Unit 4.1.1 Cell Structure Flashcards
animal and plant cells are examples of E..
Eukaryotes
Eukaryotes are complex organisms often described as M
Multicellular
Bacterial cells are P…
prokaryotes
Prokaryotic cells do not have…
a nucleus or mitochondria
prokaryotic cells compared to eukaryotic cells are
smaller, single celled, have rings of DNA called plasmids
Groups of bacterial cells are called
colonies
What does an animal cell not have that a plant cell has?
cell wall, vacuole and chloroplasts
Function of the cell membrane
controls what enters and leaves the cell
Function of the nucleus
Controls the cells activities and contains the genetic material (DNA)
Function of the cell wall
Provides support to the plant, made of cellulose
Function of bacterial plasmids
provide bacteria with variation - usually conferring antibiotic resistance
Function of the ribosomes
protein synthesis - its a very small organelle
Function of the mitochondria
Site of respiration, energy is released here
Describe the feature of bacterial DNA
Circular/loop, not arranged into chromosomes and not found in a nucleus
All eukaryotic cells have
a nucleus
An organelle is
a part of the cell with a specific function
The cytoplasm
is mainly water and is where the chemical reactions occur
Substances move in and out of cells by
diffusion
In exchange of materials between cells and their environment, substances must cross the
cell membrane
All our cells require
glucose and oxygen
All our cells carry out a process called R…
respiration
We can view cells using a
light microscope
Respiration is
is a chemical reaction that occurs inside all your cells to release energy
DNA in eukaryotic cells is arranged into C…
chromosomes
Plants have chloroplasts because
they need to photosynthesise
The function of the chloroplasts are
to trap light energy for photosynthesis
Photosynthesis is
when plants trap light energy and react carbon dioxide and water to produce glucose and oxygen
The colour of chlorophyll is
green
chlorophyll is found in the
chloroplast
cell wall is made of
cellulose
To prepare a cell for viewing you need
a glass slide, cover slip and a stain
The specimen when viewing under the microscope needs to be thin because
it needs to allow light to pass through it
Specialised cells
have a specific shape because they have a specific fucnction
A cell becomes a specialised cell because it has d…
differentiated
A source of undifferentiated cells are
stem cells
Examples of specialised animal cells
red blood cells, sperm cells, nerve cell, muscle cell
Examples of specialised plant cells are
root hair cell, palisade cells, xylem cell, phloem cell
Sperms are adapted because
they have a tail to swim and are packed with mitochondria
Red blood cells are adapted because
they have no nucleus so that they can carry more oxygen, They also have haemoglobin which carries the oxygen
Nerve cells are adapted because
they are long and insulated for carrying messages all over the body
Muscles cells are adapted because they
have many mitochondria in order to allow the muscle to contract and relax
Root hair cells are adapted because they
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
Describe how xylem cells are arranged
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
Describe how phloem cells are arranged
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
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
1000,000nm
How many um in 1000nm
1um
cell wall is made of
cellulose
green pigment in the chloroplast is called
chlorophyll
Function of the chlorophyll
absorb sunlight
Prokaryotes like bacteria are
single celled organisms
Building blocks of life are called
cells
Bacterial cell and a plant cell BOTH have
cell wall, cell membrane and cytoplasm
small rings of DNA in a bacterial cell are called
plasmids
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
0.017 written in standard form is
1.7 x 10-2
12000 written in standard from is
1.2 x 104
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
Muscles are specialised to allow for c…
contraction
Sperms cells are important for r…
reproduction
Function of phloem cells
to carry sugars around the plant
Nerves cells are specialised to …
carry electrical impulses around the body
Which label shows the chloroplast?
E
What is B pointing to in the cell?
cytoplasm
Which part of the cell controls what enters and leaves the cell?
A
Which label controls the cell activities?
C - nucleus
Which label gives the plant cell its stength and support and is made of cellulose?
D cell wall
Which label in the plant cell stores cell sap?
F -vacuole
Fill in the missing label on the bacterial cell
plasmid
Filling in the missing word on the formula triangle
magnification
Filling in the missing word on the formula triangle
image size
Filling in the missing word on the formula triangle
real/actual size
name the cell
nerve cell
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
