DNA and Proteins
This is the shape of the DNA molecule, characterized by its twisted ladder structure.
What is a double helix?
This theory states that all living things are composed of cells, and all cells arise from pre-existing cells.
What is the cell theory?
This term refers to the range of environmental conditions within which a particular species can survive.
What is tolerance limits?
Life on Earth is estimated to have existed for this many billion years.
What is approximately 3.5 billion years?
This is a prediction that can be tested through an experiment.
What is a hypothesis?
These are the four nucleotides that make up DNA.
What are adenine (A), thymine (T), cytosine (C), and guanine (G)?
These are the two major types of cells, distinguished by the presence or absence of a defined nucleus.
What are prokaryotic and eukaryotic cells?
This is the process by which living organisms regulate their internal environment to maintain a stable, constant condition.
What is homeostasis?
These catalytic RNA molecules provide evidence for the RNA world hypothesis, which proposes that RNA may have acted as both genetic material and a catalyst in early life.
What are ribozymes?
This is the variable that is deliberately changed during an experiment.
What is the independent variable?
This process is how DNA is copied before cell division.
What is DNA replication?
This organelle is the site of the later stages of aerobic respiration.
What is the mitochondrion?
Excluding the stimulus and response, these are the three primary components of a homeostatic pathway in the body.
What are the receptor, control centre and effector?
This evolutionary theory suggests how eukaryotic cells might have evolved from prokaryotic cells.
What is the endosymbiotic theory?
This is the group in an experiment that does not receive the treatment being investigated and is used as a baseline for comparison.
What is the control group?
These are the base-pairing rules that RNA follows.
What is adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G)?
This model describes the cell membrane as a fluid structure with a 'mosaic' of various proteins embedded in or attached to a bilayer of phospholipids.
What is the fluid mosaic model?
This part of the nervous system consists of the brain and spinal cord.
What is the central nervous system?
This field of study compares the genomes of different species to provide evidence for evolution and establish evolutionary relationships.
What is comparative genomics?
This type of error causes measurements to be consistently higher or lower than the true value due to a flaw in the equipment or experimental method.
What is systematic error?
This type of RNA carries the genetic information from DNA to the ribosomes, where proteins are synthesized.
What is messenger RNA (mRNA)?
This is the balanced chemical equation for photosynthesis.
What is 6CO₂ + 6H₂O (in the Presence of Light + Chlorophyll) → C₆H₁₂O₆ + 6O₂?
This type of neuron transmits impulses from sensory receptors to the central nervous system.
What is a sensory neuron?
This concept uses the rate of mutations in DNA to estimate the time since two species diverged from a common ancestor.
What is the molecular clock?
Increasing the number of participants or trials in an experiment can reduce the effect of this type of error.
What is random error?
These are the three types of RNA involved in the process of protein synthesis.
What are mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA)?
These are the two types of anaerobic respiration used by organisms to produce ATP.
What are alcoholic fermentation and lactic acid fermentation?
This is the type of rapid, automatic response to a stimulus.
What is a reflex action?
This refers to the complete set of genes (or alleles) present in all individuals within a population.
What is the gene pool?
A student investigates how light intensity affects the rate of photosynthesis in pondweed. They measure the number of oxygen bubbles produced per minute at different distances from a light source. The number of oxygen bubbles produced per minute is this type of variable.
What is the dependent variable?
This term describes the segments of DNA in eukaryotes that do not code for proteins and are removed during RNA processing.
What are introns?
This is the process by which prokaryotic cells reproduce, resulting in two genetically identical cells.
What is binary fission?
These two hormones have opposite effects on blood glucose levels.
What are insulin and glucagon?
This type of speciation occurs when biological populations are geographically isolated from each other.
What is allopatric speciation?
A student investigates how pH affects the rate at which amylase breaks down starch. They test different pH levels but ensure that each experiment uses the same concentration and volume of amylase, the same concentration and volume of starch, and the same temperature. These are examples of this type of variable.
What are controlled variables?
This level of protein structure is characterized by the unique three-dimensional shape resulting from interactions between R-groups of amino acids.
What is the tertiary structure?
These are the four phases of mitosis in eukaryotic cells.
What are prophase, metaphase, anaphase, and telophase?
This hormone, secreted by the pituitary gland, acts on the kidneys to regulate the concentration of urine.
What is antidiuretic hormone (ADH)?
These are reproductive barriers that prevent mating or fertilisation from occurring between individuals of different species.
What are prezygotic barriers?
When repeated measurements produce results that are very close together, with little scatter between them, the data demonstrates this quality.
What is precision?
This model describes how enzymes change shape to bind to their substrates more effectively.
What is the induced fit model?
This is the term for the exchange of genetic material between homologous chromosomes during meiosis, contributing to genetic diversity.
What is crossing over?
This type of feedback mechanism results in the inhibition of an initial stimulus to return the body to homeostasis.
What is negative feedback?
This is the ultimate source of genetic variation, introducing new alleles into a population.
What are mutations?
This describes how close a measured result is to the true or accepted value.
What is accuracy?
This recent gene-editing technology allows for precise modifications in the DNA sequence of organisms.
What is CRISPR-Cas9?
This is the term for the process of growing cells under controlled conditions, often used for research, medical treatments, or biotechnology.
What is cell culture?
This hormone is released in response to TSH and increases metabolic rate and heat production, helping regulate body temperature.
What is thyroxine?
In a population of bacteria exposed to antibiotics, individuals with an allele providing resistance are more likely to survive and reproduce, increasing the frequency of this allele over generations. This example illustrates this evolutionary process.
What is natural selection?
An experiment produces consistent results when repeated, but the method used does not accurately measure what it was intended to investigate. These are two important aspects of evaluating experimental results.
What are reliability and validity?