Inheritance II Flashcards
Gene
= a small region of the DNA (a small part of a chromosome) that counts informations fro making a protein
1 amino acid is made up of …
3 bases
Protein
= chain of amino acids
DNA code?
= the rule (code) by which the information encoded in DNA sequence is translated into an amino acid sequence
Humans have … chromosomes
22 pairs of somatic chromosomes
1 pair of sex chromosomes
Each pair of somatic chromosomes consists of …
One chromosome from the father and one from the mother,
The chromosomes in each pair are called …
Homologous chromosomes, because they contain the same genes
Result of mitosis:
Production of 2 geneticalley identical cells (=clones)
When is mitosis important?
- to grow more cells (during growth)
- to replace cells (repair)
Genetic variation
= genes inherited from parents
Environmental variation
= differences caused by the environment
Each homologous chromosome has the …
Same type of gene
But chromosomes form father and mother may …
Have different version of genes (=alleles)
Some alleles are…
Dominant over other alleles
Allele
= A version of a gene
Dominant Gene
= Only one copy is necessary for characteristics to be shown
Recessive allele
= 2 recessive alleles are needed (no dominant allele are present) for characteristics to be shown
Genotype
= the genetic make-up, i.e. which alleles are present
Homozygous
= have 2 identical alleles
Heterozygous
= have 2 different alleles
Phenotype
= both alleles contribute to the phenotype, so that both characteristics are present at the same time
Co-dominance
= both alleles contribute to the phenotype so that both characteristics aren’t present
Punnett squares
= a diagram showing genetic cross
Meiosis
= special type of cell division by which gametes (sex cells) are made
Diploid
= 2 sets of chromosomes
Haploid
= 1 set of chromosomes
Result of meiosis:
- four genetically different haploid cells (with only 23 chromosomes)
- meiosis leads to great variation with gametes
What is the purpose of mitosis ?
To make more cells for growth and repair
What is the purpose of meiosis?
To make gametes
Where dies mitosis take place?
In the whole body
Where does meiosis take place?
Ovaries in woman and testis in man
How many rounds of cell division are there in mitosis?
1
How many rounds of cell division are there in meiosis?
2
How many cells are produced in mitosis?
2
How many cells are produced in meiosis?
4
What happened to the chromosome number in mitosis?
It remains the same
What happens to the chromosome number in meiosis?
It halves
Are the parent and daughter cells genetically identical in mitosis?
Yes
Are the parent and daughter cells identical in meiosis?
No
Are all daughter cells identical in mitosis?
Yes
Are all daughter cells in meiosis identical?
No
Pedigree Tree
= A family tree that records and traces the occurrences if a characteristic in a family
Variation
= small difference between, members of the same species
