Crowdly

Which statement about collagen is correct?

It is found only in cartilage.

It is the least abundant ECM protein.

It is secreted as procollagen and assembled extracellularly.

Match each feature with the correct type of cell death

Cell shrinkage and membrane blebbing

DNA fragmentation into nucleosomal ladders

Plasma membrane rupture

Inflammatory response

Activation of caspases

Match each signaling type with its main feature

Synaptic

Juxtacrine

Paracrine

Autocrine

Endocrine

Morphogenetic

Why is the membrane potential important for cells?

It regulates the transport of ions and nutrients.

It enables excitability in nerve and muscle cells.

It provides energy for secondary active transport.

All the anwers are correct

It drives ATP synthesis in mitochondria and chloroplasts.

Which of the following statements about membrane transport is correct?

Passive transport requires ATP hydrolysis to move molecules down their gradient.

Facilitated diffusion requires transport proteins but no direct energy input.

Active transport always moves molecules down their electrochemical gradient.

Endocytosis is a form of passive transport.

Simple diffusion is selective and saturable, like carrier-mediated transport.

Which statement about the primary cilium is correct?

It is a non-motile sensory organelle, usually present as a single copy per cell.

It is a motile structure involved in cell swimming, like flagella.

It is important for Wnt signaling in vertebrates

It is made of actin filaments arranged in a 9+2 pattern.

It originates exclusively from the nucleus during mitosis.

It is important for Hh signaling in vertebrates

Which statement about kinesins and dyneins is correct?

Both kinesins and dyneins move toward the minus end

Kinesins move toward the minus end, dyneins toward the plus end

Kinesins display GTPase activity

Kinesins move toward the plus end, dyneins toward the minus end

Dyneins require ATP hydrolysis

Movement direction is random

Which of the following actin structures supports intestinal microvilli?

Cortical actin network

Filopodia

Bundled actin with villin and fimbrin

Stress fibers

Lamellipodia

What is treadmilling of actin filaments?

Complete disassembly of the filament

Simultaneous growth at both ends

Severing filaments by gelsolin

Switching between actin and tubulin

Growth at the plus end and loss at the minus end, maintaining steady length