Honors Biology Final Review Flashcards

Comprenhensive biology flashcards covering cellular respiration, photosynthesis, mitosis, meiosis, genetics, and DNA replication based on the honors biology review guide.

What is the main function of cellular respiration?

It is an exergonic (energy-releasing) process that transfers energy from glucose to form $ATP$.

What gas is required as a reactant in cellular respiration?

Oxygen ($O_2$)

Besides ATP, what are the other products generated by the breakdown of food molecules during cellular respiration?

Carbon Dioxide ($CO_2$), Water ($H_2O$), and heat

What is the energy currency in cells?

$$ATP$$

How do cells extract energy from fuel molecules during respiration?

Through the transfer of electrons in chemical reactions.

Initially, where are electrons removed from fuel molecules transferred?

To $NAD^+$ (which becomes reduced to $NADH$).

As electrons ‘fall’ from carrier to carrier in the electron transport chain, what is released?

Energy

How is most of the ATP manufactured during cellular respiration?

Through oxidative phosphorylation.

What is the maximum number of ATP molecules produced for every glucose molecule oxidized?

$$32\,ATP$$

What two processes specifically produce ATP in cellular respiration?

Substrate-level phosphorylation and oxidative phosphorylation.

What are the two reactants needed for cellular respiration?

Glucose and oxygen ($O_2$).

What are the three main products of cellular respiration?

Carbon Dioxide ($CO_2$), Water ($H_2O$), and Heat.

What mnemonic is used to remember the transfer of electrons?

LEO the lion goes GER

Define oxidation in the context of cellular respiration.

The removal (loss) of electrons from fuel molecules.

Define reduction in the context of cellular respiration.

The transfer (gain) of electrons to a molecule like $NAD^+$.

What is aerobic metabolism?

Metabolism that requires oxygen ($O_2$).

What is anaerobic metabolism?

Metabolism that does not require oxygen ($O_2$).

What is the name of the 3-carbon compound produced by breaking down glucose in glycolysis?

Pyruvate

Where is the energy locked in the original glucose molecule eventually released?

The electron transport chain (ETC) and oxidative phosphorylation.

What and where is the electron transport chain (ETC)?

A network of electron-carrying proteins located in the inner membrane of the mitochondrion.

In the ETC, what do electrons combine with to form water?

Protons ($H^+$) and oxygen ($O_2$).

What force is defined as a store of potential energy used to form ATP?

Proton motive force

What is Stage 1 of cellular respiration?

Glycolysis

Where does glycolysis occur?

In the cytosol.

What takes place during Stage 2 of cellular respiration?

Pyruvate oxidation and the citric acid cycle.

Where do Stage 2 reactions take place?

In the mitochondria.

What organic molecules shuttle electrons to the electron transport chains in Stage 3?

$NADH$ and $FADH_2$

In Stage 3 of respiration, what does oxygen become after it is reduced?

Water ($H_2O$).

What is the primary equation for Photosynthesis?

$$6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$$

What is the purpose of photosynthesis?

To transform light energy into chemical energy stored in the bonds of sugar.

What are the three reactants for photosynthesis?

Light Energy, Carbon Dioxide ($CO_2$), and Water ($H_2O$).

What are the two major products of photosynthesis?

Glucose and Oxygen Gas ($O_2$).

Define a photoautotroph.

Organisms (like plants, algae, and some bacteria) that produce food consumed by heterotrophs using light as an energy source.

What is an autotroph?

An organism that makes its own food (not necessarily through sunlight).

Where is chlorophyll specifically found in a plant cell?

Inside chloroplasts, specifically in the thylakoid membrane.

What color pigment does chlorophyll give to leaves?

Green

What are photons?

Fixed quantities of light energy; the shorter the wavelength, the greater the energy.

Where do the light reactions of photosynthesis take place?

In the thylakoid membranes of chloroplasts.

What chemical energy forms are produced by light reactions?

$ATP$ and $NADPH$

What is released as a byproduct during light reactions?

Oxygen ($O_2$)

Where do dark reactions (Calvin cycle) occur?

In the stroma of the chloroplasts.

Do dark reactions require light directly?

No, they use the $ATP$ and $NADPH$ produced in the light reactions.

What is the full range of electromagnetic energy called?

Electromagnetic Spectrum

Order electromagnetic energy from most powerful to weakest (stronger to weaker).

Gamma rays to radio waves.

Which types of electromagnetic rays are the most powerful and dangerous?

Gamma Rays

Which types of electromagnetic rays are the weakest and least dangerous?

Radio Waves

What color is reflected by Chlorophyll A and Chlorophyll B?

Green

In which parts of the electromagnetic spectrum does chlorophyll absorb light most efficiently?

Blue-violet and red parts.

What is the purpose of the electron transport chains in light reactions?

To move $H^+$ ions across the membrane to create energy for $ATP$ synthase.

What enzyme uses the power of $H^+$ ions to change $ADP$ to $ATP$?

$ATP$ synthase

Where does the carbon used by plants in photosynthesis originate?

Carbon dioxide ($CO_2$) in the atmosphere.

What is G3P (Glyceraldehyde 3-phosphate)?

A 3-carbon sugar that is the product of the Calvin cycle and a starting point for other carbohydrates.

What does the phrase 'Like begets like' mean?

Offspring inherit characteristics from parents, so a particular species produces offspring of the same species.

How do prokaryotic cells reproduce?

Asexually through binary fission.

In animal cells, how does cytokinesis occur?

The cell constricts, forming a cleavage furrow.

In plant cells, how does cytokinesis occur?

A membranous cell plate forms and then splits the cell in two.

List the phases of mitosis in the correct order.

Interphase, prophase, metaphase, anaphase, telophase, and cytokinesis.

What occurs during the Interphase stage of the cell cycle?

Cell growth, organelle synthesis, DNA synthesis, and chromatin condensing.

What characterizes Prophase in mitosis?

The nuclear envelope dissolves, microtubules extend, and chromosomes condense.

What occurs during Metaphase?

Chromosomes align along the metaplate and remain joined at the centromere.

What are sister chromatids?

Two identical halves of a duplicated chromosome joined together by a centromere.

What happens during Anaphase?

Sister chromatids separate and are pulled in opposite directions as the cell elongates.

What occurs during Telophase and Cytokinesis?

Nuclear envelopes form, daughter cells form, and microtubules go away.

Define gametes.

Mature haploid germ cells (eggs and sperm) that unite during sexual reproduction to form a zygote.

Define somatic cells.

Body cells (autosomes) that are genetically identical to the parent.

How many chromosomes are in human gametes?

$$23$$

How many chromosomes are in human somatic cells?

$46$ chromosomes ($23$ pairs).

How many times does a cell divide in meiosis?

Twice, forming four daughter cells.

How many daughter cells are produced in mitosis?

Two

How many daughter cells are produced in meiosis?

Four

What is the genetic nature of daughter cells in mitosis?

Genetically identical diploid somatic cells.

What is the genetic nature of daughter cells in meiosis?

Genetically unique haploid gametes.

Define binary fission.

Asexual reproduction where a single organism divides into two identical daughter cells.

What does 'haploid' refer to?

Cells containing a single set of chromosomes.

What does 'diploid' refer to?

Cells containing two complete sets of chromosomes, one from each parent.

In which phase of meiosis does crossing over occur?

Prophase I

What is crossing over?

The exchange of corresponding segments between non-sister chromatids of homologous chromosomes.

What is synapsis?

The pairing of homologous chromosomes during meiosis.

Define a tetrad.

A group of four chromatids formed by the pairing of two homologous chromosomes during meiosis.

What is a karyotype?

A visual arrangement of an individual's chromosomes by size, shape, and banding pattern.

What is a homozygous organism?

An organism that has two identical alleles for a gene (e.g., $TT$ or $tt$).

What is a heterozygous organism?

An organism that has two different alleles for a gene (e.g., $Tt$).

What is a monohybrid cross?

A genetic cross involving one trait or one gene.

State the Law of Segregation.

Sperm or eggs carry only one allele for each character because allele pairs separate during gamete production.

State the Law of Independent Assortment.

Alleles of a pair segregate independently of other allele pairs during gamete formation.

What are alleles?

Alternative versions of genes that account for variations in inherited traits.

What is a testcross?

Mating between an individual of unknown genotype and a homozygous recessive individual.

What can family pedigrees help determine?

Individual genotypes.

What is cancer in terms of the cell cycle?

When the cell cycle is not controlled due to damaged DNA.

What are the chemical monomers that make up DNA and RNA?

Nucleotides

What are the three components of a nucleotide?

A nitrogenous base, a five-carbon sugar, and a phosphate group.

What sugar is found in DNA?

Deoxyribose

What sugar is found in RNA?

Ribose

Which nitrogenous base is found in RNA but not DNA?

Uracil ($U$)

Which nitrogenous base is found in DNA but not RNA?

Thymine ($T$)

What are the two nitrogenous bases classified as Purines?

Guanine ($G$) and Adenine ($A$).

What is the mnemonic for remembering Purines?

Aunt Ginny is PURe

What are the nitrogenous bases classified as Pyrimidines in DNA?

Cytosine ($C$) and Thymine ($T$).

Define transcription.

The synthesis of RNA under the direction of DNA.

Define translation.

The synthesis of proteins under the direction of RNA.