From Molecules to Organisms
What is the role of DNA in protein synthesis?
DNA contains the instructions for building proteins. It is transcribed into RNA, which is then translated into a specific sequence of amino acids to form proteins.
What are biotic factors in an ecosystem?
Biotic factors are the living parts of an ecosystem, such as plants, animals, bacteria, fungi, and humans.
How is genetic information passed to offspring?
Genetic information is passed from parents to offspring through DNA in chromosomes during sexual reproduction (meiosis and fertilization).
What evidence supports common ancestry?
Fossils, DNA similarities, embryology, and anatomical structures all provide evidence for common ancestry among organisms.
Describe the function of the digestive system in animals.
The digestive system breaks down food into smaller molecules like glucose, amino acids, and fatty acids that are absorbed into the bloodstream and used by the body for energy and growth.
How do abiotic factors influence biodiversity?
Abiotic factors like temperature, sunlight, pH, and moisture levels influence which species can survive, thus affecting biodiversity.
What is a mutation, and how can it affect traits?
A mutation is a change in the DNA sequence. It can lead to changes in traits by altering the proteins produced, which may be beneficial, harmful, or neutral.
Describe natural selection in your own words.
Natural selection means individuals with traits better suited to their environment are more likely to survive and reproduce, passing those traits on.
What is homeostasis? Provide an example.
Homeostasis is the maintenance of a stable internal environment.
➤ Example: Sweating to cool down when body temperature rises.
Explain energy transfer between trophic levels.
Only about 10% of energy is transferred from one trophic level to the next; the rest is lost as heat. Producers → Primary Consumers → Secondary Consumers → Tertiary Consumers.
Explain how to use a Punnett square.
A Punnett square is used to predict the probability of offspring genotypes and phenotypes based on the alleles from each parent.
What are key features of viruses?
Viruses are non-living, made of genetic material (DNA or RNA) inside a protein coat, and they must infect a host to reproduce.
Explain why the cell cycle is important.
The cell cycle allows for cell growth, DNA replication, and cell division, which are essential for development, repair, and replacement of cells.
Describe the carbon cycle's main processes.
The carbon cycle includes processes such as photosynthesis, respiration, decomposition, and combustion that move carbon through the atmosphere, organisms, and Earth.
What factors influence trait variation in populations?
Trait variation can be influenced by genetic differences (alleles), mutations, and environmental factors such as nutrition or climate.
Explain how genetic drift can lead to evolution.
Natural selection means individuals with traits better suited to their environment are more likely to survive and reproduce, passing those traits on.
What are the main products of photosynthesis?
The main products of photosynthesis are glucose (C₆H₁₂O₆) and oxygen (O₂).
What is a human activity that affects biodiversity?
Deforestation, pollution, overfishing, and urban development are human activities that reduce biodiversity.
How does environmental change affect genetic variation?
Environmental changes can create new selective pressures, increasing or decreasing certain traits in a population. They may increase genetic variation if they lead to new mutations or migrations.
How do new species emerge according to evolution? make an answer key
Fossils, DNA similarities, embryology, and anatomical structures all provide evidence for common ancestry among organisms.