Chapter 13: Meiosis Flashcards
What is heredity?
The transmission of traits from one generation to the next
What is variation?
Differences in appearance in an offspring from parents to siblings
What is genetics?
The scientific study of heredity and variation
What are genes
The units of heredity and are made up of DNA
What are gametes
Sperm and egg
What is the locus?
The specific position of a gene along a chromosome
What is asexual reproduction?
The passing of genes to offspring without the fusion of gametes
What is sexual reproduction?
The passing of genes from two parents
What is the karyotype?
The ordered display of pairs of chromosomes
What are homologous chromosomes?
The two chromosomes in each pair
What are sex chromosomes?
The X and Y chromosomes
What are autosomes?
The remaining 22 pairs of chromosomes
What is a diploid cell?
2n or two sets of chromosomes
What is the diploid cell for humans?
2n=46
What is a haploid?
A single set of chromosomes such as a gamete
What is the haploid in humans?
N=23
What is fertilization?
The union of gametes (sperm and egg)
What is a zygote?
A fertilized egg and has one set of chromosomes from each paper
What is meiosis?
Gametes being reproduced and excludes replication of body cells
What is meiosis I?
The separating of homologous chromosomes
What is meiosis II?
The separating of sister chromatids
What is prophase I?
Where each chromosome pairs with its homologous and crossing over occurs
What are chiasmata?
In prophase I and is the X shaped regions where sites are
What is metaphase I?
Where homologous line up at the metaphase plate
What is anaphase I?
Where homologous chromosomes separate and move toward the opposite poles
What is telophase I and cytokinesis?
Where each half of a cell has haploid set of chromosomes. Also, cytokinesis occurs simultaneously and forms haploid daughter cells
What is prophase II?
Where spindle apparatus forms and where chromosomes move toward the metaphase
What is metaphase II?
Where sister chromatids are no longer identical and attach to microtubules and arrange at the metaphase plate
What is anaphase II?
Where sister chromatids separate and sister chromatids move into two new individual chromosomes toward opposite poles
What is telophase II and cytokinesis?
Where chromosomes are at opposite poles and nuclei forms while chromosomes condense
What is the difference between mitosis and meiosis?
Mitosis produces diploid that identical while meiosis produces haploids that are unique
What is unique to meiosis I?
Synapsids/crossing over, homologous pairs at metaphase plate, and separation of homologous
What is the original source of genetic diversity?
Mutations or change in an organism DNA
What do mutations do?
Create different versions of genes called alleles
Which of the following phrases defines the term genome?
the complete set of an organism’s genes and other DNA sequences
Asexual reproduction occurs during which of the following processes?
Mitosis
Which of the following statements about reproduction is correct?
In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.
The figure represents the nucleus of an animal cell about to enter mitosis. How many different chromosomes are present in the diagram?
4
Which of the following statements is true of a species that has a chromosome number of 2n = 16?
Each diploid cell has eight homologous pairs of chromosomes.
Which of the following processes best describes the mechanism of gamete production in plants?
gametophytes produce gametes by mitosis
A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?
It produces gametes with 23 chromosomes.
Which of the following statements best describes homologous chromosomes?
They carry information for the same traits.
Many diploid organisms produce haploid gametes for reproduction. Which of the following best describes how the diploid number of chromosomes is restored in the offspring of these organisms?
fertilization combines chromosomes from each parent into resulting zygote
Which of the following statements about the human X chromosomes is correct?
It carries genes that influence an individual’s biological sex.
Which of the following statements correctly describes a karyotype?
It is an organized image of a cell’s chromosomes.
Which of the following processes will most likely produce a human zygote with 45 chromosomes?
an error during anaphase II while the sperm was produced
A cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II. Which of the following statements describes its genetic contents?
It has half the amount of DNA as the cell that began meiosis.
The somatic cells of a particular plant each contain a total of 46 chromosomes. How do the chromosomes of this plant differ from the chromosomes of humans, who also have a total of 46?
The genes on this plant’s largest chromosome are significantly different than those on the largest human chromosome.
Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?
The cells are haploid, and the chromosomes are each composed of two chromatids.
Which of the following events happens at the conclusion of meiosis I?
Homologous chromosomes of a pair are separated from each other.
During which of the following processes do sister chromatids separate from each other?
during both mitosis and meiosis II
Which of the following processes occurs in meiosis but not in mitosis?
synapsis of chromosomes
