BIO 123 FINAL EXAM

Comprehensive vocabulary flashcards covering key biological terms, mechanisms, and structures across Chapters 7, 8, 9, and 10 of Campbell Biology: Concepts & Connections (10th Edition).

Photoautotrophs

Organisms—including plants, algae, and protists and bacteria—that convert light energy into food and serve as producers for heterotrophic organisms.

ribosomes

structures in the cytoplasm that coordinate function of MRNA AND TRNA and catalyze the synthesis of polypeptides

made of Ribosomal RNA (RNA +proteins

binding sites for ribosomes in the translation phase

4 TRNAS and MRNA

A site- aminoacyl site where the TRNA will be

P site- peptidyl site

E site- Exit

frame shift mutation

insertion and deletion

shifts the entire reading frame for the rest of the genetic code by adding or removing bases in a non multiple of three

a match between a TRNA and amino acid

done by the enzyme aminoacyl TRNA synthetase

Machinery for Translation

MRNA Ribosome

RNA + Proteins

2 subunits 3 products

large subunit small subunit

E exit site

P pepityl site

A aminocyl site

mutations

changes in the DNA sequence that can affect genetic information. They can be caused by various factors, including errors during DNA replication or environmental influences.

mutagens

deletion

insertion,

transfer RNA

serves as interperter between amino acids and mRNA

Messenger RNA

Kind of RNA that encodes amino acids sequences, it conveys genetic messages from DNA to the translation machinery of the cell

DNA replication

replication starts w/ the sep of dna strands

enzyme then use each strand as a template to assemble new nucleotides into a complementary strand

proceeds in two directions at many sites simultaneously

moves 5’ to 3’

DNA polymerase

this enzyme attaches and the cell synthesizes one daughter strand as a continuous strand (LEADING strand)

3 prime

end of a DNA molecule where nucleotides are added during replication.

nucleotide is composed of

a nitrogenous base, a sugar, and a phosphate group.

translation

ribosome attaches to MRNA, translates message into specific polypeptide aided by transfer RNA (tRNA)

a new DNA strand can elongate-

synthesis of proteins under the direction of RNA occurs in the Cytosol

5 prime

end of a DNA molecule where synthesis starts during replication.

attached to a phosphate group

nucleotides are joined together by

phosphodiester bonds, forming a sugar-phosphate backbone.

1 start codon

-MET AUG

3 stop codon

UAG

UAA

UGA

genetic code

is ambiguous

each codon is specific for only one amino acid and is universal across almost all organisms.

Chlorophyll

A light-absorbing pigment located in chloroplasts that plays a central role in converting solar energy to chemical energy.

Stroma

The thick fluid enclosed by the double membrane of a chloroplast, surrounding the thylakoid membranes, where the Calvin cycle takes place.

Thylakoids

Interconnected membranous sacs inside a chloroplast where light reactions take place.

transcription

produces genetic messeages in RNA form:

nucleus DNA helix unzips, and RNA nucleotides lines up and RNA polymerase (moves in 5’ to 3’) joins them along the growing RNA strand, creating a complementary, antiparallel copy of the DNA template. ( direction 3’ to 5’)

elongation

phase of transcription refers to the process through which ribonucleotides are added to the growing RNA chain

Termination RNA polymerase

adds RNA nucleotides unitl it reach a sequence of DNA called a terminator, signaling the end of transcription and resulting in the release of the newly synthesized RNA molecule.

P680

The reaction-center chlorophyll a molecule of Photosystem II (PS II) that absorbs light best at this wavelength of

P700

The reaction-center chlorophyll a molecule of Photosystem I (PS I) that absorbs light best at a wavelength of

Photophosphorylation

The production of $ATP$ in plants using energy derived from light to establish a proton ($H^+$) gradient across the thylakoid membrane.

Calvin Cycle

The second stage of photosynthesis in the stroma that uses $ATP$, $NADPH$, and $CO_2$ to construct high-energy sugar molecules like $G3P$.

C3 Plants

Plants that use the Calvin cycle directly for initial carbon fixation, forming a 3-carbon compound as the first product.

a decrease or drop of Co2 +rise in O2 stomata close divert the Calvin cycle in photorespiration

C4 Plants

Plants (such as sugarcane) + maize adapted to hot, dry climates that first fix CO2​ into 4-carbon compounds that provide Co2 to C.C even when stomata close on hot dry days to prevent loss of water

CAM Plants

Plants (such as cacti and pineapple) adapted to dry environments that open stomata at night to fix CO2 into 4-carbon compounds, releasing CO2 during the day for the Calvin cycle.

Binary Fission

A form of asexual reproduction in typical prokaryotes where a single cell replicates its circular chromosome and divides in half into two daughter cells.

Chromatin

Thin, loosely packed fibers composed of DNA and associated proteins found in eukaryotic cell nuclei when the cell is not dividing.

Sister Chromatids

Two identical copies of a duplicated chromosome joined closely along their lengths, particularly at the centromere.

Centromere

The narrow region where two sister chromatids of a duplicated chromosome are held together most tightly.

Interphase

The stage of the cell cycle during which the cell grows, synthesizes DNA, and prepares for division, consisting of G1,G1​, S, and G2G2​ phases.

part of the cell cycle wehn the cell is not dividing

Cleavage Furrow

A shallow constriction formed on the cell surface of animal cells by a contracting ring of microfilaments during cytokinesis.

Cell Plate

A double membrane structure formed across the midline of a dividing plant cell by the fusion of vesicles containing cell wall material during cytokinesis.

(Contact Inhibition)

The phenomenon in which normal cultured cells stop dividing once they come into contact with one another, forming a single monolayer.

Homologous Chromosomes

A pair of matching chromosomes of the same length, centromere position, and gene loci, carrying genes for the same traits.

Diploid

Containing two complete sets of homologous chromosomes (2n2n), one set inherited from each parent.

Haploid Cell

Containing a single set of chromosomes (nn), such as gametes.

Nondisjunction

An accident of meiosis or mitosis in which a pair of homologous chromosomes or sister chromatids fails to separate properly.

Karyotype

A photographic inventory of an individual's chromosomes, ordered by size and shape, used to detect chromosomal abnormalities.

Trisomy 21

A human genetic condition characterized by having three copies of chromosome 21 instead of two, resulting in Down syndrome.

Law of Segregation

Mendel's rule stating that allele pairs separate from each other during gamete formation, so each sperm or egg carries only one allele for each gene.

Law of Independent Assortment

Mendel's principle stating that alleles of a pair segregate independently of other allele pairs during gamete formation.

Testcross

A mating between an individual of unknown genotype and a homozygous recessive individual to determine the unknown genotype.

Incomplete Dominance

A pattern of inheritance in which the phenotype of F1​ hybrids is intermediate between the phenotypes of two parent varieties.

Codominance

An An inheritance pattern in which two different alleles for a gene are both fully expressed in heterozygous individuals.

Pleiotropy

A property where a single gene influences multiple phenotypic characters.

Polygenic Inheritance

An additive effect of two or more genes on a single phenotypic character, such as human height or skin color.

Linked Genes

Genes located close together on the same chromosome that tend to be inherited together.

Transforming Principle

The chemical material discovered by Frederick Griffith that transferred pathogenic traits from heat-killed virulent bacteria to living harmless bacteria.

Semiconservative Model

The model of DNA replication in which each newly formed double-stranded DNA molecule consists of one original parental strand and one newly synthesized strand.

DNA Polymerase

An enzyme that catalyzes the synthesis of new DNA strands by adding complementary nucleotides exclusively to the free $3'$ end of a growing strand.

DNA Ligase

An enzyme that covalently links Okazaki fragments together into a continuous DNA strand during replication.

Codon

A nonoverlapping three-base sequence (triplet codon) in mRNA that specifies a particular amino acid or stop signal during translation.

promoter (TATA box)

A specific nucleotide sequence in DNA that functions as a binding site for RNA polymerase and determines where transcription begins.

RNA Splicing

The post-transcriptional process in eukaryotic nuclei where noncoding introns are removed and coding exons are joined together.

Cap (5’ end it is a modified Guanine) and 3’ tail added to the ends of the MRNA

Anticodon

A specific triplet of bases at one end of a tRNA molecule that is complementary to a specific codon triplet on mRNA.

Transformation

The uptake of foreign DNA fragments from the surrounding environment by a bacterial cell.