GCSE Biology- B1 Cell Biology

sub-cellular structure of animal cells

cell membrane, nucleus, cytoplasm, ribosomes, mitochondria

sub-cellular structure of plant cells

cell membrane, nucleus, cytoplasm, ribosomes, mitochondria, cell wall, chloroplast, vacuole

sub-cellular structures of bacteria cells

cell membrane, cytoplasm, ribosomes, chromosomes, cell wall, flagella, plasmid

Specialised cells

Cells that are adapted to carry out a particular function

examples of specialised cells

Sperm cells, nerve cells, muscle cells, root hair cells, phloem cells, xylem cells, guard cells, skin cells, palisade cell, epithelial cells, guard cells

root hair cells

Cells in the end of roots that have long extensions to increase surface area for the absorption of water and minerals.

organ

Collection of tissues working together to perform a function e.g. stomach.

Tissue

A group of similar cells that perform the same function.

cell

The basic unit of structure and function in living things

cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell

where are cell walls found

plants and bacteria cells

cell membrane

A cell structure that controls which substances can enter or leave the cell.

Nucleus

sub-cellular substructure containing DNA

ribosomes

site of protein-synthesis

mitochondria

Site of respiration

Chloroplast

Site of photosynthesis

Where does photosynthesis happen?

Chloroplast

What makes plants green?

chlorophyll

Where can mitochondria be found?

plant and animal cells

where can ribosomes be found?

plant, bacteria and animal cells

Cytoplasm

Site of chemical reactions

Vacuole

Contains cell sap

Flagella

whiplike tails found in one-celled organisms to aid in movement

where can the vacuole be found

plant cells

function of epithelial tissue

Protect the stomach by covering the inner and outer part of it.

function of muscle tissue

Contract for movement. This churns the food.

function of glandular tissue

Produce acid and enzymes

adaptation of muscle tissues

lots of mitochondria to allow contraction in muscle

adaptation of nerve cells

lots of mitochondria to carry impulses around body

adaptation of sperm cells

long tail to to carry fathers DNA to egg cell

what are the 2 types of microscopes?

light microscope and electron microscope

which microscope has a higher magnification?

electron microscope

What advantage does an electron microscope have over a light microscope?

can see cells in better detail and see sub-cellular structures

which microscope has higher resolution?

electron microscope

Formula for photosynthesis

6CO2 + 6H2O -> C6H12O6 + 6O2

Formula for magnification

magnification = image size/actual size

1cm

10mm

1mm

1000um (micrometers)

1um (micrometer)

1000nm (nanometers)

Why did you sterilise the petri dish before using it? (RP2)

to kill unwanted bacteria

Why was the inoculating loop put in a flame? (RP2)

To kill any unwanted bacteria.

3 stages of cell cycle

Cell growth, Copying of chromosomes and mitosis

cell growth phase

process by which a cell increases its size and increase in organelles

copying of chromosome phase

An identical copy of each chromosome is made

mitosis phase

Identical chromosomes are pulled to opposite ends of the cell, nucleus divides, cytoplasm and cell membrane divides, two identical cells are produced

why is mitosis important?

Used for growth and repair of damaged cells

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

active transport

movement of particles against the concentration gradient (low to high concentration).

osmosis

movement of water particles from an area of high water concentration to low water concentration through a partially permeable membrane

Differentiation

process in which cells become specialised for a specific function

stem cells

Unspecialised cells which can differentiate into different types of cells

where can stem cells be found in humans?

Human embryos or from adult bone marrows.

Why are scientists experimenting with stem cells?

for medical treatments and medical research

embryonic stem cells

stem cells from an early embryo that can differentiate to any cell but is only possible if sperm and egg cell meet

adult stem cell

A cell present in adult tissues that generates replacements for nondividing differentiated cells