B2 Flashcards
What are the cell organelles in a plant cell?
- Nucleus
- Golgibody
- Ribosomes
- Cytoplasm
- Vacuole
- Cell membrane
- Mitochondria
- Cell wall
- Chloroplasts
What is diffusion?
Random movement of particles from a high concentration to a low concentration through a semi permeable cell membrane.
What increases the rate of diffusion?
- Bigger surface area (more diffusion, less time)
- More kinetic energy the particles have (move more and diffuse faster)
- A moist environment (stop diffusion membrane from drying out)
- Close to capillaries (shorter diffusion pathway)
What is equilibrium?
Equilibrium is achieved when all particles have been diffused are equally distributed throughout the cell
What are the three tissues in the stomach?
- Muscle
- Glandular
- Epithelial
What are tissues made of?
Same type of cells
What are muscles made of?
Different types of tissue
What is the muscle tissue?
- Specialised
- Has the ability to contract (to churn food, the muscle fibres get shorted when contracting)
- Made of muscle cells
- -They can move voluntarily and involuntarily
What is glandular tissue?
- Secretory cells
- Release hormones and digestive enzymes
- Tissue is rich in capillaries
- Each cell must contact a capillary directly to deliver hormones
What is epithelial tissue?
- Covers all surface of the body
- Closely packed, more than one layer
- Specialised to cover internal and external organs
What is the order of digestion?
- Mouth
- Oesophagus
- Stomach
- Small intestine
- Large intestine
- Rectum
- Anus
What happens in the mouth?
Teeth chew the food and the salivary glands release saliva containing amylase
What happens in the oesophagus?
Muscle walls contract to push food down. Process called peristalsis
What happens in the stomach?
- Food reaches the stomach and is churned by the walls contracting.
- Hydrochloric acid is released by the gastric pits in the walls.
- The acid contains pepsin which breaks down proteins.
- Pancreas produces the enzymes for intestine, as does the liver (bile)
What happens in the small intestine?
- Food is mixed with the pancreatic juices containing amylase, lipase and protease.
- Food molecules that are small enough to diffuse through the villi into the bloodstream.
What happens in the large intestine?
Absorption of juices and liquids back into the system
What happens in the rectum?
Fibre cant be absorbed so it is stored. Without fibre, digestion would not be effective
What happens in the anus?
Body waste is deposited
What do the xylem and phloem do?
- Xylem tissue carries the water around he plant
- Phloem tissue carries food and minerals around the plant
List specialised cells
- Palisade leaf cells
- Guard cells
- Red blood cells
- Sperm and egg cells
What is the mesophyll tissue?
The main part of a palisade cell where most of the photosynthesis occurs
What limits the rate of photosynthesis?
- Light intensity
- Carbon dioxide levels
- Temperature
How does light intensity effect the rate of photosynthesis?
Not enough light=little photosynthesis
Too much light=enzymes may become denurtured.
Not enough of other products
How do carbon levels effect the rate of photosynthesis?
- Not enough for photosynthesis to happen
- If there’s alot of carbon dioxide but photosynthesis stops, there must be another limiting factor
How does temperature effect the rate of photosynthesis?
-If the temperature is too high, the enzymes become denurtured.
How do plants use glucose?
- Respiration
- Cellulose
- Making proteins
- Stored in seeds
- Stored as starch
- In fruits
How is glucose used for respiration?
- Used for respiration
- Releases energy which enables them to convert the rest of the glucose into other substances, so they can build new calls and grow
How is glucose used for making cell walls?
- Glucose is converted into cellulose for making strong cell walls, especially in a rapidly growing plant
- Acts as pressure vessel to stop over expansion by water
How is glucose used for making proteins?
- Glucose is combined into nitrate ions (absorbed from the soil) to make amino acids, which are then made into proteins.
- Proteinsynthesis
How is glucose stored in seeds?
- Glucose is turned into lipids (fats & oils) for strong storing in seeds.
- Sunflower seeds, for example, contain a lot of oil- we get cooking oil and margarine from them.
- Seeds also store starch
How is glucose stored as starch?
- Glucose is turned into starch and stored in roots, stems and leaves. For when photosynthesis isn’t happening (winter)
- Starch is insoluble which makes it much better for storing than glucose
How is glucose used in fruits?
- Glucose and fructose stored in fruits
- Causes sweet taste, so animals eat them, causing seeds to spread through their poo
What do we need to survive?
- Water
- Food/nutrients
- Temperature
- Oxygen
- Carbon dioxide (plants)
Describe a quadrat
- Used to investigate distribution of plants or slow moving animals
- 1m squared of wood, plastic or metal square
- Placed at random places between two points (eg shore and woods)
- Count how many things are inside the quadrat
- Find the average to calculate the distribution of the plant per metre squared
Describe a transect
- More commonly used
- A tape is placed between two points
- The quadrat is placed along the tape at regular 1m intervals
- Results represented in a table, average, mode and range calculated
- Can also measure physical factors such as light levels and soil pH, things that may effect the distribution along the transect
- Appropriate situations for use include uneven or unexpected distribution of plants due to a suggested physical factor
- Don’t always require a quadrat.
