Unit 1 Flashcards
What are eukaryotes?
Cells which have a membrane bound nucleus which stores genetic material.
What are the cells of eukaryotes?
Animals, plants, and fungi.
What are prokaryotes? Give examples of what they do/don’t have.
Cells which do not have membrane bound organelles.
They do not have mitochondria or the nucleus.
What cells are prokaryotes?
Bacteria.
Structures which both the eukaryotes and prokaryotes have?
Cell membrane, cytoplasm, cell wall.
What are codons?
The series of base triplets which make up RNA.
What are nucleotides consisted of?
A base, a deoxyribose sugar, and a phosphate group.
Give full names of A, T, C, and G.
Adenine, thymine, cytosine, and guanine.
What holds the nucleotides together?
Strong chemical bonds.
State the numbers on the dna strand, starting with the top left, then top right, bottom left, then bottom right.
5’, 3’, 3’, 5’.
What is meant by anti-parallel?
When two strands are side by side, but are going in opposite directions.
What is PCR? What does it stand for?
Polymerase chain reaction.
What is PCR? Give def.
PCR is the method to make multiple copies of a target DNA sequence.
What is required to carry out PCR?
Buffer, template DNA, primers, nucleotides, DNA polymerase.
What’s the use of PCR? What can/does it do?
Can be used to diagnose early malignant diseases, like leukaemia or aids.
Give the steps of PCR.
- DNA molecule is denatured, which will break hydrogen bonds.
- DNA is left to cool, primers bind themselves to target strands.
- DNA is then reheated, so primers can extend.
What is gene expression? Give def.
Gene expression is when specific genes are activated to produce a required protein.
What processes make up gene expression?
Transcription and translation of DNA sequences.
What is transcription?
The first step in protein synthesis.
Where does transcription start and end?
Starts at the promoter, ends at the terminator.
What are introns?
Non-coding regions.
What are exons?
Coding regions.
What types of RNA are involved with gene expression?
mRNA, tRNA, rRNA
What enzyme is required during transcription?
RNA polymerase.
Where does transcription occur?
In the nucleus.
What is cellular differentiation? Give def.
Differentiation is the process in which unspecialised cells become specialised to perform a specific function.
What happens during differentiation? Give steps.
- Many essential genes remain switched on.
- Some genes for specific characteristics are switched on.
- Unnecessary genes are switched off.
Give examples of differentiation.
Sperm: have tails to allow them to swim.
Red blood cells: have increased surface area to be able to carry more oxygen.
What is the cost of differentiation? What does this mean?
Cells which are specialised often cannot make copies of themselves. This results the storage of stem cells so the body can replenish these cells whenever needed.
What are meristems?
Meristems are regions of unspecialised cells in plants, which are capable of cell division (growth). These unspecialised cells also have the ability to become any specialised cell.
what process is responsible for growth in plant cells?
Mitosis, elongation, division.
Where are meristems?
At the tip of the roots and shoots.
What are stem cells?
Cells which can constantly undergo cell division, and can become any cell.
What are the two types of stem cells?
- Embryonic stem cells (found in embryos)
- Adult (tissue) stem cells (found in children and adults)
What do embryonic stem cells do?
They can differentiate into all cell types and make up an organism, important for growth.