Biology final sg questions

How is energy released from an ATP molecule, and what does it become after the energy is used

Energy is released when ATP loses its third phosphate bond and becomes ADP.

Explain why cellular respiration is considered a biochemical pathway

Cellular respiration is considered a biochemical pathway because it uses multiple chemical reactions to break down glucose and make ATP.

Compare where the beginning and end of cellular respiration take place within a eukaryotic cell

Glycolysis happens in the cytoplasm, while the Krebs cycle and electron transport chain happen in the mitochondria.

Why do your muscles feel sore after extreme exercise in terms of fermentation

Your muscles switch to lactic acid fermentation when oxygen is low, causing lactic acid buildup.

Describe the relationship between the products of photosynthesis and the reactants of cellular respiration

The glucose and oxygen made in photosynthesis are used in cellular respiration.

What is the specific role of oxygen in the Electron Transport Chain

Oxygen is the final electron acceptor and helps form water.

In the Krebs Cycle, what happens to the carbon atoms that were originally part of the glucose molecule

The carbon atoms are released as carbon dioxide.

Why is it beneficial for a plant cell to have both chloroplasts and mitochondria

Chloroplasts make glucose and mitochondria break glucose down for energy.

Contrast the energy output (ATP) of aerobic respiration versus anaerobic fermentation

Aerobic respiration makes about 36–38 ATP while fermentation makes only 2 ATP.

How does a chemoautotroph differ from a photoautotroph in how it obtains energy

A chemoautotroph gets energy from chemicals while a photoautotroph gets energy from sunlight.

Why did Gregor Mendel remove the anthers (male parts) of certain pea plants during his experiments

Gregor Mendel removed the anthers to prevent self-pollination and control breeding.

Define the Law of Segregation in your own words

The Law of Segregation states that allele pairs separate during gamete formation.

Explain the Law of Independent Assortment and how it contributes to genetic variety

The Law of Independent Assortment increases genetic variation because genes for different traits are inherited independently.

What is the difference between an organism’s genotype and its phenotype

Genotype is an organism’s genetic makeup, while phenotype is its physical traits.

If a trait appears in every generation of a family’s pedigree, is it likely dominant or recessive

A trait that appears in every generation is most likely dominant because it does not skip generations.

Describe a scenario involving codominance in animal fur or flower color

A red flower and a white flower could produce offspring with both red and white petals showing equally.

How does a monohybrid cross differ from a dihybrid cross

A monohybrid cross studies one trait, while a dihybrid cross studies two traits.

Explain why a male is more likely to express a sex-linked (X-linked) recessive trait than a female

Males only have one X chromosome, so one recessive allele will be expressed.

What does a carrier represent in a genetic pedigree

A carrier has one recessive allele for a trait but does not show the trait.

How can environmental factors such as altitude or temperature affect the expression of a gene

Environmental factors can turn genes on or off and affect how traits are expressed.

What are the three components of a single nucleotide

A nucleotide contains a sugar, phosphate group, and nitrogen base.

Explain Erwin Chargaff’s rules regarding DNA base pairing

Adenine pairs with thymine and cytosine pairs with guanine.

Contrast the structural differences between DNA and RNA

DNA is double-stranded and contains deoxyribose, while RNA is single-stranded and contains ribose.

Describe the process of DNA replication and why it is called semi-conservative

DNA replication copies DNA by using one old strand and one new strand in each molecule.

What is the primary goal of the transcription process

The goal of transcription is to make mRNA from DNA.

Where in the cell does translation occur, and what organelle is responsible for it

Translation occurs at ribosomes in the cytoplasm.

Define the role of tRNA during the assembly of a protein

tRNA brings amino acids to the ribosome during protein synthesis.

What is a codon, and how many nucleotides make up one

A codon is a three-nucleotide sequence that codes for an amino acid.

Explain how a mutation in a DNA sequence might result in a non-functional protein

A mutation can change amino acids and cause the protein to fold incorrectly.

What is the difference between a purine and a pyrimidine

Purines have two rings while pyrimidines have one ring.

What was the main objective of the Miller–Urey experiment

It tested whether organic molecules could form under early Earth conditions.

Describe the Endosymbiont Theory regarding the origin of mitochondria

The theory states that mitochondria were once free-living bacteria.

How does relative dating help scientists determine the age of fossils

Relative dating compares rock layers to determine which fossils are older or younger.

Explain the Law of Superposition in the context of a hillside with many rock layers

Lower rock layers are older than the layers above them.

What was the significance of the Cambrian Explosion in Earth’s history

Many new life forms appeared rapidly during this time.

How did the breakup of Pangaea affect the evolution of separated populations

It separated populations, causing species to evolve differently.

What did Louis Pasteur’s S-shaped flask experiment prove regarding biogenesis

It proved that living things come from other living things.

Why is the presence of circular DNA in chloroplasts considered evidence for endosymbiosis

Circular DNA suggests chloroplasts were once independent bacteria.

Describe the atmospheric conditions of early Earth compared to Earth today

Early Earth had little oxygen and more volcanic gases compared to today.

How can a mass extinction event actually lead to an increase in biodiversity over time

Mass extinctions open niches that allow new species to evolve.

Why do scientists use Latin binomial nomenclature instead of common names

Scientists use Latin names because they are universal and avoid confusion.

List the levels of biological hierarchy from Kingdom down to Species

Kingdom, Phylum, Class, Order, Family, Genus, Species.

What is a cladogram, and what does it represent

A cladogram is a diagram that shows evolutionary relationships.

Explain the difference between an ancestral character and a derived character

An ancestral character is shared by older ancestors, while a derived character is a newer trait.

Define taxonomy in the context of evolutionary history

Taxonomy is the classification of organisms based on shared traits and ancestry.

What is homeostasis

Homeostasis is maintaining stable internal conditions.

Give an example of a negative feedback loop in the human body

Sweating when body temperature rises is a negative feedback loop.

How does a cell membrane contribute to the homeostasis of a single cell

The cell membrane controls what enters and leaves the cell.

What happens to an organism if it is unable to maintain homeostasis

The organism may become sick or die.

Why is structure often related to function in biological systems

The shape of a biological structure helps it perform its specific job.