1.
____ produces haploid gamets, which keeps the chromosomes number from doubling every generations: Meiosis
2.
_____ are proteins used to package DNA in eukaryotes.: Histones
3.
______ are matching pairs of chromosomes that can possess different versions of the same genes.: Homologous Chromosomes
4.
______ consist of DNA wound around histone molecules: Nucleosomes
5.
_______ is at the heart of organismal reproduction, whether by sexual or asexual means: Cell division
6.
________ can spread to other parts of the body and interrupt normal body functions.: Malignant tumors
7.
A _____ is an image that reveals an orderly arrangement of chromosomes.: Karyotype
8.
A human egg cell is fertilized randomly by one sperm, leading to what?: A genetic variety in the zygote.
9.
A human somatic cell______: Is a typical body cell and has 46 chromosomes.
10.
Asexual reproduction conveys an evolutionary advantage when plants are.....: Sparsely distributed and superbly suited to a stable environment
11.
Before a cell divides, it duplicates all of its chromosomes, resulting in two copies called ______.: Sister chromatids
12.
Before a parent cell splits into two, it duplicates its ______, the structures that contain most of the organisms DNA.: Chromosomes
13.
Cancer cells can form ____, abnormally growing masses of body cells.: Tumors
14.
Chromosomes ........: Are made of chromatin, a combination of DNA and protein molecules. Are not visable in a cell until cell division occurs
15.
Cytokinesis typically......: Occurs during telophase, divides the cytoplasm, and is different in plant and animal cells.
16.
Different individuals of a single species have the same number and types of what?: Chromosomes
17.
During cell division, each daughter cell receives what?: One set of chromosomes
18.
During mitosis the _____ a football shaped structure of microtubules guides the seperation of the two sets of daughter chromosomes.: Mitotic spindle
19.
Each eukaryotic chronosome contains one what?: Very long DNA molecule, typically bearing thousands of genes
20.
Endangered species of plants that normally reproduce sexually can by propgated by what?: Asexual reproduction
21.
Every chromosome pair orients ______ of the others during meiosis.: Independently
22.
For any species the total number of chromosome combination that can appear in the gamets is due to what?: Independent assortment
-2n where n is the haploid number
For human:
n=23
2^23= 8,388,608 different chromsome combination possible in a gamete.
23.
Humans are diploid organisms in which ......: Their somatic cells contains two sets of chromosomes and their gamets are haploid having only one set of chromosomes
24.
Humans have ......: Two different sex chromosomes X and Y, twenty-two pairs of matching chromosomes called autosomes.
25.
In ______, the members of a chromosome pair fail to separate during anaphase, producing gamets with an incorrect number of chromosomes. Also occurs during meiosis I or II. If this occurs and a normal sperm cell fertilizes and egg with an extra chromosome, the result is a zygote with a total of 2n+1 chromosome. If the organism survives it will have an abnormal number of genes. Also affects the sex chromosomes.: Nondisjunction
26.
In a eukaryotic cell ......: Most genes are located on chromosomes in the cell nucleus and a few genes are found in DNA in mitochrondia and chloroplasts
27.
In humans, a haploid sperm fuses with a haploid egg during fertilization to form a diploid _____.: Zygote
28.
In meiosis .......: Haploid daughter cells are produced in diploid organisms, interphase is followed by two consecutive divisions, meiosis I and meiosis II. Crossing never occurs. All events unique to meiosis occur during meiosis I.
29.
In mitosis and meiosis, the chromosome duplicate only ___ during the preceding interphase.: Once
30.
Most of the cell cycle is spent in ______: Interphase
31.
Normal plant and animal cells have a _______ that consists of specialized proteins, which send "stop" and "go ahead" signals and certain key points during the cell cycle.: Cell cycle control system
32.
Offspring of _______ are genetically different from their parents and one another.: Sexual reproduction
33.
Reproduction.......: May result in the birth of a new organism but is more commonly involves the production of new cells.
34.
Sexual life cycles involve an alternation of what stages.: Diploid and haploid
35.
Sexual reproduction may convey an evolutionary advantage by......: Speeding adaptations to a changing environment and allowing a population to more easily rid itself of harmful genes.
36.
Sexually Reproducing organisms use meiosis for what?: Reproduction and growth and maintenance
37.
Sister chromatids are joined together at a narrow "waist" called the ______.: Centromere
38.
Spindle microtubules grow from two _____, clouds of cytoplasmic material that in animal cells contain centrioles.: Centrosomes
39.
The ____ is the orderly sequence of events that extend from the time a cell is first formed from dividing parent cell to its own division into two cells.: Cell Cycle
40.
The _____ of multicellular organisms is the sequence of stages leading from the adults of one generation to the adults to the next.: Life cycle
41.
The DNA in a cell is packed into what?: An elaborate, multilevel system of coiling and folding
42.
The mitotic (M) phase includes what two overlapping processes?: Mitosis, in which the nucleus and its contents divide into two daughter nuclei and Cytokinesis, when the cytoplasm is divided into two
43.
The number of cell divisions varies between mitosis and meiosis. Explain.: Mitosis uses one division and produces two diploid cells and meiosis uses two divisions and produces four haploid cells.
44.
The number of chromosomes in a eukaryotic cell depends on what?: The species
45.
The sex chromosome XO means what?: Turner syndrome (female)
46.
The sex chromosome XXY means what?: Klinefelter syndrome (male)
47.
The spread of cancer cells beyond their original site of orgin is ______.: Metastasis
48.
What are the treatments for cancer?: Radiation therapy which damages DNA and disrupts cell division and Chemotherapy which uses drugs that disrupt cell division
49.
What are the two distinct phases in the cell cycle?: Interphase and mitotic phase.
50.
What certain behaviors can decrease the risk of cancer?: Not smoking, exercising adequately, avoiding exposure to the sun, eating a high-fiber low fat diet, performing self-exams, regularly visiting a doctor to identify tumors easily
51.
What does cell division do?: Replaces damaged or lost cells, permits growth, and allows for reproduction.
52.
What happens in asexual reproduction?: Single celled organisms reproduce by simple cell division and there is no fertilization of an egg by a sperm.The lone parent and offspring have identical genes. Examples include some mullticelluar organisms such as sea stars can grow new indiviuals from fragmented pieces and growing a new plant from a clipping is another example of asexual reproduction .
53.
What happens in Sexual Reproduction?: Requires fertilization of an egg and sperm using a special type of cell division called meiosis. Produces offspring that contain a unique combination of genes from the parents.
54.
What happens to a cell during interphase?: Performs its normal functions, doubles everything in its cytoplasm, and grows in size.
55.
What happens when erros occur in meiosis?: Such in mistakes can result in genetic abnormalities that range from mild to fatal.
56.
What is cancer?: A disease of the cell cycle. Cells infected do not respond normally to the cell cycle control system.
57.
What is Down Syndrome?: Is also called trisomy 21, is a condition in which an individual has an extra chromosome 21, and affects one out of every 700 children. The incidence increases with the age of the mother.
58.
What is the four types of mitosis phases: Prophase, Metaphase, Anaphase, and Telophase
59.
What type of cell division is responsible for asexual reproduction and growth and maintenance of multicelluar organisms?: Mitosis
60.
When a cell undergoes reand production, or ______ cells are produced that are genetically identical to each other and to the "parent cell. ": Cell division
61.
When aligned during metaphase I of meiosis, the side-by-side orientation of each homologous pair of chromosomes is a matter of ____.: Chance
62.
When the cell divides, the sister chromatids seperate from each other. Once seperated each chromatid is what?: Considered a full-fledged chromosomes and identical to the orginal chromosome.
