During the human life cycle, _____(haploid/diploid) zygotes grow into _____(haploid/diploid) adults through mitosis.

diploid

Alleles that are mask the expression of alleles that are

dominant, recessive

During sexual reproduction, meiosis is responsible for the production of haploid _____(both male and female) that later fuse to form a diploid zygote.

gametes

The basic units of inheritance are called and are carried on chromosomes.

gene

Units called control our physical traits through controlling the manufacturing of proteins and other products.

genes

An individual with the genotype Gg would be considered

heterozygous

An individual with the genotype tt would have two recessive alleles for a trait. Another name for this genotype is

homozygous recessive

During the life cycle of humans, the process of results in haploid gametes and the process of results in diploid adult humans.

meiosis, mitosis

If a phenotypic trait is influenced by several different alleles interacting with each other, it is said to be classified as _____.

multiple allele inheritance

A chart that depicts a family's history in the context of a particular genetic trait is called a(n)

pedigree

Charts that depict a family history of a specific gene trait are called _____.

pedigree

The _____ refers to an organism's physical appearance or characteristics, while the _____ refers to the allele combination it has. Multiple choice question.

phenotype; genotype

The stages of meiosis I in the correct order are

prophase I, metaphase I, anaphase I, and telophase I.

nterpret the following scenario to distinguish between recessive and dominant forms of inheritance. Two unaffected parents that are heterozygous for a genetic disease have a child with the genetic disease. This form of inheritance follows a _____ form of inheritance.

recessive

Chromosomes that exhibit variations due to the sex of an individual are called __ chromosomes.

sex

hromosomes that vary depending on the sex of an individual are called ______chromosomes.

sex

The process where adult humans produce haploid gametes through meiosis is called

sexual reproduction