B1 - Cell Biology Flashcards
What’s a prokaryotic cell?
Give an exanple
Single cell organism
Bacteria
What’s a eukaryotic cell?
Give an example
Complex and include animal and plant cells
Name the parts (subcellular structures) of animal cell
Nucleus
Cytoplasm
Mitochondria
Cell membrane
Cytoplasm
Ribosomes
Function of a nucleus?
contains genetic material and controls activities of cell
function of mitochondria ?
where aerobic respiration takes place to provide energy that the cell needs
function of cytoplasm?
gel like substance where most chemical reactions happen
contains enzymes to control the reactions
function of cell membrane?
holds cell together and controls what goes in and out
function of ribosomes?
where proteins are made in the cell
name the parts of a plant cell that an animal cell doesn’t have
rigid cell wall
permanent vacuole
chloroplasts
function of rigid cell well?
made of cellulose, it supports and strengthens the cell
function of vacuole?
contains cell sap - a weak solution of sugar and salts
function of chloroplasts ?
this is where photosynthesis takes place, which makes food for the plant
what is the green substance in chloroplasts and what is its function?
chlorophyll and it absorbs the light needed for photosynthesis
what type of cell is bacteria?
prokaryote
what are the sub-cellular structures in bacteria?
singular strand of DNA (no nucleus) that floats freely in the cytoplasm
may have small rings of DNA called plasmids
cytoplasm
cell membrane
cell wall
what is the smallest thing you can see with a light microscope?
cells and large subcellular structures
which type of microscope has a higher magnification and resolution?
electron
formula for magnification
magnification = image size/real size
describe how to prepare a slide
1) drop water onto slide
2) separate the specimen into a small layer
3) place specimen into the water on slide
4) add a drop of iodine solution
5) add a cover slip on top
name parts of a light microscope
eyepiece
coarse adjustment knob
fine adjustment knob
light
stage
high and low power objective lenses
describe how to use a light microscope
1) clip slide on stage
2)select lowest powered objective lens
3) use coats adjustment knob to move stage up to objective lenses
4) look down in eyepiece and use coarse adjustment knob to move the stage down until image is in focus
5)adjust focus with fine adjustment knob until you get a clear image
6)if you need greater magnification, swap to a higher powered objective lens
what is differentiation ?
process by which a cell changes to become specialised for a job
what are undifferentiated cells called?
stem cells
where can you find stem cells in a plant, animal or embryo?
bone marrow
meristem
embryonic
name the function of a sperm cell and how it is specialised
function - take make DNA to female DNA
long tail and streamlined head to help it swim
lots of mitochondria for energy
enzymes in head to digest egg cell membrane
name function of a nerve cell and how it is specialised
function - carry electrical signals from
one part of body to another
long to cover distance
branches connections to connect and form a network
name the function of a muscle cell and how it is specialised
function - contract quickly
long (so they have space to contract)
lots of mitochondria to generate energy needed for contraction
name the function of a root hair cell and how it is specialised
function- absorb water and minerals
long to have a big surface area for absorbing water and mineral ions from the soil
what is the function of phloem and xylem cells and how are they specialised?
function - transport food and water around plants
long cells that form tubes by joining end to end
xylem - hollow in centre
phloem - very few subcellular structures
what can adult stem cells turn into?
only certain types, unless it is bone marrow in which case it can differentiate into everything
how can embryonic stem cells be used to cure disease?
can transfer to a patient to replace faulty cells, for example:
-insulin producing cells for people with diabetes
-nerve cells for paralysed people
what is a benefit of therapeutic cloning?
embryo would have the same genetic information as patient, and wouldn’t be rejected from the patients body
risk of stem cell use?
may become contaminated with a virus in the lab and passed onto patient
why are some people against stem cell research
they feel that human embryos shouldn’t be used for experiments since it is potential human life & shouldn’t be valued below others
how can stem cells be used to produce identical plants
use the stem cells in the meristem to grow more rare plants / plants with desired features
what do chromosomes contain?
genetic information
where are chromosomes found?
nucleus
what are chromosomes?
coiled up length of DNA molecule
how many pairs of chromosomes in a human cell?
23
what is the cell cycle?
process by which body cells in multicellular organisms divide to produce new cells
what is mitosis?
stage of cell cycle where cell divides
what is mitosis used for?
grow and develop / replace cells that are damaged
what are the stages of the cell cycle?
1) growth & dna replication
2) mitosis
describe steps of growth & dna replication
cell grows and increases number of subcellular structures
duplicates DNA so there’s a copy for new cell
describe steps of mitosis
1 - chromosomes line up at centre of cell & cell fibres pull them apart
2- membranes form around each set of chromosomes, becoming the new nuclei
3- cytoplasm and cell membrane divide
4 - now have 2 daughter cells with identical DNA
what is diffusion?
gradual movement of particles from a high concentration gradient to a low concentration gradient
