Genetics Flashcards
What is a gene?
A gene is a section of chromosomes.
What are genes made of?
Genes are made of a chemical called DNA
What type of alleles are always show?
Dominant (E.g - brown eyes, B)
What are living things made up of?
Building blocks called cells
How many chromosomes do human cells have in their nucleus?
46
In how many numbers of pairs are the chromosomes found?
23 pairs (One from mam and one from dad)
What pair is special and why?
Cell 23, it’s the sex chromosome and determines the gender.
What are the sex chromosome for a male and female?
Male - XY
Female - XX
What is a genotype?
The type of genes - shown with two letters. (E.g - Bb)
What is a phenotype?
The physical characteristic shown as a result of the genotype. (A physical feature)
What is an allele?
Different versions of the same gene.
What is a homozygous?
When the two genes in the genotype are the same. (E.g - BB)
What is a recessive allele?
With this allele, you must have two copies of it for the characteristic to be shown.
What cell structure are chromosomes found in?
The nucleus.
What shape is DNA?
A double helix.
Define heterozygous.
Where the two genes in a genotype are different (E.g - Bb)
