Biology Flashcards
(18 cards)
What are the differences between prokaryotic and eukaryotic cells?
Prokaryotic cells (bacteria) have no nucleus and DNA is in a single loop or plasmids, while eukaryotic cells (animal & plant) have a nucleus containing DNA.
What is the main difference between mitosis and meiosis?
Mitosis produces two identical diploid cells for growth/repair, while meiosis produces four genetically different haploid cells for reproduction.
How does temperature affect enzyme activity?
Too low = slow reaction. Optimum = fastest rate. Too high = enzyme denatures and loses function.
Define osmosis
The movement of water molecules across a partially permeable membrane from a high to low water concentration.
What is the word equation for photosynthesis?
Carbon dioxide + water → glucose + oxygen (in the presence of light and chlorophyll).
What are enzymes?
Biological catalysts that speed up chemical reactions without being used up.
What are the three types of biological molecules and their enzyme breakdown products?
Carbohydrates → Glucose (by amylase).
Proteins → Amino acids (by protease).
Lipids → Fatty acids & glycerol (by lipase).
What happens in mitosis?
A parent cell divides into two identical diploid daughter cells for growth and repair.
What is the role of stem cells?
They can divide and differentiate into different types of cells.
What is the function of the cerebrum?
Controls memory, thinking, and voluntary actions.
What is the difference between genotype and phenotype?
Genotype = The alleles an organism has (e.g Bb)
Phenotype = The physical characteristic expressed (e.g brown eyes).
What is the structure of DNA?
A double helix made of nucleotides, with bases A, T, C, and G (A pairs with T, C pairs with G)
What is meiosis?
A type of cell division that produces four genetically different haploid gametes for sexual reproduction.
What are the steps of natural selection?
- Variation exists in a population.
- Individuals with advantageous traits survive and reproduce
- These traits are passed on to offspring.
- Over time, the population adapts to the environment.
What is selective breeding?
Humans choosing organisms with desirable traits to breed, increasing those traits in the population.
What is the difference between communicable and non-communicable diseases?
Communicable: Caused by pathogens, can spread (e.g flu, HIV).
Non-communicable: Not caused by pathogens, can’t spread (e.g cancer, diabetes).
What is the function of white blood cells?
They fight infections by engulfing pathogens, producing antibodies, and releasing antitoxins.
