Science: Life Science Practice Test Flashcards

Which of the following correctly describes the process of osmosis?

Answer: Movement of water from high to low solute concentration across a semipermeable membrane

Osmosis is the passive movement of water across a semipermeable membrane from areas of lower solute concentration to higher solute concentration.

If both parents are heterozygous (Tt) for a trait where T (tall) is dominant, what is the probability their offspring will be tall?

Answer: 75%

A Tt × Tt cross produces TT, Tt, Tt, tt in a 1:2:1 ratio; three out of four genotypes express the tall phenotype, giving 75% probability.

Which of the following describes a food web rather than a food chain?

Answer: A diagram showing multiple interconnected feeding relationships among species

A food web shows the complex network of interconnected feeding relationships, while a food chain shows only one linear pathway.

What is the function of the nephron in the kidney?

Answer: Filter blood and form urine

Nephrons are the functional units of the kidney that filter blood, reabsorb needed substances, and produce urine from waste products.

Which type of RNA reads the mRNA codon and brings the correct amino acid during translation?

Answer: tRNA

Transfer RNA (tRNA) has an anticodon that pairs with mRNA codons and carries the corresponding amino acid to the ribosome.

A species of bird with a longer beak is better able to reach insects under tree bark. Over many generations, the average beak length in the population increases. This is an example of:

Answer: Natural selection

Natural selection favors the longer-beaked birds because they survive and reproduce more successfully, shifting the population's average beak length.

Which cellular process requires oxygen as a reactant?

Answer: Aerobic cellular respiration

Aerobic cellular respiration uses oxygen in the electron transport chain to produce large amounts of ATP from glucose.