Unit 2 Study Guide
List the types of cells that are formed as a result of meiosis
Gamete cells (sex cells) - sperm and eggs
What is this definition of...? are an organism's reproductive cells. They are also referred to as sex cells.
Gametes
What is this definition of...? A segment of DNA that provides the instructions for making a protein.
Gene
Which of the following statements regarding genetic diversity is false? Genetic diversity is enhanced by random fertilization. Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. Genetic diversity is enhanced by mitosis. Genetic diversity is enhanced by crossing over during meiosis
Genetic diversity is enhanced by mitosis.
Describe how meiosis contributes to genetic variation
Genetic variation in gametes results from - Independent assortment - Random fertilization - Crossing over
What is this definition of...? An organism's complete set of DNA
Genome
What is this definition of...? is the quality of a cell or organism having a single set of chromosomes.
Haploid
What is this definition of...? Made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci. One homologous chromosome is inherited from the organism's mother; the other is inherited from the organism's father.
Homologous chromosomes
Describe DNA replication
1. DNA unwinds at the origin of replication 2. New bases are added to the complementary parental strands. One new strand is made continuously, with the other strand is made in pieces. 3. Primers are removed, new DNA nucleotides are put in place of the primers and the backbone is sealed by DNA ligase.
Describe the stages of the cell cycle and the events that take place in each stage
1. Interphase: duplication of cell contents G1—growth, increase in cytoplasm S—duplication of chromosomes G2—growth, preparation for division 2. Mitotic phase: division - Mitosis—the division of the nucleus - Cytokinesis—the division of cytoplasm
What is this defining...? describes how different genes separate from one another when reproductive cells develop
Independent assortment
During which stage of the cell cycle is DNA replicated? Interphase Mitosis Cytokinesis
Interphase
When does the replication of DNA occur?
It occurs during the synthesis phase (S phase) - before the cell enters mitosis or meiosis.
What does the haploid generation of a plant do?
It produces gametes and is called the gametophyte.
Which of the following is not a potential advantage of asexual reproduction? It allows animals that do not move around to produce offspring without finding mates. It allows animals that are genetically well suited to a particular environment to quickly expand their populations. It produces genetically diverse populations.
It produces genetically diverse populations.
What does the diploid generation do?
It produces spores and is called the sporophyte
What is this definition of...? The position of a gene
A locus
What is the complementary sequence to the DNA strand TCGATGG? TCGATGG GGTAGCT AGCTACC
AGCTACC
Seminal vesicles (produce sugar-rich fluid), prostate gland (produces alkaline fluid), bulbourethral gland (produces sticky fluid)
Accessory glands in male reproductive system
List the nucleotides that make up DNA
Adenine Guanine Cytosine Thymine
List the four nucleotides that make up RNA
Adenine Guanine Cytosine Uracil
Which of the following nucleotides are found in DNA? Select ALL that apply. Adenine (A) Uracil (U) Thymine (T) Guanine (G) Cytosine (C)
Adenine (A) Thymine (T) Guanine (G) Cytosine (C)
What is this definition of...? Different versions of the same gene are called
Alleles
Which of the following statements is false? Gametes are haploid cells. Two haploid cells fuse during fertilization. An X chromosome is an autosome. A zygote is a fertilized egg.
An X chromosome is an autosome.
Sister chromatids separate and are pulled towards opposite poles of the cell
Anaphase
Match the stages of mitosis with the correct description.
Anaphase - Sister chromatids separate and move towards opposite poles (sides) of the cell Prophase - Chromosomes are condensed; nuclear envelope breaks up Telophase - Chromosomes start unwinding; nuclear envelope is formed Metaphase - Chromosomes are lined up in the middle of the cell
Chromosomes align on the spindle equator in the middle of the cell
Metaphase
Which of the following statements regarding the function of mitosis is false? Mitosis allows organisms to grow. Mitosis allows organisms to generate genetic diversity. Mitosis allows organisms to reproduce asexually. Mitosis allows organisms to repair tissues.
Mitosis allows organisms to generate genetic diversity.
Describe how bacteria divide by binary fission
Bacteria reproduces by binary fission. It begins when the DNA of the bacterium divides into two. The cell then extends and spits into two daughter cell each with identical DNA to the parent cell.
Site of egg formation in females
Ovaries
Also known as fallopian tubes; tube connecting the ovaries and the uterus; uses cilia to 'sweep' egg towards uterus; site of fertilization
Oviduct
Chromatin condenses and chromosomes become visible; centrioles move to opposite ends of the cell and mitotic spindle forms. Nuclear envelope disintegrates and microtubules attach to chromosomes
Prophase
The genetic material is duplicated during G1. S. G2.
S
Which portions of nucleotides form the 'backbone' of the DNA double helix? Select ALL correct answers. Sugar Phosphate Nitrogenous bases
Sugar Phosphate
Chromosomes begin to uncoil, reforming chromatin; nuclear envelope reforms; final stage of mitosis
Telophase
Site of sperm formation in males
Testes
DNA that is wrapped around proteins and has a 'beads on a string' appearance is called ___________. Chromatin Chromosome Necklace DNA
Chromatin
What is this defining...? is the swapping of genetic material that occurs in the germline. During the formation of egg and sperm cells, also known as meiosis, paired chromosomes from each parent align so that similar DNA sequences from the paired chromosomes _____ one another.
Crossing over
Which of the following statements regarding the differences between mitosis and meiosis is false? In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced. Cells produced by mitosis are diploid, whereas cells produced by meiosis are haploid. Crossing over is a phenomenon that creates genetic diversity during mitosis.
Crossing over is a phenomenon that creates genetic diversity during mitosis.
What is this definition of...? is a cell or organism that has paired chromosomes, one from each parent.
Diploid
Describe the alternation of generations that occur during plants life cycles
During sexual reproduction plants have an alternation of generations in which the haploid and diploid stages are distinct, multicellular bodies.
Contrast mitosis and meiosis
- A difference is mitosis is a single nuclear division that results in two nuclei, while meiosis is two nuclear divisions that result in four nuclei. - Another difference is that cells produced by mitosis will function in different parts of the body, while cells produced by meiosis will only participate in sexual reproduction.
Compare mitosis and meiosis
- A similarity is mitosis and meiosis are both forms of division of the nucleus in eukaryotic cells. - Another similarity is meiosis and mitosis are both preceded by one round of DNA.
Describe meiosis I
- Each pair of homologous chromosome lines up next to each other and then the two homologous chromosomes separate. - Produces daughter cells with half as many chromosomes as the parent cell (homologous chromosome separate)
Give examples of circumstances that require cell division
- Growth - The replacement of damaged cells - Development from an embryo into an adult
Describe sexual reproduction
- It involves the fusion of two haploid sex cells called gametes (sperm and egg) formation of a zygote. - Sexual reproduction increases the genetic variability among offspring and chances that some of the varying offspring will survive and reproduce.
Describe asexual reproduction
- It is reproduction without sex - creates offspring that are genetically identical to the parent. -P ermits organisms to multiply quickly without spending time or energy-producing sperm and eggs. - Asexual reproduction produces genetically identical offspring, which limits a population's chances of surviving periods of environmental change
Contrast the structure of DNA and RNA
- The 5-carbon sugar in DNA is deoxyribose while the 5-carbon sugar in RNA is ribose. - DNA is made up of two strands that are twisted called a double helix, while RNA is just a single-stranded molecule.
Describe meiosis II
- The sister chromatids of each chromosome are separated. As a result, each daughter cell gets one copy of chromosome from the pair of homologous chromosomes that was in the original cell. (Sister chromatids separate)
Compare the structure of DNA and RNA
- They are both a polymer of nucleotides - They are both made up of three parts - They both have four types of nitrogenous bases
Seed dispersal mechanisms include relying on...
- wind - hitching a ride on animals - fleshy, edible fruits that attract animals, which then deposit the seed in a supply of natural fertilizer at some distance from the parent plant
What is the cell cycle?
The cell cycle is an ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division
Define Cell Division
The division of a cell into two daughter cells with the same genetic material
Define cytokinesis
The division of the cytoplasm
Define Mitosis
The division of the nucleus
What are fruits?
They are ripened ovaries of flowers and adaptations that help disperse seeds
Describe the law of complimentary base paring
This is when Adenine pairs with Thymine and Cytosine pairs with Guanine. - This means that the two strands are complementary to each other.
What is this definition of...? is the cell formed when two gametes fuse during fertilization. The DNA material from the two cells is combined in the resulting_____
Zygote
In flowering plants the portion of the flower where pollen is produced is the____________. anther stigma ovary
anther
The female reproductive organ of a flower, consisting of the stigma, style, and ovary.
carpels
DNA differs from RNA because DNA contains thymine in place of uracil. consists of a single rather than a double polynucleotide strand. contains the sugar ribose rather than the sugar deoxyribose.
contains thymine in place of uracil.
The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called mitosis cytokinesis binary fission Telophase
cytokinesis
A mechanism of fertilization in angiosperms, in which two sperm cells unite with two cells in the embryo sac to form the zygote (diploid) and endosperm (triploid)
double fertilization
The embryo implants in the __________. oviduct ovary endometrium of the uterus
endometrium of the uterus
Stores sperm; site of sperm maturation
epididymis
Which of the following is a feature of plant cell division that distinguishes it from animal cell division? formation of a cell plate formation of a cleavage furrow production of four (rather than two) new cells per mitotic division
formation of a cell plate
A mature ovary of a flower that protects dormant seeds and aids in their dispersal.
fruit
Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are... homologous chromosomes. heterologous chromosomes. complementary chromosomes.
homologous chromosomes.
Eukaryotic cells spend most of their cell cycle in which phase? interphase prophase Metaphase
interphase
A(n) ____________ is the physical location of a gene on a chromosome. allele locus address
locus
reductive division that results in production of haploid gametes
meiosis
Nondisjunction occurs when a portion of a chromosome breaks off and is lost. two chromosomes fuse into one. members of a chromosome pair fail to separate.
members of a chromosome pair fail to separate.
Fertilization in the female reproductive tract typically occurs in the ovary oviduct (Fallopian tube) uterus
oviduct (Fallopian tube)
What are flowers the site of?
pollination and fertilization.
The phase of mitosis during which the mitotic spindle begins to form is interphase prophase metaphase Anaphase
prophase
plant embryo and a food supply (endosperm) encased in a protective covering
seed
Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called chromatin. sister chromatids. nucleoli.
sister chromatids.
The pollen-producing male reproductive organ of a flower, consisting of an anther and filament.
stamens
During which phase of mitosis does the nuclear envelope re-form? anaphase metaphase telophase
telophase
The human egg is swept through the oviduct toward the uterus by rhythmic contractions of the oviduct rhythmic contractions of the uterus the beating of cilia in the oviduct
the beating of cilia in the oviduct
Muscular organ in the pelvic cavity of the female, in which the embryo is nourished and develops before birth; lined with endometrium
uterus
Long, narrow tube carrying sperm from epididymis to ejaculatory duct
vas deferens