AQA Biology Third Edition Flashcards

Flashcards covering the topics discusses in the provided textbook notes.

Cell

The basic building block of all living things.

Nucleus

Controls all the activities of the cell and contains the genes on the chromosomes.

Cell membrane

Controls the passage of substances into and out of the cell.

Mitochondria

Structures in the cytoplasm where aerobic respiration takes place, releasing energy for the cell.

Ribosomes

Where protein synthesis takes place, making all the proteins needed in the cell.

Cell wall

Made of cellulose, strengthens the cell and gives it support.

Chloroplasts

Found in the green parts of a plant and contain chlorophyll. Absorb light so the plant can make food by photosynthesis.

Permanent vacuole

Space in the cytoplasm filled with cell sap. This is important for keeping the cells rigid to support the plant.

Eukaryotic cells

Cells that have a cell membrane, cytoplasm, and genetic material that is enclosed in a nucleus.

Prokaryotic cells

Cells that contain cytoplasm and a cell membrane surrounded by a cell wall. The genetic material is not enclosed in a nucleus.

Plasmids

Small rings of DNA found in prokaryotic cells that code for very specific features such as antibiotic resistance.

Differentiation

Cells become specialized to perform particular jobs, resulting in specialized cells with different sub-cellular structures to carry out specific functions.

Nerve cells

Specialized to carry electrical impulses around the body.

Muscle cells

Specialized cells that can contract and relax.

Sperm cells

Contain the genetic information from the male parent and are adapted to move through water or the female reproductive system to reach an egg.

Root hair cells

Cells near the tips of growing roots that increase the surface area for water to move into the cell.

Xylem

The transport tissue in plants that carries water and mineral ions from the roots to the highest leaves and shoots.

Pholem

The specialized transport tissue that carries the food made by photosynthesis around the body of the plant.

Diffusion

The spreading out of the particles of a gas, or of any substance in solution, resulting a net movement of particles from an area of higher concentration to an area of lower concentration.

Partially permeable membranes

Membranes that only let some types of particles through.

Osmosis

A special type of diffusion, where only water moves across a partially permeable membrane from a dilute solution to a concentrated solution.

Isotonic

The concentration of solutes in the solution outside the cell is the same as the internal concentration

Hypertonic

The concentration of solutes in the solution outside the cell is higher than the internal concentration.

Hypotonic

The concentration of solutes in the solution outside the cell is lower than the internal concentration.

Turgor

The pressure that makes the cells hard and rigid.

Active transport

Allows cells to move substances from an area of low concentration to an area of high concentration, against the concentration gradient.

Surface area to volume ratio

The ratio of surface area to volume makes a big difference to the way animals can exchange substances with the environment and how energy is transferred by living organisms.