TEAS Biology Flashcard Study Material

List the Components of the Biological Hierarchy of life

Atoms > Molecules > Organelles> Cells > Tissues > Organs > Organ Systems > Organism

Prokaryotes

Eukaryotes

Cell membrane (plasma membrane)

This defines the cell by acting as a barrier. It keeps cytoplasm in, and substances located outside the cell out. It also determines what is allowed to enter and exit the cell, " Gatekeeper"

Golgi apparatus

Helps process and package proteins and lipids, specifically proteins to be exported out of the cell.

Cytoplasm

Supports and suspends structures inside the cell membrane; transfer materials required for cellular processes

Lysosome

Aids in digestion of macromolecules, the recycling of old cell materials; may help destroy invading viruses and bacteria.

Mitochondrion

"Powerhouse of the cell": Generates chemical energy in the form of ATP molecules

Rough Endoplasmic Reticulum

Contains ribosomes; synthesizes and processes proteins in the cell

Nucleus

"Control center of the Cell": a small structure that contains the chromosomes and regulates the DNA of a cell

Nucleous

Area inside the nucleus which assembles RNA+ proteins into Ribsosomes

Smooth Endoplasmic Reticulum

> Does not contain ribosomes; synthesizes and processes lipids in the cell

> Inactivates toxins and harmful metabolic products

Vacuoles

Sacs used for storage, digestion, and waste removal.

-Plant: Has one large vacuole

-Animal: Has small, sometimes numerous vacuoles.

Ribsosomes

"Site of protein synthesis" (many are found on the surface of the rough endoplasmic reticulum although some can be free floating in the cytoplasm.

Chromatin

This consists of DNA and proteins that make up chromosomes

Nuclear Envelope

This encloses the structure of the nucleus. It consists of inner and outer membranes of lipids.

Nuclear Pores

They are involved in the exchange of materials between the nucleus and the cytoplasm.

Vesicle

This is a small organelle within a cell. It has a membrane and preforms varying functions including moving materials within a cell.

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Cytosol

This is the liquid material in the cell. It is mostly water, but also contains some floating molecules.

Microtubules

These are part of the cytoskeleton and help support the cell. They are made of protein.

Mitosis

Cell Division that results in 2 genetically identical diploid daughter cells, with each having the same # and kind of chromosomes (46): 23 from mom + 23 from dad

Mitosis- Interphase

DNA replicates

Mitosis-Prophase

Chromosomes become visible as they condense and thicken

Mitosis: Metaphase

Chromosomes align in the middle of the cell's center, forming a single row.

Mitosis: Anaphase

Sister chromatids are split at the centromere and pulled apart. (A= Anaphase)

Mitosis-Telophase

> Chromosomes uncoil

> A nuclear membrane forms around each set of chromosomes

>A nucleolus forms in each new nucleus

> The mitotic spindle breaks down

> Cytokinesis begins

Mitosis- Cytokinesis

Splits the cytoplasm of the cell

(* Two genetically Identical Daughter Cells)

Meiosis

Cell Division that results in 4 Haploid Gametes/ Cells, with half the number of chromosomes of the parent cell (23)

> undergoes two stages of meiosis

Meiosis-Interphase

DNA replicates

Meiosis- Prophase I

homologous chromosomes pair and cross over

Meiosis- Metaphase I

Chromosomes align in the middle of the cell's center maintaining their homologous pairing

Meiosis- Anaphase I

Chromosomes are pulled apart towards separate ends of a pole.

Meiosis-Telophase I

Nuclear membrane forms and cell separates into two, Cytokinesis I begins.

Meiosis: Cytokinesis I

Splits the cytoplasm of the cell

Meiosis: Prophase II

Chromosome condensation in both cells

Meiosis: Metaphase II

Chromosomes align in the middle of the cell's center forming a single layer

Meiosis: Anaphase II

Sister Chromatids are separated and drawn to opposite ends of the spindle fibers

Meiosis: Telophase

> Nuclear membrane forms as two cells separate via Cytokinesis II resulting in

= 4 Genetically Distinct Haploid cells (23 chromosomes)

Deoxyribonucleic acid (DNA)

is a macromolecule that contains genes that are coded instructions for a cell to produce proteins

Structures of DNA

" Twisted Ladder or Double Helix"

> The sides: a phosphate and a deoxyribose sugar

> The rungs of the ladder are composed of four nucleotide bases

The four nucleotides of DNA

Adenine, Thymine, Cytosine, Guanine

Pairing of DNA Bases

Apple in Tree: Adenine= Thymine

Car in Garage: Cytosine = Guanine

Nucleotide are composed of

5 carbon sugar, phosphate group, nitrogenous base

Genes

segments of DNA that control a trait

Chromosomes

consist of coiled DNA wrapped around histone proteins

Structural Genes

Trait expression

Regulatory Genes

"non-coding regions"

> genes can be activated and deactivated through various mechanisms (gene regulation)

Ribonucleic Acid (RNA)

Principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins

> Present inside and outside the nucleus

Structure of RNA

single chain of ribose sugar (pentose-1 extra oxygen) + phosphate group

4 nucleotides of RNA

Adenine, Uracil, Guanine, Cytosine

Pairings of RNA bases

Apple Under the tree: Adenine = Uracil

Car in the Garage: Cytosine = Guanine

Messenger RNA (mRNA)

carries a copy of a strand of DNA and transports it from the nucleus to the cytoplasm

Ribosomal RNA (rRNA)

Significant structural component for ribosomes themselves

Transfer RNA (tRNA)

type of RNA molecule that transfers amino acids to growing polypeptide chain

>anticodon (compliment to codon)

Transcription

"to copy" or "to rewrite"

> The process in which RNA polymerase copies DNA into RNA

Translation

is the process where ribosomes use tRNA to put together the needed protein

Codon

are groups of three nucleotides on the messenger mRNA, " three rungs on a ladder''

Transcription and translation process

1.DNA in the nucleus serves as a template for mRNA

>( RNA polymerase)

2. mRNA is processed before leaving the nucleus

3. mRNA moves into the cytoplasm and becomes associated with ribosomes

4. tRNAs with anti-codons carry amino acids to mRNA

5. anticodon-codon complementary base pairing occurs

6. polypeptide synthesis takes place one amino acid at a time in ribosome by rRNA

Start Codon

AUG (methionine)

Stop Codons

UAA, UGA, UAG also known as ocher, opal, and amber

Peptide Bond

the link between amino acids in a protein

Genome

all of an organism's genetic material

Inheritance

transmission of characteristics to offspring

Law of Segregation

States that an organism receives half of its total number of alleles from each parent

Law of Dominance

States that when two different alleles are present in a pair, the dominant one is expressed

Law of Independent Assortment

States that traits are passed on randomly and are not influenced by other traits, the exception being linked traits

Allele

A variant of a gene (aka a trait), often recognized by letters

(F= fur, f= no fur)

Genotype

refers to the combination of two alleles present in the genetic makeup of an individual

Homozygous genotype

"Homo" means same

> FF= Homozygous Dominant

> ff= Homozygous Recessive

Heterozygous genotype

"Hetero" means different

> Ff= heterozygous dominant

Phenotype

Physical appearance of a trait formed by genetics and the environment

Genetic crosses

are the possible combinations of alleles and can be represented using Punnett squares.

Punnett Square

A square diagram used to determine the various genotype combinations that may be passed from parent to offspring and their likelihood of occurring

Monohybrid Cross

refers to a cross involving only one trait

> 3:1 ratio of dominant to recessive

Dihybrid Cross

refers to a cross involving more than one trait (two traits)

> ratio of 9:3:3:1 when traits are not linked

Co-Dominance

refers to the expression of both alleles so that both traits are fully expressed and showing distinct traits together

(Cows and blood types)

Incomplete Dominance

Heterozygous phenotype that is a blend of the two homozygous phenotypes

(Snapdragons: RR=red pigment, rr= no pigment. (Rr) Pink pigment occurs because 1 gene is for red+ one is for no pigment

> 1:2:1

polygenetic inheritance

refers to traits that are influence by more than one gene

EX: skin

multiple alleles

refers to a gene with more than two possible alleles

EX: blood

Blood typing: 3 alleles: A, B, O: only have two

Non-Mendelian Inheritance

inheritance of traits that do not follow Mendelian patterns of inheritance (factors other than Dom -recessive relationships at play)

Monomer

A simple compound whose molecules can join together to form polymers

Polymers

large compound formed from combinations of many monomers

Macromolecule

A very large organic molecule composed of many smaller molecules

Carbohydrates

Primary source of energy and are responsible for providing energy as they can easily be converted to glucose

> take on the form CH20

Simple sugars

are grouped into monosaccharides (glucose, fructose, and galactose)

Lipids

Composed of 3 fatty acids + one glycerol

> hydrophobic

> do not have a true monomer because they do not have repeating units

> cell membrane: phospholipids

>Numerous C-H bonds

Proteins

Polymer unit made of amino acids

> composed of a central carbon, an anime group, carboxylic acid and a side group

> Enzymes: are biological catalysts: speed up chemical reactions: Endergonic: release energy, Exergonic: require energy

Nucleic Acids:

are polymers that are made up of monomers called nucleotides that contain CHNOP

4 macromolecules produced by Anabolic reactions

Carbohydrates, Lipids, proteins, Nucleic acids (DNA or RNA)

Anabolic Reaction

the synthesis of larger and more complex molecules (macromolecules) from smaller ones; require energy

4 Building Blocks involved in Catabolic Reactions

monosaccharides (glucose)

amino acids

fatty acids (glycerol)

nucleotides.

5 components of the cycle of infection

reservoir host, portal of exit, method of transmission, route of entrance, susceptible host

microbes/ microorganism

organisms that cannot be seen with the naked eye and may be classified as bacteria, viruses, fungi, and protozoa

Parasites

Microbes that are not free-living and must find a host from which to gain nutrients

Host

An organism on which a parasite lives.

Pathogen

an infectious agent capable of causing disease

Virulence

the severity or harmful potential of a pathogen

1. Reservoir (host)

an animal, insect, or human whose body is susceptible to growth of a pathogen

2. Portal of Exit

a way for the infectious agent to escape from the reservoir in which it has been growing+ infect another

(Ex: via mouth nose, blood, urine, vaginal fluid, feces, eyes)