AQA Biology GCSE Topic 1: Cell Biology Flashcards

Flashcards for AQA Biology GCSE Topic 1: Cell Biology

Cells

All living things are made of these, which can either be prokaryotic or eukaryotic.

Eukaryotic

Animal and plant cells are this type, characterized by having a nucleus containing DNA.

Prokaryotic

Bacterial cells are this type and are much smaller, containing a single circular strand of DNA and plasmids.

Organelles

Structures in a cell that have different functions, such as the cell membrane.

Centi

Prefix that multiplies a unit of measurement by 0.01.

Milli

Prefix that multiplies a unit of measurement by 0.001.

Micro

Prefix that multiplies a unit of measurement by 0.000,001.

Nano

Prefix that multiplies a unit of measurement by 0.000, 000, 001.

Nucleus

Contains DNA coding for a particular protein needed to build new cells and is enclosed in a nuclear membrane.

Cytoplasm

Liquid substance in which chemical reactions occur, containing enzymes and organelles.

Cell membrane

Controls what enters and leaves the cell.

Mitochondria

Where aerobic respiration reactions occur, providing energy for the cell.

Ribosomes

Where protein synthesis occurs and is found on the rough endoplasmic reticulum.

Chloroplasts

Where photosynthesis takes place, providing food for the plant, and contains chlorophyll.

Permanent vacuole

Contains cell sap and improves the cell’s rigidity.

Cell wall

Made from cellulose and provides strength to the cell.

Differentiation

Process that involves the cell gaining new sub-cellular structures in order for it to be suited to its role.

Sperm cells

Specialized to carry the male’s DNA to the egg cell for successful reproduction, aided by a streamlined head and long tail.

Nerve cells

Specialized to transmit electrical signals quickly from one place in the body to another, featuring a long axon and dendrites.

Myosin and actin

Specialized proteins in muscle cells that slide over each other, causing the muscle to contract.

Root hair cells

Specialized to take up water by osmosis and mineral ions by active transport from the soil.

Xylem cells

Specialized to transport water and mineral ions up the plant from the roots to the shoots, forming a continuous tube through hollow dead cells.

Phloem cells

Specialized to carry the products of photosynthesis (food) to all parts of the plant, with sieve plates facilitating movement between cells.

Adult stem cells

Cells that retain the ability to undergo differentiation, replacing cells such as red blood cells that cannot divide.

Light microscope

Microscope that uses two lenses (objective and eyepiece) to view tissues, cells, and large sub-cellular structures.

Electron microscope

Microscope that uses electrons to form an image, enabling scientists to view deep inside sub-cellular structures.

Culturing Microorganisms

Method used to grow microorganisms in the lab by using nutrients.

In nutrient broth solution

A way to grow microorganisms that involves making a suspension of bacteria to be grown and mixing with sterile nutrient broth.

On an agar gel plate

A way to grow microorganisms that involves agar acting as the culture medium, and bacteria grown on it form colonies on the surface.

Binary fission

Process where bacteria multiply by one splitting into two.

Inhibition zone

The clear area around antibiotic discs that shows how many bacteria have died, indicating how effective the antibiotic is.

Chromosomes

Contains your genetic information in the form of DNA coils.

Gene

A short section of DNA that codes for a protein and as a result controls a characteristic.

Interphase

The stage when the cell grows, organelles grow and increase in number, the synthesis of proteins occurs, DNA is replicated and energy stores are increased

Cytokinesis

Two identical daughter cells that form when the cytoplasm and cell membranes divide

Stem cell

An undifferentiated cell which can undergo division to produce many more similar cells, of which some will differentiate to have different functions.

Embryonic stem cells

Stem cells Formed when an egg and sperm cell fuse to form a zygote

Meristems in plants

Found in root and shoot tips; Can differentiate into any type of plant, and have this ability throughout the life of the plant

Therapeutic cloning

Involves an embryo being produced with the same genes as the patient

Diffusion

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

Gas exchange

The movement of gases is called

Osmosis

Water is able to move across cell membranes by

Mitosis

The stage when the cell divides during the cell cycle

Root hair cells

Cells found in the tips of roots that have a large surface area, meaning more water can move in

Osmosis

The movement of water from a less concentrated solution to a more concentrated one through a partially permeable membrane

Water potential

Water moves from a dilute solution to a concentrated solution because it moves from an area of high to low - down the concentration gradient

Hypotonic

Animal cell swells and bursts

Isotonic

If the concentration of sugar in external solution is the same as the internal, there will be no movement and the solution is said to be __ to the cell

Hypertonic

If the concentration of sugar in external solution is higher than the internal, water moves out, and the solution is said to be __ to the cell

Hypotonic

If the concentration of sugar in external solution is lower than the internal, water moves in, and the solution is said to be __ to the cell

Turgor

Pressure that results with the cell swelling when water moves into the cell and into the vacuole

Plasmolysis

When the cell membrane will move away from the cell wall and it will die

Active transport

The movement of particles from an area where they are in lower concentration to an area where they are in higher concentration- against their concentration gradient