nucleus dna-chromosomes

1. To what extent can our genetics determine what we
can be in life?

2. DNA: Chromatin, chromosomes

5.  Molecules that contain the all the genetic information of the
individual.
 Depending on how packed the DNA is we talk about:
Chromatin: DNA molecules are more spread out in the nucleoplasm. DNA
is normally in this state.
Chromosomes: DNA molecules are highly coiled and packed forming
specific structures. DNA only coils into chromosomes when the cell is going
to divide.
 The DNA molecules are made up of a sequence of bases which form
codes.
 These codes are the intructions for the formation of proteins.
Proteins are responsable for carrying out all metabolic processes.
 Each complete code that codifies for a protein is called a gene.

7.  When the DNA packs the resulting chromosome has 2
sister chromatids.
 Sister chromatids: identical copies of a DNA molecule.
 Each chromatid has 2 arms (p and q)

9.  All human somatic cells have 46 chromosomes (23 pairs) or 2 sets
(2n)
 Diploid cells (2n): cells with pairs of chromosomes.
 The pair is made up by Homologous chromosomes.
 Chromosomes that carry the same genes, but not necessarily the same
genetic information.
 They have the same shape and structure, and banding.
 Human gamets have 23 chromosomes in total. Only one set of
chromosomes (n).
 Haploid cells(n): cells with only one chromosome of each type

10.  Each specie has a specific number of different
chromosomes (n)
 Their somatic cells have pairs of chromosomes 2n
 Their gametes have only one set of chromosomes (n)
Calculate the haploid number (n)
for each species:(2n)
Worksheet

11.  Carry same genes in the same locus, but with different (or not)
information for each of the genes.
 Somatic cells (diploid cells) carry 2 pieces of information for
each gene. 2 chromosomes of each type.
 One inherited from the mother and the other from the father.

12.  Chromosomes have the peculiar property of staining in bands, or
chromosome segments, allowing the precise identification of individual
chromosomes or parts of chromosomes.
Definition from: MeSH via Unified Medical Language System at the National Library of Medicine
 The chromosomes are visualized as consisting of a continuous series of
bright and dark bands.
 These bands are always the same in each chromosome, because the
position of the genes and therefore bases in the DNA is always the same.
 The specific position of a gene is called the gene locus.

14.  Organized positioning of
chromosomes extracted
from a cell.
 by size, structure and
centromere position, and
bands
 Gives information on the
number of chromosomes of
an organism.

15. Human karyotype: (somatic
cell)
 Shows 23 pairs of
chromosomes in total
 22 pairs of autosomes and 1
pair of sex chromosomes.
 Sex chromosome pair can
be:
 XX : in females
 XY: in males

16. 1. Is it genetic material of a diploid or haploid cell?
2. Is it genetic material of a uman or non human cell?
3. Is it genetic material of a male or female individual?

17. 1. Is it genetic material of a diploid or haploid cell?
2. Is it genetic material of a human or non human cell?
3. Is it genetic material of a male or female individual?