Cell Structure and Function

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What is the orientation of phospholipid molecules in the plasma membrane?

Hydrophobic tails on both sides and hydrophilic heads in the middle
Hydrophobic tails inside and hydrophilic heads outside (correct)
Hydrophilic heads on both sides and hydrophobic tails in the middle
Hydrophobic tails toward the outside and hydrophilic heads inside

What prevents polar substances from crossing the plasma membrane?

The presence of glycophospholipids
The nonpolar nature of the hydrophobic ends (correct)
The presence of pores in the nuclear envelope
The hydrophilic nature of the phospholipid heads

What is the function of glycophospholipids embedded in the plasma membrane?

To synthesize proteins
To store genetic information
To regulate cell growth
To transport molecules across the membrane (correct)

What is the purpose of the nuclear envelope's pores?

To allow molecules to move between nucleus and cytoplasm (A) Signup and view all the answers

What is the function of rough endoplasmic reticulum (RER)?

To synthesize proteins that are involved in all of the above (D) Signup and view all the answers

Where are lipids and phospholipids synthesized?

In the Golgi complex (D) Signup and view all the answers

What is the primary function of microvilli in the intestine?

To increase the surface area of the tissue (D) Signup and view all the answers

What is the main difference between plants and animals in terms of nutrition?

Plants are autotrophic, while animals are heterotrophic (D) Signup and view all the answers

What is the primary function of the plasma membrane?

To act as a selective gatekeeper (A) Signup and view all the answers

What type of interactions are responsible for membrane function?

Hydrophilic and hydrophobic interactions (B) Signup and view all the answers

What is the permeability of artificial membranes composed of pure phospholipid or phospholipid and cholesterol?

Permeable to gases and small molecules, but impermeable to water and hydrophilic molecules (C) Signup and view all the answers

What is the function of transport proteins in the membrane?

To regulate the movement of substances into the cell (A) Signup and view all the answers

What is the primary function of transporter proteins in cells?

To specifically bind to substrate molecules and facilitate their transport (A) Signup and view all the answers

Which type of molecules can cross the cell membrane through diffusion?

Lipid-soluble molecules, gases, and urea (A) Signup and view all the answers

What is the difference between facilitated diffusion and active transport?

Active transport requires energy, while facilitated diffusion does not (D) Signup and view all the answers

What is the purpose of gated channels in the cell membrane?

To regulate the flow of charged substances (B) Signup and view all the answers

How do voltage-gated channels open or close?

When the ionic charge across the membrane changes (D) Signup and view all the answers

What is the direction of facilitated diffusion?

With the concentration gradient (B) Signup and view all the answers

What is the characteristic of antiporter kinetics?

Simultaneous transport of substrates in both directions (B) Signup and view all the answers

What is the function of adenine nucleotide translocase in the mitochondria?

To catalyze 1:1 exchange of ADP for ATP across the inner mitochondrial membrane (B) Signup and view all the answers

What is the direction of diffusion?

From an area of high concentration to an area of low concentration (D) Signup and view all the answers

What is the effect of a steeper concentration gradient on the diffusion rate?

Faster diffusion rate (A) Signup and view all the answers

Which of the following molecules can diffuse directly through the lipid bilayer?

Oxygen (C) Signup and view all the answers

What is the requirement for simple diffusion?

No use of transport proteins (D) Signup and view all the answers

What is the outcome of meiosis?

Four haploid daughter cells (D) Signup and view all the answers

During which stage of meiosis do homologous chromosomes separate?

Anaphase I (C) Signup and view all the answers

What is the stage of meiosis immediately preceding cytokinesis?

Telophase II (A) Signup and view all the answers

During which stage of meiosis do sister chromatids separate?

Anaphase II (C) Signup and view all the answers

How many chromosomes are present in the daughter cells of meiosis I?

Half the number of the parent cell (B) Signup and view all the answers