Final Exam Practice Questions for BIO 111

Function of a protein kinase

To add phosphate groups onto proteins

Property of most ligands for intracellular receptors

They are lipid-soluble

Process generating large intracellular response from cell surface receptors

signal amplification

Bacterial cell division process

binary fission

Two copies of each type of chromosome in normal somatic cells

homologous chromosomes

Number of chromosomes if there are 32 sister chromatids

16

Sequence of events in a typical eukaryotic cell cycle

G1 to S to G2 to mitosis to cytokinesis

Portion of the cell cycle with invisible chromosomes

interphase

Importance of chromosomes aligning on the metaphase plate

If they cannot, it suggests that they aren't properly attached to the spindle microtubules, and thus won't separate properly during anaphase.

Proteins regulating the eukaryotic cell cycle

Cyclins

Process of nuclear division reducing chromosomes from 2 sets to 1 set

Meiosis

Process reducing chromosomes in half in life cycles alternating between haploid and diploid stages

meiosis

Genetic exchange process during prophase I of meiosis

crossing over

Rounds of nuclear division in meiosis

two

Cell produced by fusion of egg and sperm

zygote

germ-line cells

Cells that will eventually undergo meiosis to produce gametes.

prophase I

The stage during which crossing over between homologous chromosomes takes place.

independent assortment

The way one pair of homologues lines up along the metaphase plate does not affect how any other pair lines up.

mitosis

The process that does not increase genetic variation.

Down's syndrome

Aneuploid condition most likely resulting from failure of 1 homologous pair to segregate during meiosis.

genes

Mendel's heredity 'factors' in modern terminology.

phenotype

The observable expression of the genes present in an organism.

alleles

Alternate forms of the same gene.

3 yellow: 1 green

The approximate phenotypic ratio among the F2 generation in Mendel's experiments on seed color.

heterozygous

The resulting offspring when fertilization involves two gametes that contain different alleles of a given gene.

test cross

The type of cross used to determine if an individual with the dominant form of a trait is homozygous or heterozygous.

purple flowers, tall

The phenotype of a plant with the genotype PpTt.

non-homologous chromosomes

Different pairs that segregate independently of each other according to Mendel's Principle of Independent Assortment.

autosomes

The 22 pairs of homologous chromosomes found in both males and females.

21

The chromosome most likely to result in survival until adulthood in individuals with trisomy.

amniocentesis

A procedure that is normally used for diagnosis of genetic disorders.

random fertilization

One of the processes that increases genetic variation.

independent assortment

The segregation of chromosomes during meiosis I that is independent of their segregation during meiosis II.

mutation

A process that increases genetic variation.

haploid

The term for gametes that contain only one set of chromosomes.

dihybrid

The term for offspring resulting from a cross involving two different traits.

reciprocal cross

A cross that involves switching the traits of the parents.

karyotype

A display of the complete set of chromosomes in an organism.

cofactors

Substances that assist enzymes in catalyzing reactions.

XO genotype

An individual with a genotype of XO would be female because each cell lacks a Y chromosome.

Male humans

Male humans have an X and Y sex chromosome.

Female humans

Females have two X chromosomes.

Bird sex chromosomes

In birds, the female has a Z and a W sex chromosome, while the male has two Z chromosomes.

Gender determination in humans and birds

In humans, the male determines the gender of the offspring, and in birds the female determines the gender.

Barr bodies in females

A normal human female contains 1 Barr body in each diploid cell.

Watson & Crick DNA model

Watson & Crick developed a model of DNA in which the two strands twist into the shape of a double helix.

Strands of DNA molecule

The two strands of a DNA molecule are complementary to each other.

DNA replication method

The method of DNA replication, where each original strand is used as a template to build a new strand, is called the semiconservative method.

Enzyme adding nucleotides

The enzyme that adds new nucleotides to the end of a growing strand is polymerase.

Chargaff's rules

Chargaff's rules for the pairing of nitrogen bases is A = T and G = C.

Lagging strand replication

The lagging strand is replicated with a series of Okazaki fragments and that is why its synthesis is considered to be discontinuous.

False statement about DNA replication

The newly synthesized DNA is packaged into one nucleus, and the original DNA is packaged into another nucleus.

Percentage of G in DNA

If 14% of the nucleotides from a DNA molecule contain the base T, then 36% will contain the base G.

Enzyme unwinding DNA

During replication, the enzyme that unwinds the DNA double helix is DNA helicase.

Eukaryotic DNA replication speed

Eukaryotic organisms speed up the process of DNA replication by using multiple origins of replication on each chromosome.

X-ray diffraction of DNA

Franklin provided X-ray diffraction photographs of purified DNA fibers that suggested a helical structure with a consistent diameter of about 2 nm and a complete helical turn every 3.4 nm.

Rungs of the DNA ladder

In the DNA double helix, the rungs or steps of the ladder are made up of nitrogenous bases.

DNA

A molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms.

Proteins

Molecules composed of amino acids that perform a vast array of functions within living organisms.

Gene expression

The process by which information from a gene is used to synthesize a functional gene product, typically proteins.

Transcription

The first phase of gene expression where a segment of DNA is copied into RNA.

Translation

The process in which ribosomes synthesize proteins using the mRNA transcript.

Promoter

A segment of DNA where RNA polymerase binds to initiate transcription.

Coding strand

The strand of DNA that has the same sequence as the mRNA transcript.

Codons

Blocks of information in the genetic code, each corresponding to one amino acid.

Splicing

The process of removing introns from the primary mRNA transcript and joining exons together.

Ribosomes

Cellular structures that synthesize proteins by translating mRNA.

Eukaryotic transcription location

Transcription occurs inside the nucleus.

Unique mRNA codons

64 unique mRNA codons can be constructed from the four different RNA nucleotides.

Stop codons

Codons that signal the termination of translation.

Peptide bond

The bond that forms between a newly added amino acid and the previous amino acid in a polypeptide chain.

Pre-mRNA processing

Involves the addition of a 5' cap, addition of a 3' poly-A tail, and splicing by the spliceosome.

Flow of gene expression

The correct flow is DNA→ RNA→ proteins.

3' poly-A tail

Attached to mRNA to protect it from degradation and assist in translation.

Homeostasis

The maintenance of a constant environment in a cell.

mRNA stability

Eukaryotic cell mRNA transcripts can remain in the cell for hours because they are stable.

Enhancers

Binding sites for specific transcription factors that increase the likelihood of transcription.

Structural motifs

Shapes that DNA-binding proteins use to fit into the DNA major groove.

Lac operon

A regulatory system important to bacteria for controlling the metabolism of lactose.

Repressor

A protein that regulates transcription by binding to the operator.