dna & genes Flashcards
(22 cards)
What does DNA stand for?
Deoxyribonucleic Acid
What is the primary function of DNA?
Contains instructions for making proteins
How does DNA influence an organism?
Determines traits like eye colour and blood type
What shape does DNA have?
Double helix
What is a gene?
A small section of DNA that codes for a specific protein
What are chromosomes made of?
DNA and protein
Where are chromosomes located?
In the nucleus
What is meiosis?
Special cell division that produces haploid gametes
What is fertilisation?
The fusion of male and female gametes to form a zygote
What is the chromosome number in a zygote?
Diploid (full set of chromosomes)
Define dominant allele
Always shows in the phenotype if present
Define recessive allele
Only shows if both alleles are recessive
What are the possible offspring genotypes for Bb x Bb?
BB, Bb, bb
What is the phenotypic ratio for brown and blue eyes from a Bb x Bb cross?
75% Brown eyes, 25% Blue eyes
What is a Punnett square used for?
Predicting ratios of offspring
Fill in the blank: A mutation is a _______ change in the DNA sequence.
permanent
What are spontaneous mutations caused by?
Errors during DNA replication
Name an environmental factor that can cause mutations.
Radiation, chemicals, or viruses
What can mutations be classified as?
Beneficial, harmful, or neutral
True or False: Colour blindness is more common in females than in males.
False
What is the genotypic ratio from a monohybrid cross?
1 BB : 2 Bb : 1 bb
What is the phenotypic ratio from a monohybrid cross?
3 Brown Eyes : 1 Blue Eyes
