Practice Questions Chapter 3

A diploid cell has 14 chromosomes. Answer the following questions about this cell. 1. How many centrosomes are in the cell at metaphase? 2. How many centrioles are in the cell at metaphase? 3. How many centromeres are in the cell at metaphase? 4. How many centrosomes are in the cell at prophase? 5. How many centrioles are in the cell at prophase? 6. How many centromeres are in the cell at prophase?

1. 2 2. 4 3. 14 4. 2 5. 4 6. 14 Cells at prophase and metaphase have 2 centrosomes with 4 total centrioles. A diploid cell at metaphase or prophase would have 14 centromeres.

A diploid cell has 10 chromosomes. Answer the following questions about this cell. 1. How many chromosome pairs are in the cell? 2. Following mitosis how many cells will be produced? 3. How many chromosomes will each cell have after mitosis?

1. 5 2. 2 3. 10 During S phase, each chromosome is duplicated, and these chromosomes are segregated at mitosis, so that each daughter cell has a copy of all the chromosomes. If a cell is diploid, that means it has two copies of each chromosome, so a diploid cell with 10 chromosomes would have 5 pairs of chromosomes, and after mitosis each daughter cell will have the same number of chromosomes as the original cell (10).

Choose true or false for each statement listed below. 1. Chromosomes that are heterozygous for an allele are not homologous. 2. Haploid organisms can have homologous chromosomes. 3. Homologous chromosomes are 99% identical. 4. Homologous chromosomes carry the same types of genes. 5. Homologous chromosomes may contain different alleles of a gene. 6. The physical location of a gene on the chromosome is called its allele.

1. F 2. F 3. T 4. T 5. T 6. F

Choose true or false for each statement listed below. 1. Binary fission is a form of asexual division. 2. After binary fission is completed, two identical cells result. 3. Each cell has two copies of the chromosome following division. 4. Most eukaryotes divide by binary fission. 5. The daughter cells are separated by formation of a septum. 6. A ring of the protein FtsZ forms at the future site of the septum.

1. T 2. T 3. F 4. F 5. T 6. T

Match the type of sex determination with the organism that uses it. 1. The male is the heterogametic sex and Y determines maleness. 2. The X to autosome ratio determines sex. 3. The female is the heterogametic sex. 4. Males are haploid, females are diploid. 5. Environmental conditions determine sex.

1. humans 2. flies 3. birds 4. bees 5. alligators

Morgan knew that female flies have 2 X chromosomes and male flies have one X. He used reciprocal crosses to demonstrate that inheritance of X-linked traits was consistent with these differences. Given the following reciprocal crosses what are the expected phenotypic ratios for the progeny? Xw is the allele for white eyes. Xw+ is the wild type allele for red eyes. Xw+ is dominant to Xw. 1. XwXw crossed with Xw+Y 1/2 white males 2. Xw+ Xw+ crossed with XwY

1/2 red females all red progeny

A red-eyed female is mated to a white-eyed male. What percentage of the male progeny have red eyes if the parental female was homozygous? Multiple Choice 100% 25% 0% 50%

100%

Describe chromosome number in meiosis II in humans. Multiple Choice 4N -> 2N 2N -> 2N 2N -> 1N 1N -> 2N 1N -> 1N

1N -> 1N

Arrange the following events in the proper order in which they occur during meiosis I. 1 = Separation of homologous chromosomes 2 = Synapsis 3 = Crossing-over 4 = Independent assortment Multiple Choice 1, 2, 3, 4 1, 3, 2, 4 2, 3, 1, 4 2, 3, 4, 1

2, 3, 4, 1

How many chromosomes are present in a human primary oocyte? How many chromatids? Multiple Choice 23; 46 23; 23 46; 46 46; 92

46; 92

A red-eyed female is mated to a white-eyed male. What percentage of the male progeny have red eyes if the parental female was heterozygous (XW+XW)? Multiple Choice 50% 25% 0% 100%

50%

u have set up a mating between white-eyed male and wild-type female flies. The F1 progeny consist entirely of red-eyed males and red-eyed females, which are allowed to mate with each other. Predict the phenotype(s) of the F2 progeny. Multiple Choice All red-eyed females; white and red-eyed males in equal proportions. Red-eyed and white progeny in a 3:1 ratio for both sexes. White-eyed and red progeny in a 3:1 ratio for both sexes. Red and white-eyed females in equal proportions; red and white-eyed males in equal proportions.

All red-eyed females; white and red-eyed males in equal proportions.

Which principles are part of the chromosome theory of inheritance? (check all that apply) Check All That Apply Chromosomes contain genetic material that is transmitted from parent to offspring. DNA is always the genetic material. The nuclei of most eukaryotic cells contain chromosomes that are found in homologous pairs. Each parent contributes one set of chromosomes to its offspring.

Chromosomes contain genetic material that is transmitted from parent to offspring. The nuclei of most eukaryotic cells contain chromosomes that are found in homologous pairs. Each parent contributes one set of chromosomes to its offspring.

Choose the scenario that is best explained by Mendel's law of segregation. Multiple Choice During meiosis, a rose plant containing a dominant red petal allele and a recessive white petal allele creates gametes in which these alleles are separate. During meiosis, a rose plant that is heterozygous for a red petal gene (white is recessive) and for a uniquely shaped thorn gene (standard thorns are recessive) creates a gamete containing the white petal gene and the uniquely shaped thorn gene (among other gametes). Chromosomes from rose plants are transmitted from parents to offspring.

During meiosis, a rose plant containing a dominant red petal allele and a recessive white petal allele creates gametes in which these alleles are separate.

You have crossed a red-eyed female to a red-eyed male. What outcome from your cross would indicate that the female was heterozygous? Multiple Choice Equal proportions of white-eyed males and red-eyed males. Equal proportions of white-eyed females and red-eyed females. All females with red eyes. Equal proportions of red-eyed males and red-eyed females.

Equal proportions of white-eyed males and red-eyed males.

T or F: Independent assortment occurs in prophase I

F

Which of the following does not occur during prophase of meiosis I? Multiple Choice Synaptonemal complex formation Separation of the homologous chromosomes Chiasma formation Recombination Chromosome condensation

Separation of the homologous chromosomes

_________ is when two _______ fuse with each other in the process of fertilization to begin the life of a new organism. Multiple Choice Gametogenesis; somatic cells Gametogenesis; gametes Sexual reproduction; gametes Sexual reproduction; somatic cells

Sexual reproduction; gametes

T or F: In animals sperm production can be continuous or seasonal.

T

T or F: In animals spermatogenesis usually produces four viable products.

T

T or F: Mitosis and cytoplasmic division result in the formation of two genetically identical cells.

T

Select the true statements about chromosomes (check all that apply). Check All That Apply Each chromosome contains a single gene. In prokaryotic cells the complex between DNA and proteins is known as chromatin. The term chromosome means colored body. Each chromosome contains a very long segment of DNA. Eukaryotic cells have circular chromosomes. Chromosomes are replicated during mitosis.

The term chromosome means colored body. Each chromosome contains a very long segment of DNA.

You have a diploid cell with 6 chromosomes. Which of the following would be true for this cell? Multiple Choice There are 6 chromosomes present at metaphase I. There are 6 centromeres present at metaphase II. There are 12 chromosomes present at G1. There are 12 chromosomes present at anaphase I. There are 12 centromeres present at anaphase I.

There are 6 chromosomes present at metaphase I.

T or F: Egg production in animals and plants is similar because in both cases only one viable product is made

True

T or F: In human females all primary oocytes are produced before birth.

True

T or F: Meiosis in both plants and animals produces haploid products.

True

The division of the cytoplasm is called Multiple Choice synapsis. mitosis. meiosis. cytokinesis

cytokinesis

T or F: Both plants and animals have sporophytic and gametophytic portions of their life cycle.

false

Stages of mitosis

interphase --> prophase --> prometaphase --> metaphase --> anaphase --> telophase --> cytokinesis

cytokinesis: is a division of the cytoplasm and organelles. involves a cleavage furrow in animals. involves binary fission in plants. yields two cells with nuclei.

is a division of the cytoplasm and organelles. Correct involves a cleavage furrow in animals. Correct yields two cells with nuclei

Stages of meisosis 1 Prophase

leptotene --> zygotene --> pachytene --> diplotene --> diakenesis

Centromeres divide in Multiple Choice mitosis and meiosis I. mitosis and meiosis II. meiosis II only. meiosis I and meiosis II. mitosis, meiosis I and meiosis II.

mitosis and meiosis II.

Egg cell formation

primary oocyte --> secondary oocyte and first polar body --> second polar body --> egg cell

What is the correct order of the phases of mitosis? Multiple Choice prophase -> anaphase -> metaphase -> telophase prophase -> metaphase -> anaphase -> telophase prophase -> metaphase -> telophase -> anaphase metaphase -> prophase -> telophase -> anaphase metaphase -> prophase -> anaphase -> telophase

prophase -> metaphase -> anaphase -> telophase

T or F: Pollen grains are made up of a single cell.

true

T or F: DNA replication occurs in mitosis

False

T or F: Germ-line cells are haploid but gametes are diploid.

False

What is the correct order of the phases of the cell cycle? Multiple Choice G1 -> G2 -> S -> M G1 -> G2 -> M -> S G1 -> S -> G2 -> M G1 -> S -> M -> G2 G1 -> M -> G2 -> S

G1 -> S -> G2 -> M

Prokaryotic chromosomes (check all that apply) Check All That Apply are usually circular pieces of DNA. contain many genes. are located in a specific region of the nucleus called the nucleoid. are very large pieces of DNA.

are usually circular pieces of DNA. Correct contain many genes. Correct