Genetics & Inheritance Flashcards
Define the term allele
an alternative version of a gene
define homozygous allele
identical alleles for a gene
define heterozygous allele
different alleles for a gene
name the two types of cell division
Somatic & Reproductive
(mitosis & meiosis)
state the end products of Somatic (mitosis) division
2 Identical cells which each have 46 chromosomes (23 pairs)
state the end product of reproductive (meiosis) division
4 unique daughter cells each with 23 single chromosomes
Where does somatic division typically occur?
body tissue/cells.
-typically used to repair damage in body tissue.
-Asexual reproduction.
where does reproductive division typically occur?
occurs in the testes and ovaries.
How does genetic variation occur?
The process of crossing over
What is crossing over?
Where chromosomes swap information (allele) to ensure genetic variation
define cancer
uncontrolled proliferation of cells
define the terms malignant & benign
•malignant can spread (metastasis)
•benign do not spread.
Name the four types of cancer
Carcinoma,
Melanoma,
Lymphoma,
Leukaemia.
For each type of cancer, state the tissue it arises from
Carcinoma: Epithelial
Melanoma: Melanocytes
Lymphoma: Lymphatics
Leukaemia: Leukocytes
State the three causes of cancer
Environmental,
Viral,
Genetic.
define inheritance
The passing of traits from one generation to another.
define genetics
the composition of an individuals genotype & phenotype.
define genotype
the genetic makeup of an individual (what genes they have)
define phenotype
the physical characteristics of a gene (brown hair, blue eyes)
define mutation
a permanent, irreversible change to DNA
define autosome
the first 22 chromosomes
define x-linked
the 23rd chromosomes
What is a dominant gene?
a gene which will ALWAYS appear as it masks the recessive gene (RR)
what is a recessive gene
a gene that will typically be masked by a dominant gene, unless only recessive genes are present. (rr)
