SEARCH
You are in browse mode. You must login to use MEMORY

   Log in to start

Biology GCSE

Images from Storyboardthat.


🇬🇧
In English
Created:
Biology GCSE


Public
Created by:
Samuel Obigbesan


4.2 / 5  (5 ratings)



» To start learning, click login

1 / 25

[Front]


What is a cell?
What is a cell?
[Back]


The basic unit of life

Practice Known Questions

Stay up to date with your due questions

Complete 5 questions to enable practice

Exams

Exam: Test your skills

Test your skills in exam mode

Learn New Questions

Popular in this course

Learn with flashcards
multiple choiceMultiple choice mode
TypingTyping only mode

Dynamic Modes

SmartIntelligent mix of all modes

Manual Mode [BETA]

The course owner has not enabled manual mode
Other available modes

SpeakingAnswer with voice

Biology GCSE - Details

Levels:

Questions:

242 questions
🇬🇧🇬🇧
What is a cell?
The basic unit of life
What subcellular structures are found in the animal cell?
Nucleus, Cytoplasm, Cell Membrane, Mitochondria, Ribosomes
What does the nucleus do?
Contains genetic material that controls the cell's activity
What does the cell membrane do?
Holds the cell together, is semi-permeable to allow certain substances to go in and out of the cell, and is a barrier that stops the cytoplasm seeping out
What does the mitochrondria do?
This is the powerstation of the cell and releases energy from glucose in aerobic respiration
What does the ribosome do?
It is used for protein synthesis.
What is a cell wall function?
A rigid structure made up of cellulose to strengthen and support the cell.
What is the job of a permanent vacuole?
A bag filled with cell sap, which is a weak solution of sugar and salt
What is the job of a chloroplast?
It contains a green pigment called chlorophyll that is used for photosynthesis, which makes food of the plant. Chlorophyll also absorbs sunlight and is not found under the soil.
What is a eukaryotic cell?
They have genetic information contained in their nucleus with cytoplasm and cell membrane.
What is a prokaryotic cell?
They do not have genetic information contained in their nucleus with cytoplasm and cell membrane
What are plasmids?
Small loops of DNA
What type of cell division do bacteria cells undergo and what happens during it? (DIFFICULT)
Binary fission and the cells copy their strand of DNA and then it spits in the middle to make two.
What is magnification?
How much bigger the image than the actual specimen
What is resolution?
Ability to distinguish between two point
What is a microscope?
An instrument used to study very small objects with our naked eyes.
What is a light microscope?
Device that uses visible light and a series of lenses to produce an enlarged image of an object.
What are the disadvantages of a light microscope?
Low magnification, low resolution
What is an electron microscope?
Device that uses electrons and a beam of them to produce an enlarged image of an object.
What are the advantages of an electron microscope
More detailed, 2,000,000x magnification, TEM most detail 2D, SEM 3D, allows you to see internal structures in the cell like the ribosomes, the nucleus, and the chloroplasts in plants.
What are the disadvantages of electron microscope?
Very expensive, not portable, and have to have a thin coating of metal added before they are put in the vacuum chamber.
What is the equation for total magnification?
Total magnification = eyepiece lens x objective lens
How would you create an animal cell slide?
1. Using a cotton bud, swab the inside of your cheek to extract cells 2. Rub the cotton bud onto the centre of the clean microscope slide 3. Add a drop of methylene blue stain 4. Using a mounted needle, slowly lower a coverslip over the stain 5. View under a microscope at low power and then increase the magnification. Add the total magnification
How would you create a plant cell slide?
1. Using tweezers, peel off a single onion layer of onion skin 2. Lay flat on top of a clean microscope slide 3. Add a drop of iodine 4. Using a mounted needle, slowly lower a coverslip over the stain 5. View under a microscope at low power and then increase the magnification. Add the total magnification
What is the job of the stage?
It is where you position your specimen under a microscope slide. It can be moved up and down.
What is the job of the light in a light microscope?
A light source that is built in to have a bulb inside already. Some times, you may have a mirror instead and you would have to place it on top of a deak near a window to reflect light.
What is the objective lens in a light microscope
A curved piece of glass that makes the specimen appear bigger. They vary in their magnifying strength usually around x10 -> x40 on a school light microscope.
What is the job of the eyepiece lens?
This is the lens at the top you look through with a magnification of x10.
What does the coarse focus do?
It moves the stage up and down
What does the fine focus do?
It is the more precise focus.
What is a coverslip?
A square of thin, transparent plastic or glass
What is iodine solution used for in light microscope for cells?
To highlight objects in a cell by adding colour to them
How would you set up a light microscope by preparing your slide?
1. A dd a drop of water to the centre of a clean slide 2. Cut onion and separate it into layers out. Use tweezers to peel off some epidermal tissue from the bottom of one of the layers 3. Using tweezers, place the epidermal tissue into the water on the slide 4. Add a drop of iodine 5. Place a coverslip on top.
What is eosin for?
Used to make the cytoplasm show up
How would you set up and use the light microscrope?
1. Clip the slide that been prepared onto the stage 2. Select the lowest-powered objective lens first. This gives the lowest magnification. 3. Use the coarse adjustment knob to move the stage just under the objective lens 4. Look through the eyepiece. Use the coarse adjustment knob until the stage downwards until the image is roughly in focus 5. Adjust the focus with the fine focus knob, until there is a clear image on the slide 6 Use the higher-powered objective lens and refocus to see a slide with greater magnification
Name a rule for using low power and high power drawings?
Use a sharp pencil to draw smooth lines
A bacteria cell measures 5μm in length. Calculate the magnification of the image. (don't zoom in on the image)
To measure image size, you measure its length across with a ruler. You also need to convert it to μm 56,000μm/5μm = 11200x
What is specialised cells?
Cells that have developed certain characteristics to perform a particular function.
What are sperm cells?
They travel towards and fertilise the egg
What organelle can be found in the animal cell?
Nucleus, cell membrane, ribosome, mitochondria, and cytoplasm
What is the job of the acrosome in the sperm cell?
Contains enzymes to breaks through the egg's outer layer
What are nerve cells for?
Conduct electrical impulses
What are axons features?
Conduct electrical impulses in one direction
What are myelin sheath for?
Insulate the impulse
What are the job of synapses?
Sends neurotransmitter chemical to another nerve cell or effector
What are muscle cells?
Special proteins that slide past each other making muscle fibres contract
Why would muscle cell require lots of mitochrondria?
To transfer energy for these contractions
Why would there be glycogens in muscle cells?
To store energy in the form of glucose
What organelle can be found in the plant cell?
Nucleus, cell membrane, ribosome, mitochondria, cytoplasm, cell wall, vacuole and chloroplast
How does a plant cell do its job for photosynthesis?
It does photosynthesis by trapping sunlight to make food
What are root hair cells job?
Absorb water and mineral ion from the soil
Why do root hair cells have no chloroplasts?
The root hair cells are underground and sunlight will not reach them
Why do root hair cells have long hair-like extension?
To increase surface area for absorption
Why would root hair cells have many mitochondria?
To fuel the active transport of mineral into the cell
What is a xylem cell needed for?
Transport water and mineral ions from from the roots to the leaves
What is xylem made from?
Made from cells that have died and the cell wall is broken between them forming hollow tubes
What is a phloem needed for?
Transport the products of photosynthesis (glucose) from the leaves to the rest of the plant
What is a phloem made from?
Made from living cells where the cell wall has been broken down between cells to form sieve plates that allow sugar to flow freely by translocation
Where are companion cells found on a plant?
On the side of a phloem cell that have many mitochondria to transfer energy to phloem cell
What is a transpiration stream
A stream where water and dissolved mineral ion get transported from the xylem to the leaf
What are stomata?
Tiny holes that control gas exchange in leaves
What is the order of cellular organisation with nerve cells?
Nerve cells, nerve tissue, heart, circulatory system, human
What is a cell?
The building block of life