4.1.1 cell structure Flashcards
label the animal cell
label the plant cell
label the bacterial cell
animal and plant cells are examples of e_____ cells
eukaryotic
bacterial cells are examples of p_____ cells
prokaryotic
• eukaryotic cells have a n_____
• prokaryotic DON’T have a n_____
nucleus
function of the nucleus?
• controls the activities of the cell
• contains DNA (genetic information)
function of cytoplasm?
liquid substance where chemical reactions occur
function of mitochondria?
site of aerobic respiration to release energy
function of ribosome?
site of protein synthesis
function of cell membrane?
controls the movement of substances in and out the cell
function of chloroplasts?
• site of photosynthesis
• contains chlorophyll, which absorb light
function of the cell wall?
provides strength to the cell
• in plants and algae, it is made of cellulose
• in bacteria, it is made of peptidoglycan (also called murein)
• in fungi, it is made of chitin
function of the singular strand of circular DNA in bacteria?
carry genetic information
function of the plasmid?
small rings of DNA
cells specialise by undergoing d______, gaining new sub-cellular structures to suit its role
differentiation
what type of cell is this and what is its function?
sperm cell - specialised to carry the male’s DNA to the egg cell during reproduction for successful reproduction
what type of cell is this and what is its function?
nerve cell - specialised to transmit electrical signals from one part of the body to another
DNA in eukaryotic cells is arranged into C…
chromosomes
The colour of chlorophyll is
green
Specialised cells
have a specific shape because they have a specific fucnction
A source of undifferentiated cells are
stem cells
How is a sperm cell specialised to suit its function?
they have a tail to swim and are packed with mitochondria
How is a red blood cell specialised to suit its function?
- no nucleus so that they can carry more oxygen
- have haemoglobin which carries the oxygen
- biconcave disc shape increases surface area to allow faster diffusion (of oxygen)
- thin membrane to reduce diffusion distance to allow faster diffusion (of oxygen)
How is a nerve cell specialised to suit its function?
they are long and insulated for carrying messages all over the body
How is a muscle cell specialised to suit its function?
have many mitochondria for aerobic respiration to release energy to allow the muscle to contract and relax
How is a root hair cell specialised to suit its function?
have a long thin projections which increase their surface area for absorption of water and ions from the soil
Xylem cells function is
to carry water and dissolved mineral ions around the plant from the roots
Plants lose water from their leaves in a process called
transpiration
How is a xylem cell specialised to suit its function?
Made of dead cells, organised into tubes and that are hollow. Side walls reinforced with lignin
Function of phloem in the plant
to carry sugars made in photosynthesis from the leaves all over the plant
How is a phloem cell specialised to suit its function?
Phloem cells are living, contain few organelles and their end walls have small holes in them
What term is used to describe how sugar is moved around the plant
translocation
Muscles are specialised to allow for c…
contraction
Sperms cells are important for r…
reproduction
Nerves cells are specialised to …
carry electrical impulses around the body
name the cell
muscle cell
name the cell
root hair cell
Name the cells that make up the tubes on the left
Xylem
Name the cells that make up the tubes on the right
phloem
To prepare a cell for viewing you need
a glass slide, cover slip and a stain
Magnification is
how much bigger the object appears under the microscope
How do you calculate total magnification
magnification of eye piece lens x magnification of objective lens
Why does the specimen have stain placed upon it before covering with a cover-slip?
to stain the cell organelles so that we can view it better under the microscope
Name the two types of microscopes
light and electron microscope
Electron microscopes are better than light microscopes because
they have a greater magnification and resolution
Resolution is
the ability to distinguish two points as separate
1mm is equal to how many um
1000um
1m is equal to how many mm
1000mm
If a cell is actually 60um and the image is 45000um , what is the magnification?
45000/60 = x750
if a cell is 50um and the image is 25mm what is the magnification?
25,000/50 = x500
How many nm in 1mm
1,000,000nm
How many um in 1000nm
1um
The job of a microscope is to
magnify the object
Ability to distinguish as 2 points as separate is called
resolution
electron microscopes use
electrons
light microscopes use
light
Electron microscopes are better than light microscopes because…
they allow you to see much smaller things in more detail e.g. mitochondria
The higher the resolution, what happens to the image?
its sharper
A specimen that is 50um wide is magnified 100x, how much bigger is the specimen now?
5000um = 5mm
Why should you avoid air bubbles when preparing a glass slide for viewing?
obstructs view of specimen
What is a specimen?
the cells you are looking at
Why do you stain the cells you are viewing under a microscope?
stains highlight objects within the cell by adding colour to them
