MEIOSIS Homework

Discipline: Biology (and other Life Sciences)

Type of Paper: Question-Answer

Academic Level: Undergrad. (yrs 3-4)

Paper Format: APA

Pages: 1 Words: 275


This diagram shows a diploid nucleus (2 n=8) in which chromosome replication has occurred in preparation for mitosis (top) and meiosis (bottom). The nucleus at top right is now in prophase of mitosis; the nucleus at bottom right is now in prophase I of meiosis. Drag the labels to their appropriate targets to correctly identify the various chromosome structures. Labels can be used more than once.

a) non-homologous chromosomes. b) sister chromatids. c) homologous chromosomes. d) centromere. e) nonsister chromatids. f) homologous chromosomes. g) sister chromatids

Which of the following correctly defines a genome
the complete set of an organism's genes

How are sister chromatids and homologous chromosomes different from each other?
Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.
One homologous chromosome comes from the father, and the other comes from the mother. Sister chromatids are identical copies of each other.

Which of the following is true of a species that has a chromosome number of 2n = 16?

Each cell has 8 homologous pairs.

What is "crossing over?"
an exchange of corresponding segments between nonsister chromatids of homologous chromosomes; The result of the exchange of homologous portions of nonsister chromatids is new combinations of genetic material (genetic recombination).

What is the best evidence telling you whether this cell is diploid or haploid?
The cell is diploid because it contains two sets of chromosomes. Only diploid cells contain two sets of chromosomes, one maternal and one paternal. Read about diploid cells.

This chromosome has two chromatids, joined at the centromere. What process led to the formation of the two chromatids?
The two chromatids were formed by duplication of a chromosome.

Human gametes are produced by _____.
Meiosis; Meiosis produces haploid gametes from a diploid parental cell.

Normal human gametes carry ____ chromosomes
23. This is the number of chromosomes in a single set of human chromosomes.

Which of these cells is (are) haploid?
C & D. Once meiosis I is completed, cells are haploid.

A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes
16;  because it is half of 32.

How is meiosis different from mitosis?
Meiosis has two divisions resulting in 4 haploid cells, whereas mitosis has one division resulting in 2 diploid cells identical to the parent cell.
The number of cells produced is different.

Which of the following is true for both mitosis and meiosis?

Sister chromatids are eventually separated.

Your dog has puppies. A pair of homologous chromosomes inside a puppy’s cell 

will have the same genes at the same locations

When, precisely, in the life cycle of a sexually reproducing organism does the transition from diploid to haploid occur? 
Meiosis I

When in the life cycle of a sexually reproducing organism does the transition from haploid to diploid most precisely occur?

The original source of all genetic variation is

Which of the following contribute(s) to the variation in offspring produced by sexual reproduction? 
Crossing over
Mutation Independent assortment Random fertilization

If an organism has a diploid number of 6 chromosomes, how many different combinations of maternal and paternal chromosomes are possible in its gametes?
8 because there are 3 haploid, 2^3 = 8

Which of the following lists the processes involved in Meiosis in the correct order?  
DNA replication → Separation of homologous chromosomes → Cell division → Separation of sister chromatids → Cell division

Human skin cells typically have 46 chromosomes. A human skin cell in G2 phase has ___________ chromosomes, ____________ chromatids, and ______________ DNA molecules.  
46, 92, 92