Topic 1 - Key concepts in biology Flashcards
Name the 4 main sub-cellular structures of animal cells
nucleus, cell membrane, mitochondria, ribosomes
Name the 7 main sub-cellular structures of plant cells
nucleus, cell membrane, cell wall, chloroplasts, mitochondria, large vacuole, ribosomes
Name the 5 main sub-cellular structures of bacteria
chromosomal DNA, plasmid DNA, cell membrane, ribosomes, flagella
What are eukaryotic cells?
Cells with nuclei, including all animal and plant cells
What are prokaryotic cells?
Cells without nuclei, e.g. bacteria
How does the nucleus relate to its function?
It contains genetic material that controls the activities of the cell
What are the functions of the cell membrane?
It holds the cell together and controls what enters and leaves the cell
What is the function of mitochondria?
They are where most of the reactions for respiration take place
What is the function of ribosomes?
They are involved in the translation of genetic material in the synthesis of proteins
What is the cell wall made of?
Cellulose
What is the function of the cell wall?
It supports the cell and strengthens it
What do chloroplasts contain?
A green substance called chlorophyll
What is the function of chloroplasts?
They are where photosynthesis occurs
What does a large vacuole contain?
Cell sap (a weak solution of sugar and salts)
What is the function of the large vacuole?
It maintains the internal pressure to support the cell
What is chromosomal DNA?
One long circular chromosome in a bacterium that floats free in the cytoplasm (not in a nucleus)
What is the function of chromosomal DNA?
It controls the cell’s activities and replication
What is plasmid DNA?
Small loops (plasmids) of extra DNA that aren’t part of the chromosomal DNA (plasmids can be passed between bacteria)
What is the flagellum and what are its functions?
A long, hair-like structure that rotates to make the bacterium move.
It can be used to move bacteria away from harmful substances (e.g. toxins) and towards beneficial things (e.g. nutrients, oxygen).
In what 4 ways is a sperm cell adapted to its function?
1) Long tail to swim quickly to the egg
2) Lots of mitochondria to provide the energy needed to swim the distance
3) Acrosome at front of the head to store enzymes needed to digest through the membrane of the egg cell
4) Contains a haploid nucleus
In what 3 ways is an egg cell adapted to its function?
1) Contains nutrients in the cytoplasm to feed the embryo
2) Contains a haploid nucleus
3) Straight after fertilisation, its membrane changes structure to prevent any more sperm from entering, making sure the offspring have the right amount of DNA
In what way is a ciliated epithelial cell adapted to its function?
It has cilia (hair-like structures) on the top of it which beat to move unwanted substances (e.g. mucus) away
What is an epithelial cell?
A cell that lines the surface of an organ
