AP Biology Fall 2024 Semester Exam Review

Front

What is the structure of the phospholipid bilayer in cell membranes?

Back

The phospholipid bilayer consists of two layers of phospholipids, with hydrophilic (polar) heads facing outward and hydrophobic (nonpolar) tails facing inward, creating a semi-permeable membrane.

Front

Why can't ions pass through the phospholipid bilayer?

Back

Ions cannot pass through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic, preventing charged particles from crossing.

Front

What is the role of steroid hormones in cellular signaling?

Back

Steroid hormones pass through the plasma membrane and bind to intracellular receptors, forming a hormone-receptor complex that can enter the nucleus and promote transcription of specific genes.

Front

What is the outcome of steroid hormone signaling in cells?

Back

The binding of steroid hormones to their receptors increases the production of specific mRNA, leading to the synthesis of proteins that regulate various cellular functions.

Front

What is a physiological saline solution and its purpose?

Back

A physiological saline solution (0.9% sodium chloride) is isotonic to human blood, used to quickly rehydrate patients by maintaining osmotic balance.

Front

What happens to red blood cells in an isotonic solution?

Back

In an isotonic solution, the rate of water movement into red blood cells equals the rate of water movement out, maintaining cell shape and function.

Front

What is a unique feature of prokaryotic cells, such as bacteria and archaea?

Back

Prokaryotic cells do not have a nuclear membrane surrounding their genetic material, allowing direct access to the cytoplasm.

Front

What distinguishes light-dependent reactions from light-independent reactions in photosynthesis?

Back

Light-dependent reactions produce ATP and NADPH using light energy, while light-independent reactions (Calvin cycle) use ATP and NADPH to synthesize glucose.

Front

What are the two main types of reactions in photosynthesis?

Back

The two main types of reactions in photosynthesis are light-dependent reactions (occur in thylakoid membranes) and light-independent reactions (occur in the stroma of chloroplasts).

Front

What is the function of ribosomes in cells?

Back

Ribosomes are the cellular machinery responsible for protein synthesis, translating mRNA into polypeptide chains.