B16.1 & B16.2 - Inheritance --> Chromosomes and genes & Cell division Flashcards
what are chromosomes made of?
dna
what do chromosomes contain?
genetic information in the form of genes
what are genes?
short length of DNA that codes for a protein
what is an allele
an alternative form of a gene
Whats a haploid nucleus?
nucleus containing a single set of chromosomes (23 chromosomes, not pairs)
what is a diploid nucleus?
nucleus containing 2 sets of chromosomes (46 chromosomes, 23 pairs)
what is mitosis?
nuclear division giving rise to genetically identical cells
what are the roles of mitosis?
-growth
-repair of damaged tissues
-replacement of cels
-asexual reproduction
What occurs before mitosis?
exact replication of chromosomes
what happens during mitosis?
copies of chromosomes separate, maintaining the chromosome number in each daughter cell
what is meiosis involved in the production?
gametes
what is meiosis?
reduction division in which the chromosome number is halved from diploid to haploid resulting in genetically different cells
give 3 examples of haploid cells
-sex cells
-red blood cells
-gametes
what cells are diploid cells?
body cells
what is a chromosome?
long length of DNA
where are genes found?
on chromosomes
what are 2 examples of alleles?
-eye colour
-hair colour
what are the 2 new cells formed during mitosis called?
daughter cells
what are parent cells and daughter cells to each other?
genetically identical
how many cells are producing as a result of mitosis?
2
type of cell division used for growth and repair is
mitosis
where is dna found?
in the nucleus
what are genes made of?
dna
why is dna essential for life?
it determines all of our features and cell activity
