Flashcards in B2.1 Cells, Tissues And Organs Deck (48):
What's the function of a nucleus?
Controls all activities of the cell. Contains genes of the chromosomes
What's the function of a cell membrane?
Controls the passage of substances into and out of the cell.
What are ribosomes?
Where protein photosynthesis takes place
In both animal and plant cells
What are mitochondria?
Structures in the cytoplasm in both animal and plant cells.
Where oxygen is used and most of the energy is released during respiration
What's the cell wall?
Made of cellulose
Strengthens the cell and gives it support
What are chloroplasts ?
Found in all green plants of a plant and they contain chlorophyll
Make food by photosynthesis
What's the vacuole?
Space in the cytoplasm of a plant cell filled with cell sap. Supports the plant
What are three features that are in a plant cell but not an animal cell?
What's the equation of aerobic respiration?
Glucose + oxygen -> carbon dioxide + water +energy
What's the equation for anaerobic respiration in plants?
Glucose -> ethanol + CO2 + little energy
What are the features in a yeast cell?
(Same as animal cell but has a cell wall)
What features are there in a bacteria cell?
Genetic material - NO NUCLEUS
Name three types of microorganism
How can bacteria be useful?
Used in medicine and foods eg. Yoghurt
Why is yeast useful?
Used in foods like bread an drinks like alcohol
How does yeast reproduce?
Splits into two identical copies
A genetic structure in a cell that can replicate independently of the chromosomes
The chemical breakdown of a substance by bacteria, yeasts or other micro organisms
What is the job of a root hair cell?
To collect water and nutrients for a plant to help it
What are the specialised features of a root hair cell?
Long and wavy to collect as many nutrients as possible
Large surface area
What are the features and functions of a fat cell?
Features - mitochondria, little cytoplasm, expands 1000x itself
Function - stores energy
What are the features and functions of neurones?
Features - long and thin, can carry electrical impulses
Function - carry information from the brain to rest of body
What are the features and functions of palisade cells?
Large surface area
Many tightly packed chloroplasts
Where photosynthesis happens to produce food
What are the features and functions of red blood cells?
Features - large surface area, small diameter, no nucleus
Functions - to carry oxygen around the body
What are the features and functions of sperm cells?
Features - large nucleus, contain digestive enzymes, many mitochondria
Functions - carries half the info to fertilise an egg with
What are the features and functions of guard cells?
Features - half circle shape, found in pairs, they close when they're full of water
Function - they allow oxygen into a plant and let CO2 out
What happens in cytoplasm?
Chemical reactions which are controlled by enzymes
What is diffusion?
Where a net of particles spreads from a high concentration to a low concentration. This happens in gases or liquids.
What happens to diffusion as temperature increases?
Particles move quickly so therefore rate of diffusion increases
The greater the difference in __________ the _________ the rate of diffusion. This difference between two areas of concentration is called the concentration ________.
Where does diffusion happen in the body?
The lungs - cell membrane is thin and large SA so oxygen can diffuse in and carbon dioxide can diffuse out
Small intestine - lots of villi that push the nutrients along the intestine, large SA and thin membrane
Placenta - thin membrane so nutrients can diffuse to foetus easily, good blood supply.
Where does diffusion take place in the plant?
The leaf - thin cell membrane so oxygen and carbon dioxide can diffuse. Guard cells open and close
What's a tissue and give an example.
Group of specialised cells all carrying out the same function
Muscular tissue, glandular tissue, mesophyll tissue
What's an organ and give an example.
Made up of tissues, several tissues working together
Stomach, kidneys, brain, heart etc.
Describe the digestive system.
The food you eat is made up of large insoluble molecules and they need to be broken down. Through your mouth, gullet, diaphragm, stomach, liver, gall bladder, bile duct, pancreas, small and large intestine, appendix and rectum, enzymes break down these large molecules so your body can absorb the useful nutrients.
Name the plant organs and their functions
Leaves - collects nutrients and carries out photosynthesis
Stem - supports the plant and makes it stand up right
Roots - collects water and nutrients from the ground but also supports the plant
How are plant cells adapted to diffusion?
The concentration of CO2 is greater outside the cell than inside so co2 diffuses into the cell. Vice versa with oxygen. The cell membrane is thin so the gases can diffuse. The cells are wide with a spongy layer inside to provide a large surface area to collect the gases.
How are tissues adapted?
Alveoli to make sure the gases sufficiently pass through
How are organs adapted?
Large surface area
Extensive capillary network to exchange gases and diffusion can happen quicker
Why is diffusion important?
Means gases and substances can flow to all parts of your body and the environment
LEARN CROSS SECTION OF A LEAF
LEARN LEARN LEARN
GO GO GO
What's the equation for anaerobic respiration in animal cells?
Glucose -> lactic acid + energy
What does a waxy cuticle do?
Reduces water loss
What does the epidermis do?
No chloroplasts so allows light to penetrate
What do stomata and guard cells do?
Allows carbon dioxide and oxygen out
Controls water loss
What does the palisade (mesophyll) do?
Many chloroplasts to trap light
Near top of leaf for receiving more light
What does the spongy mesophyll do?
Air spaces for rapid movement of gases