Genetics 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 (2 at each centrosome). A diploid cell at metaphase or prophase would have 14 centromeres
A diploid cell has 10 total 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
Which of the following accurately reflects the relative chromosome composition at the beginning and end of meiosis II in humans?
1N → 1N
How many chromosomes are present in a human primary oocyte? How many chromatids?
46; 92
Which of the following principles is part of the chromosome theory of inheritance? (Check all that apply.)
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.
Chromosomes that are heterozygous for an allele are not homologous T/F
F
DNA replication occurs in mitosis. T/F
F
Each cell has two copies of the chromosome following division T/F
F
Germ-line cells are haploid but gametes are diploid. T/F
F
Independent assortment occurs in prophase I. T/F
F
Most eukaryotes divide by binary fission T/F
F
The physical location of a gene on the chromosome is called its allele. T/F
F
A ring of the protein FtsZ forms at the future site of the septum T/F
T
After binary fission is completed, two identical cells result T/F
T
Binary fission is a form of asexual division. T/F
T
Haploid organisms can have homologous chromosomes T/F
T
Homologous chromosomes are 99% identical. T/F
T
Homologous chromosomes carry the same types of genes T/F
T
Homologous chromosomes may contain different alleles of a gene. T/F
T
Mitosis and cytoplasmic division result in the formation of two genetically identical cells. T/F
T
The daughter cells are separated by formation of a septum T/F
T
Select each true statement about chromosomes. (Check all that apply.)
The term chromosome means colored body. Each chromosome contains a very long segment of DNA
Males are haploid, females are diploid
bees
The female is the heterogametic sex.
birds
The division of the cytoplasm is called _____
cytokinesis.
Cytokinesis __________. (Check all that apply.)
is a division of the cytoplasm and organelles involves a cleavage furrow in animals yields two cells with nuclei
Centromeres divide in ________
mitosis and meiosis II
What is the correct order of the phases of mitosis?
prophase → metaphase → anaphase → telophase
During __________, two __________ fuse with each other in the process of fertilization to begin the life of a new organism.
sexual reproduction; gametes
What is the correct order of the phases of the cell cycle?
G1 → S → G2 → M
The X to autosome ratio determines sex; females are XX, males are X0
Grasshopper
The male is the heterogametic sex and Y determines maleness
Human
Environmental conditions determine sex.
alligators
Prokaryotic chromosomes __________. (Check all that apply.)
are usually circular pieces of DNA contain many genes contain structural proteins that bind to and organize the DNA
Arrange the following events in the proper order in which they occur during meiosis I. a = Separation of homologous chromosomes b = Synapsis c = Crossing-over d = Independent assortment
b, c, d, a
