BIO Unit 3 Study Guide

What is the term for water movement across a membrane from a high concentration to a low concentration? filtration facilitated diffusion osmosis active transport none of the above

osmosis

Which of the following describes phospholipids in the plasmalemma? The lipid tails are hydrophilic. The lipid tails are hydrophobic. They can dissolve in water. The glycerol is hydrophilic. The phosphate heads are hydrophobic.

The lipid tails are hydrophobic

The general functions of the plasmalemma include, sensitivity to changes in the extracellular fluid. structural support of the cell. regulation of exchange of materials with the environment. physical isolation of the cell contents from the extracellular fluid. all of the above.

physical isolation of the cell contents from the extracellular fluid

The main component of the cytosol is ________. water sugars salts proteins

water

Which of the following statements is most correct regarding the intracellular chemical signals known as "second messengers"?Second messengers usually act to remove nitric oxide (NO) from the cell. Second messengers usually inactivate protein kinase enzymes. Cyclic AMP and calcium may be second messengers. Second messengers act through receptors called K-proteins.

Cyclic AMP and calcium may be second messengers.

An active process for transporting liquid across a plasmalemma is pinocytosis. exchange pumps. phagocytosis. bulk flow. none of the above.

pinocytosis.

Extracellular matrix is ________. not present in connective tissue composed of strands of actin protein the most abundant extracellular material a type of impermeable cell junction found in epithelia

the most abundant extracellular material

Communicating junctions are found in high quantities in the lungs eyes heart brain bones

heart

Processes involved in the movement of substances across a membrane at the expense of ATP are classified as diffusion. active transport. filtration. facilitated diffusion. osmosis.

active transport

Because the plasmalemma blocks some substances and allows others through, it is referred to as being, selectively permeable structurally rigid impermeable freely permeable. both A and C.

selectively permeable

Which of the following occurs during interphase? Chromosome duplication occurs. Sister chromatids separate. Chromatin becomes tightly coiled. The mitotic spindle forms.

Chromosome duplication occurs.

During metaphase, ________. centromeres divide chromosomes line up in the middle of the cell the nuclear envelope breaks up sister chromatids separate

chromosomes line up in the middle of the cell

Anaphase II is essentially the same as mitotic anaphase except that in anaphase II ________ and in mitotic anaphase ________. chromosomes line up double file in the middle of the cell...chromosomes line up single file in the middle of the cell the cells are haploid and sister chromatids separate...the cells have the same number of chromosomes as the original cell and sister chromatids separate crossing over occurs... crossing over does not occur the cells are diploid... the cells are haploid

the cells are haploid and sister chromatids separate...the cells have the same number of chromosomes as the original cell and sister chromatids separate

During metaphase I, ______ homologous chromosomes line up in the middle of the cell crossing over occurs the nuclear envelope breaks up sister chromatids separate and migrate to opposite poles

homologous chromosomes line up in the middle of the cell

Genetic variation is accomplished by all but one of the following. Choose the exception. crossing over the events of meiosis II the events of meiosis I independent assortment

the events of meiosis II

Which of the following occurs during prophase? The mitotic spindle begins to form. Sister chromatids separate. The nuclear envelope forms. Chromosomes line up on the midline of the cell.

The mitotic spindle begins to form.

Sexual reproduction in humans ________. produces a haploid individual produces an individual with 23 chromosomes combines two diploid gametes, producing a zygote allows a haploid sperm cell to fertilize a haploid egg cell

allows a haploid sperm cell to fertilize a haploid egg cell

A cell that completed the cell cycle without undergoing cytokinesis would ________. not have completed anaphase have its chromosomes lined up in the middle of the cell have less genetic material than it started with have two nuclei

have two nuclei

The CORRECT sequence of stages of mitosis is ________. anaphase, interphase, prophase, metaphase, telophase prophase, metaphase, anaphase, telophase interphase, prophase, metaphase, anaphase, telophase telophase, prophase, anaphase, metaphase

prophase, metaphase, anaphase, telophase

What is key to recognition of a trait whose expression is determined by the effects of two or more genes (polygenic inheritance)? The trait varies along a continuum in the population. Pleiotropy occurs. All of the alleles of the gene for that trait are equally expressed. A mating between a homozygous and a heterozygous individual produces more than the expected number of offspring expressing the dominant trait.

The trait varies along a continuum in the population.

To determine the phenotype of an individual who expresses a dominant trait, you would cross that individual with an individual who ________. is homozygous dominant for that trait homozygous recessive for that trait expresses the dominant trait is heterozygous for that trait

homozygous recessive for that trait

An individual with the genotype AaBb produces four different gametes in equal proportions. This is a demonstration of ________. Mendel's law of independent assortment linkage the chromosomal theory of inheritance Mendel's principle of segregation

Mendel's law of independent assortment

Round seeds ( R) are dominant to wrinkled seeds ( r), and yellow seeds ( Y) are dominant to green seeds ( y). What is the expected phenotypic ratio of a cross between an RrYy and an rryy individual? 3:1 1:1:1:1 1:2:1 9:3:3:1

1:1:1:1

An individual heterozygous for cystic fibrosis ________. will have children who are all carriers of cystic fibrosis is a carrier has cystic fibrosis cannot have children with cystic fibrosis

is a carrier

What is the key to the recognition of incomplete dominance? The trait exhibits a continuous distribution. The heterozygote expresses the phenotype of both homozygotes. The phenotype of the heterozygote falls between the phenotypes of the homozygotes. The alleles affect more than one trait.

The phenotype of the heterozygote falls between the phenotypes of the homozygotes.

What name is given to the specific location of a gene on a chromosome? phenotype genotype locus allele

locus

What is the key to the recognition of codominance? The phenotype of the heterozygote is intermediate between the phenotypes of the homozygotes. The heterozygote expresses the phenotype of both homozygotes. The alleles affect more than one trait. The trait exhibits a continuous distribution.

The heterozygote expresses the phenotype of both homozygotes.

What data or test would you seek to determine whether or not a trait is sex linked? blood test DNA sequence pedigree karyotype

pedigree

________ genes violate Mendel's principle of independent assortment. Codominant Pleiotropic Recessive Linked

Linked

Some hormones enter cells via endocytosis pincocytosis exocytosis recepter-mediated endocytosis

recepter-mediated endocytosis

Which of the following is a function of a plasma membrane protein? -circulating antibody - oxygen transport -molecular transport through the membrane -forms a lipid bilayer

molecular transport through the membrane

The extracellular fluid contains high amounts of sodium ions amino acid lipids potassium ions

sodium ions

Substances that enter the cell usually do so through the -peripheral proteins. -glycocalyx. -cholesterol. -integral proteins. -glycolipids.

integral proteins

how does oxygen pass through the plasmalemma? -across the membrane's lipid portion -always by active transport -always by passive processes -through membrane channels -both B&C

across the membrane's lipid portion

which of the following is an active process for material movement across a plasmalemma -bulk flow -endocytosis -osmosis -facilitated diffusion -diffusion

facilitated diffusion

which of the following is a characteristic seen in prophase 1 that does not occur in prophase 2 -crossing over occurs -spindle formation -chromosomes move to the middle of the cell -The number of chromosomes double

crossing over occurs

The chromosome of eukaryotic cells are found in the______. nucleolus Golgi apparatus centricle nucleus

nucleus

Chromatin consists of _____. protein only DNA only DNA and protein RNA and protein

DNA and protein

Crossing over during prophase I results in _____. -duplication recombination -genetic recombination -nondisjunction -reciprocal translocation

genetic recombination

Which of the following is the best description of the events of anaphase 1?

Homologous chromosomes randomly separate and migrate to opposite poles

Homologous chromosomes _____.

carry information for the same inherited characteristics