DNA Structure
What is the name of the building blocks of DNA strands?
Nucleotides
Why does DNA replicate?
Growth, repair, reproduction
What type of cells are created in mitosis?
Regular body cells
How many chromosomes end up in the cells created by meiosis?
23
What letter represents a dominant trait?
Capital
What makes up the 'backbone' of DNA strands?
Phosphate and Sugar
What are the names of the two proteins involved in replication?
Helicase and polymerase
How many cells are created in mitosis, and are they identical?
2 identical cells
How many cells are created in meiosis, and how are the two major stages labelled?
4, Meiosis I and II
What is the difference between a genotype and a phenotype?
Genotype = alleles (letters)
Phenotype = physical trait
What the complementary strand for:
TTA CAG TCC ACT
AAT GTC AGG TGA
What is the role of helicase?
Unzips DNA strands
What are the 6 stages of mitosis?
Interphase, prophase, metaphase, anaphase, telophase, cytokinesis
How many lines of chromosomes are made in Metaphase I and II?
2 lines in Metaphase I, 1 line in Metaphase II
What is another word for a hybrid?
Heterozygous
How does the number of chromosomes differ between human cells and between different animal species
23 individual vs pairs of DNA
Different numbers of chromosomes in different species
Where does the new DNA strand come from?
Polymerase brings free-floating complementary bases to the existing DNA strand.
What happens during the anaphase stage of mitosis?
Chromosomes are split apart and brought to different sides by the spindle fibres
What distinguishes Prophase I and II?
Prophase I - DNA condenses
Prophase II - no major events
If two heterozygous parents are crossed, what percentage of offspring are likely to have the recessive trait?
Place in order of size (smallest to largest):
Chromosomes, DNA strands, genes
DNA strands, genes, chromosomes
Why is this process known as 'semi-conservative'?
What is one factor that distinguishes mitosis from meiosis?
Any of:
- 2 cells
- Identical cells
- PMAT x1
- Full set of DNA
- No swapping of DNA
What is one factor that distinguishes meiosis from mitois?
Any of:
- 4 cells
- Non-identical cells
- PMAT x2
- Half set of DNA
- Swapping of DNA
Is it possible for two parents with the dominant trait to have offspring with the recessive trait? Why/why not?
Yes - if both parents are heterozygous