biology test 2

What is the phenotypic ratio for the offspring of a cross between a homozygous dominant ZZ and a homozygous recessive zz?

All dominant

Recessive X linked disorders...

Are more common in males than females

What dO the terms gene and allele have in common?

Both could refer to the same DNA sequence.

Homologous chromosomes...

Carry the same genes

Which of the following lists correctly identify some of the external defenses that your body uses to prevent infection?

Cilia, mucous membranes, and stomach acid

Using the DNA sequence TACGGTACCATTGCGCAA, determine which of the following choices is the complementary RNA molecule.

AUGCCAUGGUAACGCGUU

What can be found in chloroplasts and mitochondria that support the idea that they evolved from small, free-living prokaryotes that were engulfed?

DNA

No to gametes are exactly alike genetically, because...

Each gamete has a different combination of parental chromosomes and is the result of crossing over

If HIV infection doesn't directly kill patients, what does?

HIV impairs the immune system, and opportunistic infections kill the patients.

In humans, meiosis produces cells that are...

Haploid, called gametes

The members of a homologous pair of chromosomes...

Have the same genes but unique sets of alleles

How does meiosis generate genetic diversity?

Homologous chromosomes cross over during prophase one, during metaphase one, chromosomes align randomly

A Karyotype...

Is a picture of chromosomes arranged in pairs

How does the drug AZT slow the progression of HIV?

It inhibits the action of HIV reverse transcriptase

Why is the fluid-mosaic model ultimately the best depiction of the cell membrane?

It shows that the phospholipids and proteins within the layers are able to move.

Which of the following describes the ability of a single gene to cause multiple effects on an individuals phenotype?

Pleiotropy

Which of the following refers to the inheritance of traits that are controlled by two or more genes?

Polygenic

What materials are required for photosynthesis?

Water, carbon dioxide, sunlight

What is the major difference between dominant and recessive alleles of the same trait?

When both are present in the heterozygote only the dominant allele is expressed

What is a concentration gradient?

a difference in the density of substances from one location to another

The formation of new living organisms from nonliving chemicals is called ________.

biogenesis

Essential nutrients are those nutrients that the ________.

body cannot make for itself

What is the name of the outer coat of a virus?

capsid

The ________ nervous system is made up of the brain and spinal cord, whereas the ________ nervous system is composed of the nerves carry information into and out of the spinal cord and brain.

central; peripheral

What are the organelles of photosynthesis?

chloroplasts

Which of the following eukaryotic organelles are specific to plant cells?

chloroplasts

When the cell's DNA is condensed, it is called ________, and it consists of most of the cell's DNA and some specialized proteins.

chromosomes

Individual free-living cells that physically associate with one another form ________.

colonies

_______ is the transfer of DNA between two bacterial cells via a physical bridge.

conjugation

what is the function of reverse transcriptase?

converts information from RNA to DNA

What intracellular structure helps animal cells to maintain their shape?

cytoskeleton

What is the watery liquid surrounding the organelles in the cell?

cytosol

The alimentary canal is part of the ________ system.

digestive

The process of moving material into a cell by the membrane forming a pocket around the substance and then pinching the membrane inward is called ________.

endocytosis

Humans have ________ in which the bones are associated with the soft tissues and are found inside the body.

endoskeleton

What type of cell has membrane-bound organelles, can be unicellular or multicellular, and is structurally complex?

eukaryote

________ cells are larger and evolved after ________ cells.

eukaryotic; prokaryotic

What is it called when carrier molecules are used to move molecules down a concentration gradient?

facilitated diffusion

The ________ trimester is the most sensitive time in fetal development, because this is when most organs are formed

first

A long extension that can propel a cell through a liquid medium is known as ________.

flagellum

In a punnets square, what do the letters outside the little boxes represent?

gamete genotypes

Organelles made up of a series of membrane sacs that organize and package proteins for transport are called the ________.

golgi apparatus

If an organism is transgenic, then it ________.

has one or more genes from another species of organism

A carrier of a human genetic disorder is

heterozygous with one copy of the normal alleles and one copy of the disease causing allele

What type of joint permits movement in a single plane?

hinge

The phosphate head of the phospholipid is ________, whereas the fatty acid tails are ________.

hydrophilic; hydrophobic

The ________ is the organ system primarily responsible for protecting your body from infectious diseases.

immune system

Where are photoreceptor cells found in the eye?

in the retina

All prokaryotes have which of the following in common?

lack a true nucleus

________ are a type of fibrous connective tissue that holds bones together at joints.

ligaments

In the ________, viruses multiply in the host cell and then burst out; in the ________, the viral DNA inserts itself into the host cell DNA and remains dormant, replicating itself and eventually removing itself from the bacterial DNA.

lytic cycle; lysogenic cycle

The polymerase chain reaction (PCR) is an important technique in biotechnology, because it allows researchers to ________.

make many copies of a specific DNA sequence

Most homeostatic systems rely on ________ feedback.

negative

The ________ are the functional units of the kidney that filter the blood and form the urine.

nephrons

Which body system is responsible for communication and coordination throughout your body?

nervous

The DNA in prokaryotic cells is ________.

not contained in any sub cellular structure

What area in the nucleus is responsible for assembling ribosomal RNA in eukaryotic cells?

nucleolus

Eukaryotic DNA is located in the ________, and its message reaches the ribosome by passing through the ________.

nucleus, nuclear pores

What is a biofilm?

organized colony of prokaryotes that adhere to a surface

An agent that causes disease is called a ________.

pathogen

Bacteria are __________.

prokaryotes

________ cells contain plasmids, ________ cells do not.

prokaryotic; eukaryotic

All eukaryotes that do not belong to the plant, animal, or fungus kingdoms are classified as _______.

protists

The simplest of the eukaryotes are __________.

protists

The human cardiovascular system can be divided into two circuits: the ________ circuit transports blood between the heart and lungs and the ________ circuit transports blood between the heart and the rest of the body.

pulmonary; systemic

Homeostasis is disrupted when an endocrine gland produces ________ hormone product.

too much or too little

What occurs in the nucleus and results in the production of RNA from DNA?

transcription

The information contained in RNA is used to produce proteins in the process of ________.

translation

Successful DNA replication results in ________.

two double helix molecules, each half parental DNA and half newly synthesized DNA

The _______ system provides osmoregulation in your body.

urinary

Which organelles are small bubbles of membrane that transport materials throughout the cell?

vesicles

Small, circular, single-stranded RNA molecules capable of infecting and causing disease in plants but unable to encode proteins are known as ________.

viroids

A fertilized egg is called ________.

zygote

What is a bacteriophage?

A virus that infects bacteria

If a cell has 30 chromosomes before mitosis how many does each daughter cell have afterward

30

A human somatic (body) cell has... chromosomes

46

According to the principle of segregation, the gametes of a heterozygous individual will contain...

50% dominant and 50% recessive alleles

Which of the following allows sexual reproduction to occur generation after generation?

Meiosis

Diploid cells become haploid during...

Meiosis one

Which of the following terms describes a failure of chromosomes to sort properly during meiosis?

Nondisjunction

Segregation

Occurs when alleles for the same trait separate during gamete formation

The sex of a human fetus is determined by the ...

Sex chromosome found in the sperm

In meiosis two...

Sister chromatids are separated into different daughter cells

What is the difference between stem cells and other body cells?

Stem cells are adaptable and can give rise to other cell types

A gene is...

The unit of inheritance that codes for proteins or RNA

Photosynthetic protists capable of producing their own food from sunlight are _______.

algae

Which of the following are protists?

algae

These single-celled, very flexible protists use pseudopodia for movement and feeding.

amoebas

What is a prion?

an infectious protein

Two hormones that counteract one another's actions in a feedback circuit are said to be ________ hormones

antagonistic

_______ are prokaryotes that exist in extreme conditions.

archaea

________ are blood vessels that carry blood away from the heart.

arteries

Hormones can travel through the blood and not affect all tissues; only cells possessing ________ sites for that particular hormone are affected, and these cells are called ________ cells.

receptor; target

Where is reverse transcriptase found?

retroviruses

What is the structural difference between rough endoplasmic reticulum (ER) and smooth ER?

rough ER had ribosomes but smooth ER doesn't

Large, multicellular marine algae are also known as ________.

seaweeds

Sites within the human genome where a short nucleotide sequences is repeated many times in a row are known as ________.

short tandem repeats

Which of the following is a site for lipid synthesis?

smooth ER

What property of colonies contributed most toward evolution of multicellular organisms?

specialization