B2.1 Flashcards
What are the main structures in an animal cell and what are their functions?
Nucleus- contains DNA and controls activities of the cell
Cell membrane- controls passage of substances
Cytoplasm- jelly like substance that chemical reactions take place in
Mitochondria- release and uses energy from respiration
Ribosomes- where protein synthesis takes place
What do plant cells have that animal cells don’t?
Cellulose cell wall- keeps the structure of cell and keeps it together
Chloroplast- contains chlorophyll which absorbs light energy to make its own food via photosynthesis
Vacuole- sac that contains cell sap which keeps the cell rigid to support the plant
What happens when you culture bacteria on an agar plate?
You grow many millions of bacteria.
What are the 3 structures in a bacteria cell that isn’t in a plant/animal cell?
Plasmids
Slime capsule
Genetic material
How do yeast cells reproduce and why are they specialised?
Reproduce by asexual budding.
Specialised to be able to survive for longer when there isn’t a lot of oxygen.
When yeast cells use oxygen for aerobic respiration, what does it break down?
Oxygen breaks down the sugar to provide energy for the cell.
During aerobic respiration in yeast cells, what do they produce?
Water and carbon dioxide.
What is respiration of yeast called?
Fermentation.
Why are some cells specialised?
In order to carry out particular jobs.
What happens to a cell when it becomes specialised?
It’s structure is adapted to suit the particular job it does.
Root hair cells:
Advantage of root hair cells?
What does the xylem tissue do?
Helps them to take up water more efficiently.
Xylem tissue carries water and mineral ions to the plant.
Two main adaptations of root hair cells:
- increase the surface area for water to move into the cell
- large permanent vacuole that speeds up the movement of water by osmosis
Sperm cells:
Advantage of a sperm cell?
What does it have to do?
They contain genetic information of the male.
Has to move through water then break into the egg.
What are the main functions of a sperm cell?
- long tail helps to move
- full of mitochondria which provides energy for the tail to work
- acrosome stores digestive enzymes for breaking down the outer layers of the egg
- ledge nucleus which contains genetic information
Cone cells:
Advantage of a cone cell?
Where is it placed?
They make it possible to see in colour.
In the light-sensitive layer of the eye (retina).
Main functions of a cone cell:
- outer segment contains a special chemical which changes chemically in coloured light
- mitochondria which releases energy to reform the visual pigment
- specialised synapse that connects to the optic nerve which triggers when visual pigment changes
What is diffusion?
Particles of a gas spreading out which results in the net movement of particles.
What is a net movement in diffusion?
Particles moving from a high concentration to a low concentration.
When will diffusion take place quickly?
When there is a big difference in concentration between two areas.
What is the equation for net movement?
net movement=particles moving in-particles moving out
What is the difference between two areas of concentration called?
Concentration gradient.
What effects the rate of diffusion?
Temperature
Concentration gradient
How does the temperature effect the rate of diffusion?
Increase in temperature means the particles in a gas or a solution move quicker.
This increases the rate of diffusion.
What is a tissue?
What is an organ?
Group of cells with similar structure and function working together.
Organs are made up of tissues which work together.
Give 3 animal/human tissues and their function:
Muscular tissue-contracts to bring about movement
Glandular tissue-contains cells that can produce substances such as enzymes and hormones
Epithelial tissue-covers outside of the body as well as internal organs
Give 3 plant tissues and their functions:
Epidermal tissue-covers the surfaces and protect them
Mesophyll tissue-contains lots of chloroplast and can carry out photosynthesis
Xylem and phloem tissue-transports water and dissolved minerals and food
What are organs made up of? Give an example
Made up of tissues which all work together.
Stomach digests the food.
Functions of the 3 tissues in a stomach:
Muscular tissue-churns the food and digestive juices
Glandular tissue-produces digestive juices that break down food
Epithelial tissue-covers the inside and outside of the organ
What is an organ system?
What do they do?
Organs working together.
Transport blood or digest food.
What is the function of the digestive system?
Exchanges food substances with the environment.
What is made up of insoluble molecules?
Foods that we take in and eat.
Why do the insoluble molecules have to be broken down and what does it form?
The body cannot absorb and use the molecules.
They are broken down into smaller, soluble molecules.
What are the two main organs where food is digested?
Stomach and small intestine.
What are the 3 main organs in a plant and their function?
Roots-take up water and minerals from soil
Stem-supports leaves and flowers
Leaf-carries out photosynthesis
