B2 - Cells, Tissues and Organs Flashcards
Give 2 functions of the nucleus.
- Controls the activities of the cell
* Carries genetic information as genes on chromosomes
What happens within the cytoplasm?
Chemical reactions
What is the cell wall made of?
Cellulose
What is the function of the mitochondria?
The mitochondria carry out respiration
What are bacteria?
Bacteria are single-celled organisms that are typically much smaller than plant or animal cells.
What is the definition of plasmids?
Extra loops of DNA
What are the two ways in which yeast cells are able to respire?
- Carry out aerobic respiration when there is plenty of oxygen
- Anaerobic respiration when there is no oxygen
What are specialised cells?
Cells that have adapted their structure to give them additional features that enable them to perform a certain function within the organism.
Give an example of a specialised cell.
• Sperm cells:
- A long tail to swim to the egg
- More mitochondria to provide energy
What is a tissue?
A tissue is a group of similar cells that work together for a specific function.
What is an organ?
An organ is formed from several tissues working together for a particular function.
What is an organ system?
A collection of organs that work together to perform an overall body function
What are the 3 main organs of a plant?
- Roots
- Stems
- Leaves
What is diffusion?
The net movement of particles from an area of high concentration to an area of low concentration.
What are the factors that affect the rate of diffusion?
- Temperature
- Diffusion distance
- Surface area
- Concentration gradient
What is the function of ribosomes?
They carry out protein synthesis.
In which part of the cell is energy released during respiration?
The mitochondria
What is cell differentiation?
When a cell becomes specialised due to cell growth.
What does muscular tissue do?
Contract to bring about movement.
What does glandular tissue do?
Glandular tissue produces substances e.g. enzymes, hormones
What does epithelial tissue do?
Epithelial tissue covers some parts of the body.
What does epidermal tissue do?
Epidermal tissue covers the plant.
What can mesophyll do?
Mesophyll can photosynthesise.
What can xylem and phloem do?
The can transport substances around the plant.
When you eat food, what must be changed?
Good must be changed from insoluble molecules, into soluble molecules (digestive system)
What does the digestive system consist of?
- GLANDS - pancreas, salivary glands which produce digestive juices
- STOMACH AND SMALL INTESTINE - where digestion occurs
- LIVER - produces bike
- SMALL INTESTINE - absorption of soluble food occurs
- LARGE INTESTINE - where water is absorbed from the undigested food, producing poo
What tissue does the stomach have?
- EPITHELIAL TISSUE - to line the inside of the stomach
- GLANDULAR TISSUE - to release digestive juices
- MUSCULAR TISSUE - to churn food and digestive juices
Give two reason why starch isn’t digested in the stomach.
- Doesn’t produce amylase
* Acidic pH destroys amylase made by the salivary glands
Give two differences between a plant leaf and yeast cell.
Leaf cells have chloroplasts and a cellulose cell wall, yeast cells do not.
When, and in which direction, will diffusion take place in solutions and in gases?
If two solutions are separated by a cell membrane:
• Particles will move from a region of high concentration to a region of low concentration.
• Gases will also defuse through the air from a region of high concentration to a region of low concentration.
