test Flashcards
Mitosis
Produces two daughter cells that are identical to the parent cell. This is the type of division involved in growth and repair of the body
Meiosis
Produces gametes (eggs and sperm) that have half the number of chromosomes of the parent cell
What are the six stages of mitosis
Interphase Prophase Metaphase Anaphase Telophase Cytokinesis
How many chromosomes in a body cell
46
What is the diploid number
The number of chromosomes in your body cells
What is the haploid number
The number of chromosomes in a gamete
Give five situations in which cell division in meiosis occurs
Growth Asexual reproduction Wound and tissue repair Tissues regeneration Research, tissue culture and tissue engineering
What are eukaryotic cells
Unicellular organisms with a nucleus
Interphase
Chromosomes replicate to have two chromatids
Prophase
Replicated chromosomes and their chromatids become visible
Metaphase
Chromosomes line up along the equator of the cell and a network of fibres appears extending from the poles of the cell to each chromosome.
Anaphase
The chromatids separate to become two independent chromosomes. The network of fibres contracts, pulling the chromosomes to opposite poles of the cell.
Telophase
Two nuclei form, each with the same number of chromosomes as the parent cell
A new nuclear membrane encloses the chromosomes at each pole. The chromosomes uncoil and are no longer visible as individual strands.
Cytokinesis
Division of the nucleus is complete. The cytoplasm then divides and the result is two identical daughter cells.
What are the stages of meiosis
Metaphase 1, anaphase 1, telophase 1, metaphase 2, anaphase 2, telophase 2
Metaphase 1
Replicated chromosomes form homologous pairs, attached to spindle fibres and lined up in the middle
Anaphase 1
One replicated chromosome of each pair moves to each pole
Telophase 1
Two cells are formed, each with one replicated chromosome
Metaphase 2
Chromosomes line up on the equator attached to spindle fibres
Anaphase 2
Chromatids separate and move to poles
Telophase 2
Four cells result with one copy of each chromosome, they are haploid gametes
RR
homozygous dominant
rr
Homozygous recessive
Rr
Heterozygous
Genotype
RR, Rr and rr represent the genotypes which are the actual genetic information carried by an individual
Phenotype
The red or white colour is the phenotype which are the observable characteristics or traits of the individual
What are sex linked genes
Found on the sex chromosomes and determine the sex
If colour blindness is a recessive allele, How would you represent a female who is heterozygous for for colour blindness and normal vision is dominant?
N n
X X
This female may not have colour blindness but she is a carrier.
Since colour blindness is an X linked genetic disorder, how would you represent a male who is colour blind
n
X Y
homozygous
When an individual has two of the same allele, whether dominant or recessive, they are homozygous.
heterozygous
When an individual has two different alleles, one dominant and one recessive.
plasmid
a genetic structure in a cell that can replicate independently of the chromosomes
