Bio Exam 2 (Chpt. 6, 7, 8, & 10)

What is the phase order of cellular replication & division under Mitosis?

1. Interphase 2. Prophase 3. Prometaphase 4. Metaphase 5. Anaphase 6. Telophase

What is the phase order of Meiosis I & Meiosis II?

1. Interphase 2. Prophase I 3. Prometaphase I 4. Metaphase I 5. Anaphase I 6. Telophase I 7. Prophase II 8. Prometaphase II 9. Metaphase II 10. Telophase II 11. Gametes

Be able to identify the following from a drawing of a cell or a karyotype: o number of chromosomes o number of sets of chromosomes o number of chromosomes in one set o which chromosomes belong in each set o ploidy level of the cell or the individual o number of pairs of homologous chromosome

1. Number of Chromosomes: 46 chromosomes 2. Number of Sets of Chromosomes: 2 sets; diploid 3. Number of chromosomes in one set: 22 pairs of autosomal chromosomes and one pair of sex chromosomes (23 pairs total) 4. Which chromosomes belong in each set: ? 5. Ploidy level of the cell/individual: diploid has 2 sets 6. Number of pairs: 23 pairs

When crossing two homozygous recessive parents (pp x pp), what percentage of the offspring have have the same genotype (pp)?

100 percent; all offspring will also be true-breeding for white flowers and will only produce recessive (p) alleles.

Chromosomal number for our species (Homo sapiens)

46 chromosomes

A pea plant that is heterozygous for the flower color gene makes gametes. What is the probability that a specific gamete contains the recessive allele for flower color?

50 percent

Consider a gene with two alleles that show complete dominance. When a homozygous recessive individual (qq) is crossed with a heterozygous individual (Qq), they have a 50 percent chance of producing a homozygous recessive offspring. The next time these two individuals breed, what are the chances that they will once again have a homozygous recessive progeny?

50 percent; the probabilities remain the same each time.

What is the phenotype ratio of two heterozygous mate's progeny?

9:3:3:1

Single nucleotide polymorphism (SNP)

A DNA sequence variation that occurs when a single nucleotide (adenine, thymine, cytosine, or guanine) in the genome sequence is altered and the particular alteration is present in at least 1% of the population.

Biomarker

A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease

In the reproductive cloning of an animal the genome of the cloned individual comes from __________.

A body cell

Germ cell

A cell that develops into a reproductive cell, which is an egg in females and a sperm in males

Parent cell

A cell that is the source of other cells, as a cell that divides to produce two or more daughter cells

Sticky ends

A fragment of DNA (often produced by a staggered cut on the DNA using restriction enzymes) in which the terminal portion has a stretch of unpaired nucleotides, and the strands are not of the same length.

Proto-oncogene

A gene involved in normal cell growth; Mutations may cause it to become an oncogene, which can cause the growth of cancer cells.

Whole Genome Sequencing (WGS)

A laboratory process that is used to determine nearly all of the approximately 3 billion nucleotides of an individual's complete DNA sequence, including non-coding sequence.

Nucleotide

A molecule consisting of a nitrogen-containing base (adenine, guanine, thymine, or cytosine in DNA; adenine, guanine, uracil, or cytosine in RNA), a phosphate group, and a sugar (deoxyribose in DNA; ribose in RNA).

What carries a gene from one organism into a bacteria cell?

A plasmid

Punnett square

A tool for showing possible alleles of offspring in a test cross.

Tumor suppressor gene

A type of gene that regulates cell growth; when mutated, uncontrolled cell growth may occur, which can lead to cancer.

What is the role of Agrobacterium tumefaciens in the production of transgenic plants?

A. tumefaciens is used as a vector to move genes into plant cells.

What are the types of gametes that can be produced by an individual with the genotype AaBb?

AB, Ab, aB, ab

The _________ on each chromosome in the pair may be the same or different.

Alleles

Hybrid

An individual formed by mating between unlike forms, usually genetically differentiated populations or species

Model organism

An organism suitable for studying a specific trait, disease, or phenomenon, due to its short generation time, characterized genome, or similarity to humans; examples are a fly, fish, rodent or pig, whose biology is well known and accessible for laboratory studies.

Separation of the sister chromatids is a characteristic of which stage of miosis?

Anaphase

How can you tell the difference between an animal cell undergoing mitosis and a plant cell undergoing mitosis?

Animal cells have centrosomes and develop a contractile ring when splitting, whereas plant cells do NOT have centrosomes and form a cell plate when splitting.

Mutations in these genes may increase the likelihood of developing breast and ovarian cancers in women and some other cancers in women and men:

BRCA

Simplest form of cell division:

Binary Fission

What cells in our bodies do NOT undergo meiosis? Where are they located?

Body cells-- located in our organs, muscles, skin (Everywhere outside of sexually reproductive bits).

Prior to cell division, _________________________. This occurs during the "synthesis" or S phase of interphase.

Cells duplicate their genetic material.

_____________ are points in the cell cycle where cells stop to assess their progression.

Checkpoints

The color of corn kernels is controlled by two alleles (1 yellow and 1 white). A farmer mates yellow (yy) corn with white corn (ww) and produces corn (offspring; yw) that has equal numbers of yellow and white kernels. This is an example of:

Co-dominance

Describe three ways in which sexual reproduction contributes to genetic variation

Crossing over (in prophase I) Random assortment of chromosomes (in metaphase I) Random fusion of gametes from different parents. ________________ Mutation, recombination, and immigration of genes.

Compare DNA and RNA

DNA is a double-stranded molecule that has a long chain of nucleotides. RNA is a single-stranded molecule which has a shorter chain of nucleotides. ______________ DNA replicates on its own, it is self-replicating. RNA does not replicate on its own.

What is one factor that may cause a cell to pause in a phase of the cell cycle?

Damage to DNA. Cells will not continue through mitosis if their genetic material has been damaged. Damaged DNA that is transmitted to daughter cells may lead to cancer.

Genomics can be used in agriculture to:

Develop new varieties, solve food problems, and improve productivity & sustainability.

Human Germline cells are: (i.e Haploid/Diploid)

Diploid

Human Somatic cells are: (i.e Haploid/Diploid)

Diploid

What is an example of an organism likely to have the least complicated form of cell division?

Disease-causing bacterium. Bacteria are unicellular organisms that typically possess a single chromosome.

Tetrad (bivalent)

Each pair of chromosomes, called _____________, consists of four chromatids

Gametes are __________.

Eggs or sperm

The presence of one gene in Labrador retrievers influences coat color by affecting expression of another gene. This is one example of:

Epistasis

_________________ cells have a nuclear envelope and typically multiple chromosomes.

Eukaryotic

F2 generation

F1 generation comprise the second filial generation ______________ the result of a cross between two F1 individuals (from F1 generation)

What event occurs when an egg and sperm cell meet and combine to form one cell?

Fertilization

Meiosis produces _______________ daughter cells.

Four Haploid

When do checkpoints occur?

G1 phase, S phase, G2 phase, and M phase (mitosis).

A __________ only contains one allele for a given gene.

Gamete

What is the product of Meiosis?

Gametes (Sex cells)

Differentiate between genes and alleles

Gene is defined as a section of DNA that encodes for a certain trait. An allele is defined as a variant form of a gene. It determines an organism's genotype.

An organism's traits are determined by the specific combination of inherited _______________.

Genes

_____________ in the same location on homologous chromosomes carry information for the same traits.

Genes

Daughter cells

Genetically identical cells formed when a cell undergoes division by mitosis

What types of cells in our bodies undergo meiosis?Where are they located?

Germ cells-- located in ovaries/testes (Sexual reproductive cells)

Meiosis takes place in the:

Gonads

A sperm is: (i.e Haploid/Diploid)

Haploid

An egg is: (i.e Haploid/Diploid)

Haploid

in gel electrophoresis of DNA, the different bands in the final gel separate because the DNA molecules ____________.

Have different lengths

Homolog(ue)

Having the same typical structure and position; two anatomical structures or behavioral traits within different organisms which originated from a structure or trait of their common ancestral organism

_____________ can only make one kind of gamete.

Homozygotes

Describe the functions of mitosis for both unicellular and multicellular eukaryotes.

In unicellular organisms such as bacteria, mitosis is a type of asexual reproduction, making identical copies of a single cell. In multicellular organisms, mitosis produces more cells for growth and repair.

Crossing over occurs to:

Increase genetic variation

Pleiotropy refers to situation in which a single gene has _____________________, such as in the example of head shape and limb shape.

Influence over two or more different traits simultaneously

Protein signature

Information about all proteins that are made in blood, other body fluids, or tissues, at certain times. __________ may be used to find and diagnose a disease or condition and to see how well the body responds to treatment. Also called protein expression profile and proteomic profile.

Homologous pairs are ______________________________.

Inherited when each parent passes one chromosome on to offspring.

Replication of a cell's genetic material occurs during:

Interphase

What phase would you find replicated chromatin in?

Interphase

What phase would you find the Nuclear Envelope and Nucleus still intact?

Interphase

The genotype XXY corresponds to:

Klinefelter syndrome

Genetic engineering

Manipulation of an organism's genes by introducing, eliminating or rearranging specific genes using the methods of modern molecular biology

Describe the events that occur during each stage of meiosis.

Meiosis I Interphase: Prophase I: Chromosomes condense, homologous chromosomes synapse, crossing over takes place, nuclear envelope breaks down and mitotic spindle forms. ___________ Metaphase I: Homologous pairs of chromosomes line up on the metaphase plate. ___________ Anaphase I: Two chromosomes of each with two chromatids of each homologous pair separate and move toward opposite poles ___________ Telophase I: Chromosomes arrives at the spindle poles ___________ Cytokinesis: Cytoplasm divides to produce two cells, each having half the original number of chromosomes. __________ Interkinesis: In some cells the spindle breaks down, chromosomes relax and nuclear envelope re-forms, but no DNA synthesis takes place. ___________ Meiosis II Prophase II: Chromosomes condense, the spindle forms, and the nuclear envelope disintegrates. ____________ Metaphase II: Individual chromosomes line up on the metaphase plate ____________ Anaphase II: Sister chromatids separate, becoming individual chromosomes that migrate toward spindle poles ____________ Telophase II: Chromosomes arrive at spindle poles, the spindle breaks down and a nuclear envelope re-forms ____________ Cytokinesis: Cytoplasm divides.

The part of meiosis that is similar to mitosis is:

Meiosis II

What type of cells does meiosis began and end with? (i.e Haploid/Diploid)

Meiosis starts with diploid cells and ends with haploid cells.

Meiosis

Meiosis: A special form of cell division in which each daughter cell receives half the amount of DNA as the parent cell ________________________________ Meiosis I: a type of cell division unique to germ cells; the first meiotic division, begins with prophase I. During prophase I, the complex of DNA and protein known as chromatin condenses to form chromosomes. ________________________________ Meiosis II: similar to mitosis; a mitotic division of each of the haploid cells produced in meiosis I. During prophase II, the chromosomes condense, and a new set of spindle fibers forms. The chromosomes begin moving toward the equator of the cell.

_____________ is where homologous pairs are lined up in the middle of the cell.

Metaphase I

____________ is where replicated chromosomes are lined up in the middle of the cell.

Metaphase II

During _________, replicated chromosomes are split in two.

Mitosis

M phase

Mitosis; involves nuclear division and cytokinesis, where two identical daughter cells are produced; Mitosis involves prophase, prometaphase, metaphase, anaphase, and telophase. Finally, cytokinesis leads to cell division.

Bipolar attachment

Occurs during Metaphase; attachments of individual chromosomes or paired bivalents to the spindle.

Describe the role that oncogenes and mutated tumor suppressor genes play in cancer development.

Oncogenes are the main genes contributing to the conversion of normal cells to cancer cells and tumor-suppressive genes block the development of cancer; when mutated cell growth goes unchecked, which leads to the development and spread of cancerous cells.

Epistasis involves:

One gene influencing the phenotypic effect of another, such as with coat color in Labrador retrievers.

Imagine that you are performing a cross involving seed color in garden pea plants. What traits would you expect to observe in the F1 offspring if you cross true-breeding parents with green geeds and yellow seeds? Yellow seed color is dominant over green.

Only yellow seeds.

Describe the advantages and disadvantages of asexual reproduction

Organisms do not need to find a partner, this saves time and energy. Because offspring are identical to their parents none of the offspring will be less well adapted to their environment. _______________________________ Disadvantages: Because offspring are identical none of them will be any better adapted to their environment.

Explain how the polymerase chain reaction works.

PCR involves using short synthetic DNA fragments called primers to select a segment of the genome to be amplified, and then multiple rounds of DNA synthesis to amplify that segment.

A small circular DNA molecule that replicates independently of the chromosomal DNA in bacteria is called a:

Plasmid

The observation that individuals who are blind also have heart problems is an example of:

Pleiotropy

Complex traits whose patterns of inheritance cannot be predicted by Mendelian inheritance include:

Pleiotropy, Polygenic traits, Epistasis, and traits affected by the environment.

The technique used to rapidly increase the number of copies of specific regions of DNA for further analyses is called:

Polymerase chain reaction (PCR)

Explain how gel electrophoresis works.

Pores in the gel or matrix work like a sieve, allowing smaller molecules to move faster than larger molecules. To determine the size of the molecules in a sample, standards of known sizes are separated on the same gel and then compared to the sample.

What phase would you find unreplicated chromatin in?

Prior to Interphase or end of Telophase

What is accomplished through meiosis?

Production of egg and sperm cells and increased genetic diversity.

What kind of organism class is bacteria? (i.e Eukaryotic/Prokaryotic)

Prokaryotic (Lacks a Nuclear envelope)

What phase would the spindle occur in?

Prometaphase

What phase would you find replicated chromosomes occur in?

Prophase

Crossing over occurs in this phase:

Prophase I

What phase does the chiasma form?

Prophase I

Restriction enzymes are what type of biomolecule?

Protein

A gene that codes for a normal cell cycle regulator is called a(n):

Proto-oncogene

What occurs during S phase?

Replicated chromosomes are produced in preparation for mitosis.

What is the likely evolutionary advantage of sexual reproduction over asexual reproduction?

Sexual reproduction results in greater variation in the offspring.

What phase would the contractile ring (in animals) or cell plate (in plants) occur in?

Telophase

What phase would you find unreplicated chromosomes occur in?

Telophase

______________ is where haploid cells first appear.

Telophase I to Prophase II

Cells pause at critical points the the cell cycle to ensure:

That events are occurring properly.

The letters of possible combinations produced from a Punnett square represent:

The alleles in an offspring.

Describe the events that occur during each stage of the eukaryotic cell cycle, including mitosis.

The cell cycle is a four-stage process in which the cell increases in size (gap 1, or G1, stage), copies its DNA (synthesis, or S, stage), prepares to divide (gap 2, or G2, stage), and divides (mitosis, or M, stage). The stages G1, S, and G2 make up interphase, which accounts for the span between cell divisions. __________________________ During interphase, the cell grows and DNA is replicated. During the mitotic phase, the replicated DNA and cytoplasmic contents are separated and the cell divides.

What is one thing that occurs during interphase?

The cell expands in size-- the cell grows.

Proteome

The complete set of proteins made by an organism. Proteins are made in different amounts and at different times, depending on how they work, when they are needed, and how they interact with other proteins inside cells.

What is the most challenging issue facing genome sequencing?

The ethics of using information from genomes at the individual level.

Each reproduction event is the result of ______________, and therefore they are independent events.

The fusion of a single gamete from each of the two parents.

Two pea plants that are true-breeding for recessive white flowers are mated and their offspring analyzed. What is one true statement about this situation?

The gametes produced by the offspring will carry only one allele for this gene.

What's the relation between corresponding genes of a homologous pair of chromosomes?

The genes encode information for the same trait.

Ploidy level

The number of sets of chromosomes in a cell or an organism

Phenotype

The observable characteristics in an individual resulting from the expression of genes

Locus

The physical site or location of a specific gene on a chromosome

Metaphase plate

The plane in the equatorial region of the spindle where chromosomes align during cell division; equidistant from the two poles of a dividing cell

Heterozygous

The presence of two different alleles at a particular gene locus ______________ may include one normal allele and one mutated allele or two different mutated alleles

Homozygous

The presence of two identical alleles at a particular gene locus _____________ may include two normal alleles or two alleles that have the same variant.

In one statement, what is sexual reproduction?

The production of two haploid cells, one from each of two parents, and the subsequent fusion of two haploid cells to form a single, unique diploid cell.

A Punnett square is used to indicate _____________.

The separation of parental alleles into gametes and to show the possible combinations of alleles in offspring.

What is one thing that occurs during cell division?

The sister chromatids separate from one another.

Genomics

The study of the complete set of DNA (including all of its genes) in a person or other organism.

Proteomics

The study of the structure and function of proteins, including the way they work and interact with each other inside cells.

Linkage

The tendency for genes or segments of DNA closely positioned along a chromosome to segregate together at meiosis, and therefore be inherited together.

Describe the basic steps of DNA extraction.

There are five basic steps of DNA extraction that are consistent across all the possible DNA purification chemistries: 1) disruption of the cellular structure to create a lysate, 2) separation of the soluble DNA from cell debris and other insoluble material, 3) binding the DNA of interest to a purification matrix, 4) washing proteins and other contaminants away from the matrix and 5) elution of the DNA.

What is one reason why a cell might undergo mitosis?

To repair damaged tissues

Heterozygotes can make _______ kinds of gametes, each with equal probability of occurrence.

Two

Homologous chromosomes

Two chromosomes in a pair - normally one inherited from the mother and one from the father

What is the product of Mitosis?

Two identical daughter cells (each diploid)

A replicated chromosome consists of:

Two sister chromatids that are held together at the centromere.

Describe the base pairing rules.

Under normal circumstances, the nitrogen-containing bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The binding of these base pairs forms the structure of DNA .

What is the purpose of mitosis?

Used for asexual reproduction, organism growth, and repair of tissues.

Abnormalities in the number of X chromosomes tend to be milder than the same abnormalities in autosomes because of ___________.

X-inactivation

Spore

a cell that certain fungi, plants (moss, ferns), and bacteria produce; involved in reproduction. _____________________________ Can resist high temperatures, humidity, and other environmental conditions

Epistasis

a circumstance where the expression of one gene is modified (e.g., masked, inhibited or suppressed) by the expression of one or more other genes. ______________ the interaction between genes that influences a phenotype

Reciprocal cross

a concept of crossing a pair of parents with the sexes reversed, resulting in obtaining two reciprocal crosses of which one is another's reciprocal cross

Chiasma/chiasmata

a cross-shaped configuration of paired chromatids visible in the diplotene of meiotic prophase and considered the cytological equivalent of genetic crossing-over; _____________________ The point of contact between the homologous pair of chromosomes-- exchange of chromosomal segments takes place between non-sister chromatids of the homologous pairs.

Cancer

a disease caused by an uncontrolled division of abnormal cells in a part of the body.

Gene

a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.

Characteristic

a distinguishing quality, trait, or feature of an individual, thing, disorder, etc. It is often a distinctive mark, feature, attribute, or property of an individual or thing _______________ For example, the ability to camouflage

Septum

a dividing wall or membrane especially between bodily spaces or masses of soft tissue

Pharmacogenomics

a field of research that studies how a person's genes affect how he or she responds to medications

Incomplete dominance

a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype. It is also known as partial dominance

Physical map

a graphical representation of physical locations of landmarks or markers (such as genes, variants and other DNA sequences of interest) within a chromosome or genome

Dihybrid

a hybrid that is heterozygous for alleles of two different genes

Monohybrid

a hybrid that is heterozygous with respect to a specified gene

True breeding

a kind of breeding wherein the parents would produce offspring that would carry the same phenotype

Gel electrophoresis

a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size _____________ the molecules to be separated are pushed by an electrical field through a gel that contains small pores.

Polymerase chain reaction (PCR)

a laboratory technique for rapidly producing (amplifying) millions to billions of copies of a specific segment of DNA, which can then be studied in greater detail.

Vector

a living organism that transmits an infectious agent from an infected animal to a human or another animal.

Dihybrid Cross

a mating experiment between two organisms that are identically hybrid for two traits ______________ a cross between two individuals with two observed traits that are controlled by two distinct genes

Gamete

a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.

Centrioles

a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division.

Deoxyribonucleic acid (DNA)

a molecule that contains the biological instructions that make each species unique

Oncogene

a mutated gene that has the potential to cause cancer

Ribonucleic acid (RNA)

a nucleic acid present in all living cells that has structural similarities to DNA.

Origin of replication

a particular sequence in a genome at which replication is initiated

Carrier

a person who has one copy of a mutated (changed) disease-causing gene but has no symptoms or mild symptoms. ____________ can pass on the mutated gene to a biological child. If a child inherits one mutated copy of a gene from each parent, they will usually show symptoms of the disease or condition.

Genetically modified organism

a plant, animal or microbe in which one or more changes have been made to the genome, typically using high-tech genetic engineering, in an attempt to alter the characteristics of an organism.

Genetic recombination

a process by which pieces of DNA are broken and recombined to produce new combinations of alleles

Mitosis

a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells.

Contractile ring

a prominent structure during cytokinesis. It forms perpendicular to the axis of the spindle apparatus towards the end of telophase, in which sister chromatids are identically separated at the opposite sides of the spindle forming nuclei.

FtsZ protein

a protein encoded by the ftsZ gene that assembles into a ring at the future site of bacterial cell division (also called the Z ring)

Restriction enzymes

a protein isolated from bacteria that cleaves DNA sequences at sequence-specific sites

Mitotic spindle

a protein structure that divides the genetic material in a cell; necessary to equally divide the chromosomes in a parental cell into two daughter cells

Describe the structure of a duplicated chromosome.

a replicated chromosome has 2 sister chromatids. the centromere holds the 2 (identical) chromatids together

Genome-wide association studies

a research approach used to identify genomic variants that are statistically associated with a risk for a disease or a particular trait.

Life cycle

a series of changes in form that an organism undergoes, returning to the starting state.

Cell cycle

a series of events that takes place in a cell as it grows and divides.

Molecular cloning

a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms.

Plasmid

a small circular DNA molecule found in bacteria and some other microscopic organisms

Trait

a specific characteristic of an individual; can be determined by genes, environmental factors or by a combination of both; can be qualitative (such as eye color) or quantitative (such as height or blood pressure)

Gene therapy

a technique that modifies a person's genes to treat or cure disease.

Chromosomes

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Recessive

a trait that is expressed only when genotype is homozygous ___________ a trait that tends to be masked by other inherited traits, yet persists in a population among heterozygous genotypes.

Sex chromosome

a type of chromosome involved in sex determination (XX;XY)

Codominance

a type of inheritance in which two versions (alleles) of the same gene are expressed separately to yield different traits in an individual.

Discontinuous variation

abrupt variation in which there are few or no intermediate forms ____________ variation in phenotypic traits in which types are grouped into discrete categories with few or no intermediate phenotypes

Genetic diagnosis by genetic testing

also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. _______________ can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output.

Interkinesis

also known as interphase II, is a period of rest that certain species' cells experience between meiosis I and meiosis II. ___________________________ During which, no DNA replication occurs

Cleavage furrow

an indentation that appears in a cell's surface when the cell is preparing to divide

Hemizygous

an individual who has only one member of a chromosome pair or chromosome segment rather than the usual two __________ used to describe X-linked genes in males who have only one X chromosome.

Karyotype

an individual's complete set of chromosomes

Nucleoid region

an irregularly-shaped region within the cell of a prokaryote that contains all or most of the genetic material; it is not surrounded by a nuclear membrane

Centrosome

an organelle near the nucleus of a cell which contains the centrioles (in animal cells) and from which the spindle fibers develop in cell division.

Describe the process of binary fission.

an organism duplicates its genetic material, or deoxyribonucleic acid (DNA), and then divides into two parts (cytokinesis), with each new organism receiving one copy of DNA. _________________________________ Step 1- Replication of DNA. The bacterium uncoils and replicates its chromosome, essentially doubling its content. Step 2- Growth of a Cell. ... Step 3-Segregation of DNA. ... Step 4- Splitting of Cells.

Transgenic

an organism or cell whose genome has been altered by the introduction of one or more foreign DNA sequences from another species by artificial means.

Eukaryote

any cell or organism that possesses a clearly defined nucleus

Autosome

any chromosome that is not a sex chromosome.

Prokaryote

any organism that is chiefly characterized by a cell devoid of a well-defined (i.e., membrane-bound) nucleus

Binary fission

asexual reproduction by a separation of the body into two new bodies

Cell cycle Checkpoint

at which the cell examines internal and external cues and "decides" whether or not to move forward with the cell cycle.

Nucleic acid

biopolymers, macromolecules, essential to all known forms of life

Sex-linked

characteristics (or traits) that are influenced by genes carried on the sex chromosomes.

X-linked

characteristics or traits that are influenced by genes on the X chromosome

Genetic map

chromosome map of a species that shows the position of its known genes and/or markers relative to each other, rather than as specific physical points on each chromosome.

Diploid

containing two complete sets of chromosomes, one from each parent.

Duplicated chromosome

contains two identical double strand -DNA- molecules, the chromatids, that are joined at their centromere; a chromosome that has been copied.

Describe the process of reproductive cloning.

creating an animal that is genetically identical to a donor animal through somatic cell nuclear transfer. In reproductive cloning, the newly created embryo is placed back into the uterine environment where it can implant and develop. Dolly the sheep is perhaps the most well known example.

Genetic variation

describe the variation in the DNA sequence in each of our genomes ___________________________ Sources include: mutation and genetic recombination.

Recombinant

describes DNA, proteins, cells, or organisms that are made by combining genetic material from two different sources.

Law of independent assortment

describes how different genes independently separate from one another when reproductive cells develop.

Cell plate

develops at the midpoint between the two groups of chromosomes in a dividing cell

Describe the three life cycle strategies among sexually reproducing multicellular organisms. Compare these three life cycle strategies.

diploid-dominant (found in animals): Early in the development of the embryo, specialized diploid cells, called germ cells, are produced within the gonads, such as the testes and ovaries. Germ cells are capable of mitosis to perpetuate the cell line and meiosis to produce gametes. Once the haploid gametes are formed, they lose the ability to divide again. There is no multicellular haploid life stage. Fertilization occurs with the fusion of two gametes, usually from different individuals, restoring the diploid state ____________________ haploid-dominant (found in fungi and some algae): Most fungi and algae employ a life-cycle type in which the "body" of the organism—the ecologically important part of the life cycle—is haploid. The haploid cells that make up the tissues of the dominant multicellular stage are formed by mitosis. During sexual reproduction, specialized haploid cells from two individuals, designated the (+) and (−) mating types, join to form a diploid zygote. The zygote immediately undergoes meiosis to form four haploid cells called spores. Although haploid like the "parents," these spores contain a new genetic combination from two parents. The spores can remain dormant for various time periods. Eventually, when conditions are conducive, the spores form multicellular haploid structures by many rounds of mitosis ____________________ alternation of generations (two stages are apparent to different degrees depending on the group, as with plants and some algae): employed by some algae and all plants, is a blend of the haploid-dominant and diploid-dominant extremes. Species with alternation of generations have both haploid and diploid multicellular organisms as part of their life cycle. The haploid multicellular plants are called gametophytes, because they produce gametes from specialized cells. Meiosis is not directly involved in the production of gametes in this case, because the organism that produces the gametes is already a haploid. Fertilization between the gametes forms a diploid zygote. The zygote will undergo many rounds of mitosis and give rise to a diploid multicellular plant called a sporophyte. Specialized cells of the sporophyte will undergo meiosis and produce haploid spores. The spores will subsequently develop into the gametophytes

Non-recombinant

does not show any genetic recombination

Chromatid

each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.

Non-sister chromatids

either one of the two chromatids of paired homologous chromosomes __________________________ During Prophase I of Meiosis I, these chromatids of homologous chromosomes form chiasmata to exchange genetic material.

Monopolar attachment

established in haploid cells, indicating that homologous chromosomes are dispensable for its establishment; requires both mating pheromone signaling and inactivation of Pat1 kinase (a key negative regulator of meiosis)

Zygote

fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm)

Explain different applications of genomics and proteomics.

genomics is the study of the entire set of genes in the genome of a cell, and proteomics is the study of the entire set of proteins produced by the cell. ___________ Genomics provides an overview of the complete set of genetic instructions provided by the DNA, while transcriptomics looks into gene expression patterns. Proteomics studies dynamic protein products and their interactions, while metabolomics is also an intermediate step in understanding organism's entire metabolism.

Haploid

having a single set of unpaired chromosomes.

Aster

help to manipulate chromosomes during cell division to ensure that each daughter cell has the appropriate complement of chromosomes

Independent assortment

how different genes independently separate from one another when reproductive cells develop _____________________________ the alleles of two (or more) different genes get sorted into gametes independently of one another. ______________________________ refers to the behaviour of alleles of unlinked genes as a result of gamete production (meiosis)

Law of Dominance

in a heterozygote, one trait will conceal the presence of another trait for the same characteristic. Rather than both alleles contributing to a phenotype, the dominant allele will be expressed exclusively.

Gametophyte

in plants and certain algae, the sexual phase (or an individual representing the phase) in the alternation of generations—a phenomenon in which two distinct phases occur in the life history of the organism, each phase producing the other.

Describe the advantages and disadvantages of sexual reproduction.

introduces genetic variation into the species because the alleles that the mother and the father carry are mixed together in the offspring; can become better adapted to their environment. _______________________________ A disadvantage is that sexual reproduction takes longer than asexual reproduction; Have to find a mate to reproduce.

Kinetochore

large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters

Describe how linkage results in genotypic and phenotypic ratios that differ from expected ratios.

many possible explanations for deviations from expected ratios. Sometimes these deviations are due to sampling effects

Allele

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Asexual reproduction

one parent copies itself to form a genetically identical offspring

Law of Segregation

only one of the two gene copies present in an organism is distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is random.

Alternation of generations

plants alternate between two different life stages, or generations, in their life cycle; a haploid stage called gametophyte and a diploid stage called sporophyte

Recombinant proteins

proteins encoded by recombinant DNA that has been cloned in an expression vector that supports expression of the gene and translation of messenger RNA.

Describe uses of biotechnology in medicine and agriculture.

provides farmers with tools that can make production cheaper and more manageable. For example, some biotechnology crops can be engineered to tolerate specific herbicides, which make weed control simpler and more efficient. __________________ Some of the most recent uses of biological tech is work in genetic testing, drug treatments, and artificial tissue growth.

Model system

scientists' jargon for a particular species of animal that has been developed over many years to be experimentally powerful to answer particular questions.

Diploid-dominant life cycle

sexually-reproducing adults form haploid gametes from diploid germ cells. Fusion of the gametes gives rise to a fertilized egg cell, or zygote. The zygote will undergo multiple rounds of mitosis to produce a multicellular offspring

Explain what happens at each cell cycle checkpoint

surveillance mechanisms that monitor the order, integrity, and fidelity of the major events of the cell cycle. These include growth to the appropriate cell size, the replication and integrity of the chromosomes, and their accurate segregation at mitosis.

Random orientation

the behaviour of homologous pairs of chromosomes (metaphase I) or pairs of sister chromatids (metaphase II) in meiosis

Somatic cell

the cells in the body other than sperm and egg cells; Diploid

Cytokinesis

the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.

Apoptosis

the death of cells which occurs as a normal and controlled part of an organism's growth or development.

Reproductive cloning

the deliberate production of genetically identical individuals. Each newly produced individual is a clone of the original. Monozygotic (identical) twins are natural clones.

Sporophyte

the diploid multicellular individual or generation of a plant with alternation of generations that begins from a diploid zygote and produces haploid spores by meiotic division

Metagenomics

the direct genetic analysis of genomes contained with an environmental sample

Cell division

the division of a cell into two daughter cells with the same genetic material.

Crossing over

the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis)

Telophase

the final phase of cell division, between anaphase and interphase, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.

F1 generation

the first filial generation seeds/plants or animal offspring resulting from a cross-mating of distinctly different parental types.

Prophase

the first stage of cell division, before metaphase, during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears; In Meiosis I, this includes the reduction division.

Genotype

the genetic makeup of an organism; in other words, it describes an organism's complete set of genes

Genome

the haploid set of chromosomes in a gamete or microorganism, or in each cell of a multicellular organism; the complete set of genes or genetic material present in a cell or organism.

Monohybrid cross

the hybrid of two individuals with homozygous genotypes which result in the opposite phenotype for a certain genetic trait.

Biotechnology

the integration of natural sciences and engineering sciences in order to achieve the application of organisms, cells, parts thereof and molecular analogues for products and services.

Chromatin

the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.

Testcross

the mating of an organism whose genetic constitution is unknown with an organism whose entire genetic makeup for a trait is known, to determine which genes are carried by the former.

Haploid-dominant life cycle

the multicellular (or sometimes unicellular) haploid stage is the most obvious life stage and is often multicellular. In this type of life cycle, the single-celled zygote is the only diploid cell. Fungi and some algae have this type of life cycle.

Annealing

the pairing of a strand of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) with another complementary strand by hydrogen bonding to form a double-stranded helix.

Synapsis

the pairing of homologous chromosomes that occurs in prophase of the first meiotic division and during which crossing-over may occur.

P generation

the parental generation

Prometaphase

the phase of mitosis following prophase and preceding metaphase in eukaryotic somatic cells; nuclear membrane breaks apart into numerous "membrane vesicles," and the chromosomes inside form protein structures called kinetochores.

Recombination

the process by which DNA strands are broken and repaired, producing new combinations of alleles, occurs in nearly all multicellular organisms and has important implications for many evolutionary processes

Hybridization

the process in which two complementary single-stranded DNA and/or RNA molecules bond together to form a double-stranded molecule. The bonding is dependent on the appropriate base-pairing across the two single-stranded molecules. _________________ any of mixed origin or composition, or the combination of two or more different things

Cloning

the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction.

Sexual reproduction

the production of new organisms by the combination of genetic information of two individuals of different sexes. _________________________________________ In most species the genetic information is carried on chromosomes in the nucleus of reproductive cells called gametes, which then fuse to form a diploid zygote

Centromere

the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.

Dominant

the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the ____________ gene.

Interphase

the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis.

Identify four characteristics of homologous chromosomes.

the same gene sequence, loci (gene position), centromere location, and chromosomal length

Metaphase

the second stage of cell division, between prophase and anaphase, during which the chromosomes become attached to the spindle fibers.

Anaphase

the stage of meiotic or mitotic cell division in which the chromosomes move away from one another to opposite poles of the spindle.

Describe the G0 phase.

the stage wherein cells remain metabolically active but do not proliferate unless called to do so

Fertilization

the union of two gametes

Describe the blending concept of inheritance.

the value an individual has for a trait would be a blend of the values that the individual's parents have for that trait.

Sister chromatid

two identical chromatids that are formed by replication of a chromosome during the S phase of the cell cycle, are joined by a centromere, and segregate into separate daughter cells during anaphase.

Recombinant DNA

using enzymes and various laboratory techniques to manipulate and isolate DNA segments of interest. This method can be used to combine (or splice) DNA from different species or to create genes with new functions.

Continuous variation

variation in which a series of intermediate types connects the extremes