Biology exam 2

Karyotype

an image of an individual diploid set of chromosomes

transgenic organism

an organism that contains at least one gene from another species

What are the two kinds of base pairing?

A to T G to C

How does epigenetics break Mendel's laws

According to Mendel's laws, the effects of our environment are not passed on to the next generation.

Every _______ cell contains every gene

Somatic

Animal viruses have a membranous outer envelope and projecting __________

Spikes of Glycoprotein

The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____.

Sticky ends

A geneticists finds that a particular mutation has no effect on the polypeptide encoded by the gene. This mutation probably involves?

Substitution of one nucleotide

What stage of mitosis is essentially the opposite of prophase in terms of changes within the nucleus?

Telophase

An old DNA strand is used as a _____ for the assembly of a new DNA strand.

Template

gene cloning

The production of multiple copies of a gene.

Gene cloning

The production of multiple identical copies of a gene.

What is triplet code?

The standard version of the genetic code, in which a sequence of 3 nucleotides in a DNA/RNA molecule codes for a specific amino acid in protein synthesis.

Genomics

The study of complete sets of genes (genomes).

A gene that is located on a sex chromosome (X or Y chromosome) is _________

sex-linked gene

nearly universal

shared by all organisms

Pedigree

shows the inheritance of a trait in a family through multiple generations

Prions

infectious proteins that cause degenerative brain diseases in animals

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

The flow of information in a cell proceeds __________.

DNA to RNA to protein

If an intestinal cell in a grasshopper contains 24 chromosomes, then a grasshopper sperm cell contains ___ chromosomes.

12

Synapsis occurs during _____

Prophase I

What are the two main components of cellular membranes?

Proteins and Phospholipids

The action of helicase creates _____.

replication forks and replication bubbles

DNA replication occurs at an unbelievably fast rate. Once replication is complete, we can expect to find a _____ number of mistakes.

Small

Restriction enzymes

cut DNA at specific nucleotide sequences

Virus

"gene in a box" - an infectious particle

How do mutations affect an organism?

-They may cause the development of a disease-causing allele -They may cause the development of a more beneficial allele - They, in some cases, may have no noticeable affect

What are the two basic types of reproductive cycles?

1. Lytic Cycle- The process of lysis, which occurs when a virus has infected a cell, replicated new virus particles, and bursts through the cell membrane. 2.Lysogenic Cycle- A method by which a virus can replicate its DNA using a host cell.

What are the three processes that contribute to the emergence of viral diseases?

1. Mutation- RNA viruses mutate rapidly 2. Contact between species- viruses from other animals spread to humans 3. Spread from isolated human populations to larger human populations.

what do viruses consists of?

1. Nucleic Acid 2. Protein Coat called a capsid 3. A membrane envelope (sometimes)

What are the characteristics of a genetic code?

1. Three nucleotides specify one amino acid 2. 61 codons correspond to amino acids 3. AUG codes for methionine and signals the start of transcription 4. 3 "stop" codons signal the end of translation

What are the possible outcomes of nucleotide substitutions?

1.Silent mutation- No effect 2.Missense mutation- change in the amino acid coding 3.Nonsense mutation- creates a stop codon

DNA in one human cell is about ............ long?

2 meters (6.5 ft)

How many nucleotides are needed to code for an amino acid

3

How many parts of genetic code are there?

4

How many codons can be possible?

64

What does phage attach to?

A cell

Mutagens

A chemical or physical agent that interacts with DNA and causes a mutation.

What does it mean to say that genes are turned on or off?

A gene that is turned ON is being TRANSCRIBED into mRNA, and that message is being TRANSLATED into specific proteins. (DNA -> RNA -> Protein)

What do viruses rely on to reproduce?

A host cell

DNA profiling

A procedure that analyzes DNA fragments to determine whether they come from a specific individual.

polymers chain reaction (PCR)

Allows identification of pathogenic organisms that are difficult to culture by detecting their DNA or RNA.

Plasmids

Circular piece of DNA that comes from a virus

what specific term refers to a protein coat enclosing a viral genome?

Capsid

Name two structures found in both Prokaryotic and Eukaryotic cells.

Cell Wall and Cytoplasm

What genetically modified organisms make the majority of human insulin for medical purposes?

Bacteria

DNA is the

Basis of life's unity

Genetically modified (gmo)

Crops that have had their DNA altered through genetic engineering to grow faster or bigger, or more drought resistant, etc.

Every cell in your body has the same _____ as the zygote

DNA

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments?

DNA polymerase can assemble DNA only in the 5' to 3' direction

Recombinant DNA

DNA produced by combining DNA from different sources

True/False: There are cures for most viral diseases

False- There are NO cures for most viral diseases

True/False: Are viruses considered alive?

False- They are NOT considered alive

True/False: Are viruses cellular?

False- they are NOT cellular

What has DNA profiling transformed?

Forensics

What type of mutation that can be formed in any type of cell that can be passed down to offspring?

Gametes

Gametes

Haploid cells, derive from germ cells, immature reproductive cells

spikes of glycoproteins

Helps the virus enter and leave the host cell

Prions

Infectious particles that cause disease in animals

Viroids

Infectious particles that cause disease in plants

Short segments of newly synthesized DNA are joined into a continuous strand by _____.

Ligase

sexaul reproduction

Make unique individuals, mixes alleles from parent, fusion of gametes, meiosis

Asexual reproduction

Makes clones, uses mitosis

Gene regulations

Mechanisms that turn on certain genes while other genes remain turned off

................ is the spread of cancer cells from their site of origin to other sites in the body.

Metastasis

Polygenic Inheritance

Multiple genes affect a trait

Codons

Non overlapping Three-base "words"

what are the two kinds of mutations?

Nucleotide substitutions (base substitution) Nucleotide deletions or insertions (frame- shifts)

A supplemental appendix is to a book as a ____________ is to a bacterial chromosome.

Plasmid

Translation

Process by which mRNA is decoded and a protein is produced

What term refers to viral DNA that has been incorporated into host cell DNA?

Prophage

Some infectious agents are made only of ___ or protein

RNA

What do most plant and animal viruses have?

RNA rather than DNA

What food crop is being genetically engineered to produce beta-carotene, which can potentially help people with Vitamin-A deficient diets?

Rice

What is a double helix?

Shape of DNA

Gel electrophoresis separates pieces of DNA based on _________.

Size

Vector

The gene to be cloned

gene expression

The process by which genetic information flows from genes to proteins

Diploid number

The total number of chromosomes in a diploid cell.

Enzymes for DNA polymerases

They make the covalent bonds between the nucleotides of a new DNA strand and can help repair DNA that has been damaged.

True or False Covid-19 is considered to be a zoonotic disease

True

True or False: During the COVID-19 pandemic, SARS-Cov-2 was considered an emerging virus.

True

True/False: Viruses are LESS complex than a cell

True

True/False: Viruses are used to study the functions of DNA

True

True/False: Viruses cannot reproduce on their own

True

Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes?

Use the polymerase chain reaction.

Every cell in your body was produced through successive rounds of mitosis starting from the _______

Zygote

Which of the following is an example of a transgenic organism?

a bacterium with human gene for producing insulin

unambiguous

a codon for one amino acid does not code for any other amino acid

Homologous chromosomes migrate to opposite poles during _____.

anaphase I

During _____ sister chromatids separate.

anaphase II

Linked genes are genes that __________.

are on the same chromosome

Replication of chromosomal DNA occurs __________.

before a cell divides

A .......... is a lump of abnormal cells that, although growing out of control, remains at its original site.

benign tumor

An individual with a malignant tumor is said to have

cancer

What is each amino acid specified by?

codon

without punctuation

codons are adjacent to each other with no gaps in between

Which characteristic of living cells do viruses lack

complete replication apparatus

Variation within DNA's nucleotide sequence is the foundation of life's diversity; defines ___ and distinguishes ___

defines SPECIES and distinguishes INDIVIDUALS

The main goal of the Human Genome Project was to __________.

determine the nucleotide sequence of the entire human genome and map all the human genes

Lysomes are responsible for

digestion of organic matter inside the cell

Diabetes

disease caused by insulin deficiency

New molecules of DNA are synthesized by copying the genetic sequence of another molecule of DNA, which we call the template, so that __________.

during cell division daughter cells are genetically identical to the mother cell

After DNA replication is completed, _____.

each new DNA double helix consists of one old DNA strand and one new DNA strand

DNA testing (profiling) has been used to determine the guilt or innocence of crime suspects. This works because __________.

every person has a unique DNA sequence

Mutation is the raw material for

evolution

Meiosis II typically produces _____ cells, each of which is _____.

four ... haploid

GgTt pea plants can produce __________ type(s) of gamete(s), and a ggtt plant can produce __________ type(s) of gamete(s).

four ... one

Insulin

hormone that regulates glucose, produced by pancreas

In general, the frequency with which crossing over occurs between two linked genes depends on __________

how far apart they are on the chromosome

What holds the two strands of DNA together?

hydrogen bonds

Which processes lead to most genetic variation in sexually reproducing organisms?

independent orientation of chromosomes in meiosis random fertilization crossing over

Human gene therapy

intended to treat disease by introducing genes into an afflicted person

what can mutations involve?

large chromosomal regions or just a single nucleotide pair

In humans, the __________ determines the sex of the offspring because __________

male ... the male can contribute either an X or a Y chromosome

A ................ is an abnormally growing mass of cells that is actively spreading through the body

malignant tumor

Genetic engineering

manipulating genes for practical purposes

genetic engineering

manipulating the genes of organisms to make new products

Sexual reproduction requires the cellular process of __________ followed by __________.

meiosis ... fertilization

During _____ chromosomes align single file along the equator of a haploid cell.

metaphase II

DNA Technology

modern techniques to study and manipulate genetic material

redundant

more than one codon for some amino acids

The ABO blood group in humans is an example of __________ producing four phenotypes

multiple alleles

frameshift mutation

mutation that involves the insertion or deletion of a nucleotide in the DNA sequence

Most cancers are caused by

mutations

Transgenic organisms

organism that contains genes from other organisms

The physical traits of an organism are called its _____.

phenotype

During _____ a spindle forms in a haploid cell.

prophase II

Histones

protein molecules that help organize the nucleus

nucleotide substitution

replacement of one nucleotide with another

Pleiotropy

single gene controls one trait

What do gene regulations allow?

specialization of cells within the body

A geneticist finds that a particular mutation has no effect on the polypeptide encoded by the gene. This mutation probably involves

substitution of one nucleotide

What are the backbones of DNA?

sugar and phosphate

At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.

telophase I

At the end of _____ and cytokinesis there are four haploid cells.

telophase II

What does DNA replication ensure?

that all the somatic cells in a multicellular organism carry the same genetic information

Biotechnology

the manipulation of organisms or their components to make useful products

The information carried by a DNA molecule is in __________

the order of the nucleotides in the molecule

The process of accurately amplifying a sample of DNA is called

the polymerase chain reaction

Mutagenesis is

the production of mutations

Mutagensis

the production of mutations

In a DNA double helix, adenine pairs with ....... and guanine pairs with ........?

thymine, cytosine

Meiosis I produces _____ cells, each of which is ____

two ... haploid

Emerging Viruses

viruses that appear suddenly or are new to medical scientists

The most common phenotype in a natural population is referred to as the __________.

wild type