topic 1:key concepts(cells) Flashcards
examples of eukaryotic cells and structures
animal and plant cells, they have a cell membrane, cytoplasm and nucleus.
example of prokaryotic cell and structures
bacteria cells, they have cell wall, cell membrane, cytoplasm and single circular stranded DNA or plasmids.
function of the nucleus
contains DNA coding for proteins needed to build new cells and its enclosed in a nuclear membrane
function of the cytoplasm
where chemical reactions occur, contains enzymes and organelles.
function of the cell membrane
controls what enters and leaves the cell.
function of mitochondria
where aerobic reactions occur, provides energy for the cell.
function of ribosomes
where protein synthesis occurs
function of chloroplasts
where photosynthesis occurs and provides food, contains chlorophyll
function of cell wall
provides strength to the cell, made from cellulose
what and how are sperm cells specialised to do
specialised to carry male DNA to the egg cell, adaptations: streamlined head, many mitochondria, acrosome to break down layers of egg and haploid nucleus.
what and how are egg cells specialised to do
specialised to accept a single sperm cell and develop an embryo, adaptations: surrounded by cell membrane that becomes impermeable when fertilised, lots of mitochondria and large size and cytoplasm for quick repeated division when embryo grows.
what and how are ciliated epithelial cells to do
long hair like cilia trap bacteria with sticky mucus down to stomach to be killed.
what and how are root hair cells specialised to do
they take up water by osmosis and mineral ions by active transport, they have a large surface area, a permanent vacuole and lots of mitochondria.
what and how are xylem cells specialised to do
they transport water and mineral ions from root to shoots, lignin is deposited which causes cells to die, they becomes hollow and are joined end to end to form a continuous tube.
what and how are phloem cells specialised to do
form sieve plates to allow movement from cell to cell.
