Biology Flashcards
What organelles make up an animal cell?
Nucleus Cytoplasm Cell membrane Mitochondria Ribosomes
What organelles make up a plant cell?
Chloroplast Chlorophyll Permanent Vacuole Ribosomes Cell membrane Nucleus Cell wall Cytoplasm Mitochondria
What do chloroplasts do?
They photosynthesise
What do mitochondria do?
They release energy by respiration
What do ribosomes do?
They protein synthesis
What does a nucleus do?
They control cell activities
What does a vacuole do?
They help keep cell rigid
What does a cell membrane do?
They control movements of substances into and out of cell.
Give an example of a specialised cell?
Ciliates cell
Neurone
White blood cells
Etc
What is a specialised cell?
A cell that has its own job to do. These cells have special features that allow them to perform their functions effectively.
What is a stem cell?
Undifferentiated cells that can turn into any specialised cell in your body.
What is a nerve cells function?
To carry nerve impulses around your body.
What is a sperm cells function?
To carry the fathers genetic information (DNA) to the egg.
What is a ciliated cells function?
Designed to stop lung damage so the hairs sweep mucus with trapped dust and bacteria back up the throat to be swallowed. Smoke damages them.
What is the function of a muscle cell?
To contract to move bones
What is the function of a red blood cell?
It carries oxygen from the lungs to the body and carbon dioxed from the body back to the lungs.
What makes a nerve cell special?
It is long and has long branches to connect to other nerves. The long axis is covered in fat to increase the speed of electrical signals.
What makes a sperm cell special?
It has a long tail to find an egg. The enzymes in the head help to get into the egg. It is made in the testis of males.
What makes a ciliated cell special?
They line all the air passages down to the lungs. They have tiny hairs called cilia.
What makes a muscle cell special?
They contain proteins that slide over each other making the fibres contract.
Mitochondria issued to transfer energy needed for chemical reactions to take place as the cell contracts and relaxes.
What makes red blood cells special?
They have a large surface area because of the dimple shape.
It contains haemoglobin which pick up oxygen but has no nucleus to make room for more oxygen.
Give an example of a eukaryotic cell.
Animal and plant cells
Give an example of a prokaryotic cell.
Bacteria
Are red blood cells a eukaryotic or prokaryotic cell?
Red blood cells don’t have a nucleus but it is an animal cell so it is a eukaryote.
What is the difference between a eukaryote and a prokaryote?
Eukaryotes have a nucleus, the DNA is found in the nucleus whereas, prokaryotes don’t have a nucleus so the DNA is free floating not in a nucleus.
What are ciliated cells?
They are small hairs that sweep up dust and bacteria so they don’t enter the lungs.
What does DNA look like?
a double-helix
Which type of cell is the oldest and simplest?
Prokaryotes
Which type of cell is bigger and more complex?
Eukaryotes
What is a benefit of having DNA housed in a nucleus?
Protects the DNA
What is a flagellum?
A tail like structure, to help it move
Why do we use a mirror on a light microscope?
It is to reflect light up through the bottom of the stage to help magnify objects whilst obtaining a sharp image.
What is the equation for magnification?
size of image divided by size of real object
Why are light microscopes in colour?
because you need light to see them
Why are light microscopes in colour?
because you need light to see them, whereas electron microscopes are in black and white but are much more detailed
Give a disadvantage to using an electron microscope?
They are large and very expensive, and have to be kept in special temperature, pressure and humidity.
Why do root hair cells not have chloroplasts?
It is underground and doesn’t photosynthesis.
Why does a root hair cell have a large permanent vacuole?
It speeds up the movement of water, from the soil into the cell.
What is the purpose of having the root hair tail thing on a root hair cell?
It increase the surface area to absorb more water from the soil.
Why does a palisade cell contain lots of chloroplasts?
To perform photosynthesis
Where are palisade cells located?
Found in leaves
Layered to absorb lots of light
In the green part of the plant-leaves, outer layer of green stem
What is the use of a permanent vacuole in a palisade cell?
To maintain structure-it’s rigid shape
Why do leaves remain flat?
To increase photosynthesis
What does a xylem cell do?
Transports water around the plant
What do the tubes in xylem cells do?
Carry water through the plant
What forms spirals around the cells in a xylem cell?
Lignin
What is the use of lignin spirals in a xylem cell?
To provide solid support for the tubes to withstand water pressure
What does a phloem cell do?
It carries sugars dissolved in water
How are sieve plates formed in a phloem cell?
Formed when cell walls break down.
What is the use for sieve plates in a phloem cell?
To allow food to travel around the plant
What does the mitochondria in the companion cell provide the phloem cell with?
Energy needed to survive
What is diffusion?
The movement of particles from a high concentration to a low concentration.
How is diffusion caused?
By the random movement of particles
What does net movement of particles mean?
Particles moving in and out
When you increase temperature what happens to the particles?
They move more, which speeds up diffusion
Where does diffusion occur?
In the lungs and intestines
How does diffusion happen in the lungs?
Oxygen diffuses in, carbon dioxide diffuses out
How are cells adapted to increase diffusion rates?
By increasing the surface area
What is concentration gradient?
It is the difference between 2 areas of concentration.
What substances can diffuse into and out of cells?
Simple sugars, such as glucose and gases such as oxygen and carbon dioxide, and waste products such as urea from the breakdown of amino acids in your liver.
What is urea?
It passes from the liver cells into the blood plasma and is excreted by the kidneys.
Where does urea diffuse?
From the liver to the kidneys
What is osmosis?
It is a special type of diffusion with water molecules
What does saturated mean?
No more solids to dissolve in the liquid
Water moves from an area of ___ concentration to and area of ___ concentration through semi-____ ____.
high
low
permeable membrane
When a cell is hypotonic what happens?
The cells explode as hypo means high. Hypotonic cells can burst.
When a cell is hypertonic what happens?
The cells will shrivel
What is plasmolysis?
When cells collapse in on themselves
When a cell is isotonic what happens?
Iso means the same meaning that everything stays the same.
What is the equation for finding out the percentage change in mass?
Change in mass divided by initial mass x 100
How can we find the change in mass?
Final mass- initial mass
Why is magnesium needed by a plant?
To make chlorophyll
What is active transport?
Moving molecules from an area of low concentration to high concentration.
How do minerals move from low concentration to high concentration in active transport?
In the roots, the transport protein in the semi-permeable membrane grabs the minerals and turns to drop them in the area of high concentration.
How does the transport protein move?
It uses energy from respiration to collect the minerals from the side of low to high concentration.
How do you calculate the surface area to volume ratio?
Surface area divided by volume
Smaller organisms have a ____ surface area to volume ratio.
higher
Larger organisms have a ____ surface area to volume ratio.
Smaller
What do alveoli do?
They increase surface area of the lungs.
What does the blue capillaries in the alveoli mean?
Deoxygenated blood with CO2.
What does the red capillaries in the alveoli mean?
Oxygenated blood carries O2.
What do we need for gas exchange?
good circulation
thin barriers to cross- quicker to diffuse
steep concentration gradient
short diffusion pathway
