BIOL 3600 - CH.2 HW
Identify the stages of meiosis on the diagram.
1. Chromosomes replicate in interphase 2.crossing over happens between homologous pairs in prophase 1 3.homologous pairs of chromosomes line up in metaphase 1 4.homologous pairs split up in anaphase 1 5.telophase 1 and cytokinesis forms 2 cells 6. spindle fiber reform in prophase 2 7. in metaphase 2 sister chromatids line up in the center of the cell 8.sister chromatids separate in anaphase 2 9.telophase 2 and cytokinesis makes 4 cells.
Place the steps of the prokaryotic cell cycle in order.
1. prokaryotic chromosome attaches to the plasma membrane 2. prokaryotic chromosome replicates 3. cell elongates, pulling each chromosome to an opposite end of the cell 4. plasma membrane and cell wall grow inward and divide the cell 5. 2 genetically identical daughter cells are made
A biologist examines a series of cells and counts 160 cells in interphase, 20 cells in prophase, 6 cells in prometaphase, 2 cells in metaphase, 7 cells in anaphase, and 5 cells in telophase. The complete cell cycle requires 24 hours. Match the average duration to the appropriate cell cycle stage in these cells.
M phase: 4.8 hours Prophase: 2.4 hours Metaphase: 14.4 minutes Telophase: 36 minutes
A cell has a circular chromosome and histone proteins associated with its DNA, but lacks a nuclear membrane. Choose the domain of the cell with the best justification.
the cell belongs to Archaea because it has histone proteins that're present in Archaea/Eukaryota but not in Eubacteria.
What happens during telophase 2 of meiosis?
the nuclear membrane begins to form around haploid sets of chromosomes
Use the word bank to complete the passage describing mitosis and meiosis. All words will be used at least once and most words will be used more than once. A male giant panda has 42 chromosomes in its skin cells. This represents the (1) chromosome number. As the animal's old skin cells die and slough off, cells nearby divide through (2) to produce more skin cells. Germ cells in the animal's testicles undergo (3) to replicate themselves and (4) to produce sperm. The cells produced by mitosis in this panda have a (5) chromosome number and are produced after (6) are pulled apart into separate daughter cells. The cells produced by meiosis 1 in this panda have a (7) chromosome number and are produced after (8) have been pulled apart into separate daughter cells. The cells produced by meiosis 2 in this panda have a (9) chromosome number and are produced after (10) have been pulled apart into separate daughter cells.
1. diploid 2. mitosis 3. mitosis 4. meiosis 5. diploid 6. sister chromatids 7. haploid 8. homologous chromosomes 9.haploid 10.sister chromatids
The fruit fly Drosophila melanogaster has four pairs of chromosomes, whereas the housefly Musca domestica has six pairs of chromosomes. How many different combinations of chromosomes are possible in the gametes of the fruit fly? How many different combinations of chromosomes are possible in the gametes of the house fly? Based on chromosome number, in which species would you expect to see more genetic variation among the progeny?
16 fruit fly chromosome combinations 64 house fly chromosome combinations the house fly
The somatic cell of a cat contains 38 chromosomes38 chromosomes (2𝑛=38).(2n=38). How many chromosomes and how many DNA molecules would the first polar body of this cat have?
19 chromosomes, 38 DNA molecules
Cell division by mitosis is a mechanism of asexual cell replication. Some single celled organisms reproduce by cell division and cell division allows multicellular organisms to grow and repair damaged cells. What's a product of cell division by mitosis?
2 cells genetically identical to the original cell
Humans autosomal cells have two copies each of 23 unique chromosomes. Match each cell division event and cell type according to the number of chromatids present.
23 chromatids: spermatozoa and ootid 46 chromatids: G1 prior to mitosis 92 chromatids: G2 prior to mitosis
Suppose a scientist measures the amount of DNA per cell of a particular diploid species at various stages of meiosis. She finds that the meiotic cells contain 3.7 pg,3.7 pg, 7.3 pg pg,7.3 pg pg, or 14.6 pg14.6 pg of DNA. Match wach stage of the cell cycle to the amount of DNA in a cell at that stage.
3.7pg: after cytokinesis of meiosis 2 7.3pg: metaphase 2, G1 14.6pg: prophase 1, G2, telophase 1 before cytokinesis
Suppose a diploid slime mold is completely heterozygous at all 12 of its chromosomes (2𝑛=12).(2n=12). How many different combinations of gametes can be produced by this slime mold, assuming no homologous recombination between chromosomes?
64 different combinations
Intracellular components can be labeled with a fluorophore, and the dynamic movements in the cell can be seen. Arrange the images of cell division stages in order from interphase to cytokinesis.
D, C, B, A, E
The role of cell division in eukaryotic life cycles varies among types of organisms. Match the type of organism to the appropriate life cycle based on the cell‑division processes. Not all organisms will be placed.
Dog, tree, mushroom
On average, what fraction of the genome in the pairs of humans would be exactly the same if no crossing over took place? For the purposes of this question only, ignore the special case of the X and Y sex chromosomes and assume that all genes are located on nonsex chromosomes. Also, assume that the uncle and niece are related by a sibling and not by marriage alone.
Father+Child: 1/2 Mother+Child: 1/2 Full siblings: 1/2 Half siblings: 1/4 Uncle+Niece: 1/4 Grandparent+Grandchild: 1/4
Label each phase of the cell cycle with the appropriate name/description.
G0 phase, protein synthesis and preparation for DNA replication, DNA replication, last stage of interphase, and cell division
Match the checkpoint to its function. What are checkpoints?
G1/S: maintains the cell until necessary enzymes for replication are synthesized. G2/M: detection of DNA damage after replication. Spindle-Assembly: ensures that each chromosome is attached to spindle fibers from opposite poles. transition points during the cell cycle that ensure all cellular components are functioning properly.
Classify each cell as diploid or haploid.
Haploid: microspore, 1st polar body, spermatid, megaspore, ovum, and 2ndary oocyte Diploid: primary spermatocyte, microsporocyte, oogonium, and spermatogonium
Consider 2 cells where 1 cell is haploid and the other diploid. What differences between the 2 cells is seen during prophase of mitosis?
In the haploid cell, only 1 pair of DNA molecules are present while in the diploid cell 2 pairs of DNA molecules are present.
Cells are categorized as either prokaryotic or eukaryotic. Classify the characteristics as being prokaryotic, eukaryotic, or both. Move each description into the correct category.
Prokaryotic: relatively small/typically less than 10 um in size and lacks membrane-bound organelles. Eukaryotic: complete copy of DNA stored in multiple chromosomes. Both: has DNA and uses ribosomes to synthesize proteins.
Identify each stage of M phase.
Prophase, metaphase, anaphase, telophase, and cytokinesis
Normal somatic cells of horses have 64 chromosomes (2𝑛=64).(2n=64). Match the number of chromosomes and the number of DNA molecules that will be present in the types of horse cells listed in the table. Horse Cell Type-Chromosomes-DNA Molecules
Spermatogonia-64-64 1st Polar Body-32-64 Primary Oocyte-64-128 2ndary Spermatocyte-32-64
What're the functions of the mitotic cell division?
asexual reproduction, growth of multicellular organisms, and replacement of cells
The cells shown in the image are from a rare species of plant and show different stages of mitosis/meiosis. Determine the diploid number of chromosomes/2n in this species of plant. Match each cell to the specific stage of meiosis/mitosis, chromosome number, and DNA molecules per cell.
diploid: 6 chromosomes Anaphase 1 of meiosis-6 chromosomes-12 DNA molecules Anaphase of mitosis-12-12 Anaphase 2 of meiosis-6-6
What happens during prophase 1 of meiosis?
homologous chromosomes form and crossing over occurs between them.
Female honey bees are diploid and male honey bees are haploid. The haploid males produce sperm and can successfully mate with diploid females. Fertilized eggs develop into females and unfertilized eggs develop into males. How does the process of sperm production in male honey bees differ from sperm production in other animals?
male honey bees use mitosis while other animals use meiosis
A section of Elodea leaf is stained and examined under a microscope. The total number of cells in each stage of the cell cycle is recorded and presented in the table. If the compete cell cycle in an Elodea leaf needs 24 hours, what's the average duration of metaphase in the cycle? Assume no cells are in G0. M Phase-Number of Cells Interphase-150 Prophase-20 Prometaphase-11 Metaphase-9 Anaphase-5 Telophase-1 Total-196.000
metaphase: 1.102 hours
Label eight structures on generalized eukaryotic cell
plasma membrane, mitochondrion, cytoskeleton, endoplasmic reticulum, lysosomes, nucleus, ribosomes, and Golgi apparatus
Meiosis and mitosis are both forms of cell division. However, the outcomes of these processes differ. Consider a diploid organism with two sexes. Why does meiosis usually make genetic variation while mitosis doesn't?
sister chromatids aren't genetically identical due to crossing over during meiosis, meiosis makes 4 genetically different haploid cells, and independent assortment results in alleles for a gene being passed separately to gametes during meiosis.
