Biology chapter 13
telophase I
"two" - ending with two nearly formed nuclei *ending meiosis with two new cells*
prophase II
- chromosomes and the spindles starting to form NO homologous pairs or cross over
homologous chromosomes
Chromosomes that have the same sequence of genes and the same structure
During _____ a spindle forms in a haploid cell. telophase I and cytokinesis prophase I metaphase II anaphase II prophase II
Prophase II is essentially the same as mitotic prophase except that the cells are haploid.
We can see that the chromosomes are duplicated and lined up by a homologous pair, this happens in meiosis I or meiosis II?
This only happens at the start of meiosis I
metaphase II
in the middle but not as pairs like metaphase I
life cycle
is the generation to generation sequence of stages
Genetics
is the scientific study of heredity
telophase II
nuclei reform and the 2 cells are each going to divide which then 4 cells are going to be formed
alternation of generations
plants and some species of algae exhibit a second type of life cycle
Which processes lead to most genetic variation in sexually reproducing organisms? Select all that apply. random fertilization cytokinesis independent assortment of chromosomes in meiosis crossing over
random fertilization, independent assortment of chromosomes in meiosis, crossing over
metaphase I
"middle" - chromosomes are in the middle of the cell as pairs
anaphase I
"away" - the chromosomes are going to be pulled away by the spindle fibers
prophase I
"before" - chromosomes are going to condense or thicken - line up with homologous pair
If a cell has 24 chromosomes, how many chromosomes would each of its four daughter cells have after meiosis? 1.24 2.36 3.12 4.6
12 because Meiosis is a reduction division that reduces the number of chromosomes passed on to daughter cell
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes. 1. 64 2. 30 3. 8 4. 32 5. 16
16 : because it is half of 32.
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)? 8 16 32 4 2
16 because , 2x8=16
Normal human gametes carry _____ chromosomes. 1. 23 pairs of 2. 46 pairs of 3. 5 4. 23 5. 46
23: This is the number of chromosomes in a single set of human chromosomes.
What is the ploidy of organisms that have two sets of chromosomes? 3n n 2n 4n
2n: An organism that has two sets of chromosomes has a ploidy of 2n.
haploid cell
A cell containing only one set of chromosomes (n).
diploid cell
A cell containing two sets of chromosomes (2n), one set inherited from each parent.
karyotype
A display of the chromosome pairs of a cell arranged by size and shape.
During _____ sister chromatids separate. anaphase II interphase prophase II prophase I metaphase I
Anaphase II is essentially the same as mitotic anaphase except that the cell is haploid.
Autosomes
Any chromosome that is not a sex chromosome
Asexual reproduction and sexual reproduction differ in all but which of the following ways? 1.Asexual reproduction requires only mitosis, whereas sexual reproduction always involves meiosis. 2.Asexual reproduction is utilized only by fungi and protists, whereas sexual reproduction is utilized only by plants and animals. 3.Asexual reproduction involves a single parent, whereas sexual reproduction involves two. 4.Individuals reproducing asexually transmit 100% of their genes to their progeny, whereas individuals reproducing sexually transmit only 50%. 5.Asexual reproduction produces offspring that are genetically identical to the parents, whereas sexual reproduction gives rise to genetically distinct offspring.
Asexual reproduction is utilized only by fungi and protists, whereas sexual reproduction is utilized only by plants and animals
Which of these statements is false? 1.At sexual maturity, ovaries and testes produce diploid gametes by meiosis. 2.In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. 3.In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY). 4.Sexual life cycles differ with respect to the relative timing of meiosis and fertilization. 5.Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote.
At sexual maturity, ovaries and testes produce diploid gametes by meiosis, because the total amount of ovaries are already there except testes need to be made
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids. telophase II metaphase II telophase I telophase interphase
At the end of telophase I and cytokinesis, there are two haploid cells with chromosomes that consist of two sister chromatids each.
At the end of _____ and cytokinesis there are four haploid cells. prophase II prophase I interphase anaphase I telophase II
At the end of telophase II and cytokinesis there are four haploid cells.
When does crossing over occur?
Crossing over occurs during prophase I when homologous chromosomes loosely pair up along their lengths. Crossing over occurs only between nonsister chromatids within a homologous pair of chromosomes, not between the sister chromatids of a replicated chromosome. Only segments near the ends of the chromatids, not segments nearest the centromeres, can exchange DNA.
Homologous chromosomes migrate to opposite poles during _____. prophase II anaphase I telophase II and cytokinesis metaphase II metaphase I
During anaphase I sister chromatids remain attached at their centromeres, and homologous chromosomes move to opposite pole
Which of the following is true of a species that has a chromosome number of 2n = 16? 1.A gamete from this species has 4 chromosomes. 2.The species has 16 sets of chromosomes per cell. 3.The species is diploid with 32 chromosomes per cell. 4.Each cell has 8 homologous pairs. 5.During the S phase of the cell cycle there will be 32 separate chromosomes.
Each cell has 8 homologous pairs
Which of the following is true of a species that has a chromosome number of 2n = 16? 1.A gamete from this species has four chromosomes. 2.The species is diploid with 32 chromosomes per cell. 3.The species has 16 sets of chromosomes per cell. 4.Each cell has eight homologous pairs. 5.During the S phase of the cell cycle there will be 32 separate chromosomes.
Each cell has eight homologous pairs
The human genome is minimally contained in which of the following? 1.Every human cell 2.The entire human population 3.Each human chromosome 4.Each human gene 5.The entire DNA of a single human
Every human cell
True or false? A haploid organism has one pair of homologous chromosomes.
False : A haploid organism only has one set of chromosomes, so it has no homologous chromosomes.
Which of the following is a true statement about sexual vs. asexual reproduction? 1.In asexual reproduction, offspring are produced by fertilization without meiosis. 2.Sexual reproduction requires that parents be diploid. 3.Asexual reproduction produces only haploid offspring. 4.In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. 5.Asexual reproduction, but not sexual reproduction, is characteristic of plants and fun
In sexual reproduction, individuals transmit 50% of their genes to each of their offspring
A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? 1.It must be sexually reproducing. 2.Its gametes must have 23 chromosomes. 3.It must be human. 4.It must be an animal. 5.It must be a primate.
Its gametes must have 23 chromosomes
Human gametes are produced by _____. 1. meiosis 2. fertilization 3. mitosis 4. the cell cycle 5. asexual reproduction
Meiosis : produces haploid gametes from a diploid parental cell
If you look through a mircoscope and see a cell with chromosomes lined up two by two what stage of cellular reproduction are you looking at?
Meiosis I : is the only time that chromosomes line up by homologous pairs because after crossing over in Meiosis I, the two sister chromatids of each chromosomes are NOT genetically identical
Homologous chromosomes move toward opposite poles of a dividing cell during 1.meiosis II. 2.mitosis. 3.fertilization. 4.meiosis I. 5.binary fission.
Meiosis I, because within Meiosis II the homologous chromosomes are not together or identical
Which of the following statements about meiosis and mitosis is true? 1.Each daughter cell produced during meiosis and mitosis is genetically identical to the parent cell. 2.Meiosis II is similar to mitosis in that sister chromatids of each chromosome separate. 3.In mitosis and meiosis I, homologous chromosomes move independently of each other. 4.In meiosis II and mitosis, a diploid cell divides.
Meiosis II is similar to mitosis in that sister chromatids of each chromosome separate, Both meiosis II and mitosis are cell divisions involving the separation of sister chromatids.
During _____ chromosomes align single file along the equator of a haploid cell. prophase I metaphase I telophase I and cytokinesis anaphase I metaphase II
Metaphase II is essentially the same as mitotic metaphase except that the cell is haploid.
At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? 1.Metaphase 2.Telophase 3.Prophase 4.Anaphase 5.Interphase
Metaphase, because they are lined up within the middle making it easier to see
Out of mitosis and meiosis which process occurs in the hand ?
Mitosis: Mitosis goes on continuously in most parts of the body, whereas meiosis takes place only in the gonads.
Which life cycle stage is found in plants but not animals? 1.Unicellular diploid 2.Multicellular haploid 3.Multicellular diploid 4.Gamete 5.Zygote
Multicellular Hapliod, because plants go through mitosis
Once meiosis I is completed cells are, haploid or diploid?
Once meiosis I is completed cells are haploid
What is the composition of a tetrad at the beginning of prophase I? Two sister chromatids Four different chromosomes Two pairs of homologous chromosomes One pair of homologous chromosomes
One pair of homologous chromosomes, One pair of homologous chromosomes
Genes
Parents endow their offspring with coded information in the form of heredity
meiosis
cell division reduces the number of sets of chromosomes from two to one in the gametes
Synapsis occurs during _____. prophase I anaphase II metaphase II telophase I and cytogenesis prophase II
Synapsis, the pairing of homologous chromosomes, occurs during prophase I.
What is the point of attachment between two sister chromatids of a duplicated chromosome
The centromere is the point of attachment between two sister chromatids of a duplicated chromosome.
Which structure is directly correlated with the production of genetic variability in the daughter cells produced during meiosis? Chiasma Tetrad Synapsis Centromere
The chiasma is an X-shaped structure formed from the crossing over of homologous chromosomes, which can then exchange segments at the crossover sites.
What information can not be obtained from an individual's karyotype? 1.The ploidy of the individual 2.The sequence of bases of a particular gene 3.The number of autosomes in the individual 4.The types of chromosomes present in the individual
The sequence of bases of a particular gene, Karyotypes only give information about the chromosomes in an individual.
A cell divides to produce two daughter cells that are genetically different. 1.The statement is true for meiosis II only. 2.The statement is true for mitosis and meiosis I. 3.The statement is true for meiosis I only. 4.The statement is true for mitosis and meiosis II. 5.The statement is true for mitosis only.
The statement is true for meiosis I only
Independent assortment of chromosomes occurs. 1.The statement is true for meiosis I only. 2.The statement is true for mitosis and meiosis I. 3.The statement is true for mitosis only. 4.The statement is true for meiosis II only. 5.The statement is true for mitosis and meiosis II.
The statement is true for meiosis I only
Heredity
The transmission of traits from one generation to the next
A chromosome that 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.
How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis? 1.They have the same number of chromosomes and half the amount of DNA. 2.They have half the amount of cytoplasm and twice the amount of DNA. 3.They have half the number of chromosomes and one-fourth the amount of DNA. 4.They have half the number of chromosomes and half the amount of DNA. 5.They have twice the amount of cytoplasm and half the amount of DNA.
They have half the number of chromosomes and one-fourth the amount of DNA.
sex chromosomes
X and Y chromosomes.
Locus
a gene's specific location along the length of a chromosome
asexual reproduction
a single individual ( like a yeast cell or an amoeba) is the sole parent and passes copies of all its offspring without the fusion of gametes ( plants )
A human cell containing 22 autosomes and a Y chromosome is 1.a zygote. 2.a sperm. 3.a somatic cell of a male. 4.an egg. 5.a somatic cell of a female.
a sperm
Somatic Cells
all cells of the body except the gametes
Which of the following might result in a human zygote with 45 chromosomes? 1.an error in the alignment of chromosomes on the metaphase plate 2.an error in either egg or sperm meiotic anaphase 3.failure of the egg nucleus to be fertilized by the sperm 4.lack of chiasmata in prophase I 5.fertilization of a 23 chromosome human egg by a 22 chromosome sperm of a closely related species
an error in either egg or sperm meiotic anaphase
Clone
an individual that reproduces asexually
Gametes
are the vehicles that transmit genes from one generation to the next ( sperm and egg )
anaphase II
chromatids are getting pulled away by spindle fibers UNLIKE anaphase I is the pulling away of chromosomes
zygote
fertilized egg
Cytokinesis
follows splitting the cytoplasm
Meiosis II typically produces _____ cells, each of which is _____ four ... haploid four ... identical to the other four ... diploid two ... haploid two... diploid
four..haploid, At the end of meiosis II there are typically 4 haploid cells.
Meiosis II is similar to mitosis in that 1.the daughter cells are diploid. 2.the chromosome number is reduced. 3.sister chromatids separate during anaphase. 4.homologous chromosomes synapse. 5.DNA replicates before the division.
sister chromatids separate during anaphase
Independent assortment of chromosomes is a result of 1.the relatively small degree of homology shared by the X and Y chromosomes. 2.the random distribution of the sister chromatids to the two daughter cells during anaphase II. 3.the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. 4.the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I, the random nature of the fertilization of ova by sperm, the random distribution of the sister chromatids to the two daughter cells during anaphase II, and the relatively small degree of homology shared by the X and Y chromosomes. 5.the random nature of the fertilization of ova by sperm.
the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I
fertilization
this union of gametes, culminating in the fusion of their nuclei
sexual reproduction
two parents give rise to offspring that have unique combinations of genes inherited from the two parents
Meiosis I produces _____ cells, each of which is _____. four ... haploid two... diploid two... identical to the other two ... haploid four ... diploid
two.. haploid, At the end of meiosis I there are two haploid cells.
