Inheritance 1 and 2 Flashcards
What does each duplicated chromosome consist of
Two identical chromosomes which are called Sister chromatids
What are sister chromatids are held together by
Centromere
How many chromosomes does a human cell contain
46, which form 23 pairs
What is a male sex chromosome
One x and one y
What is a female sex chromosome
2 x
Of the 46 chromosomes, how many are inherited from your parents
One of each pair (23) from your mum and the other 23 from your dad
What is DNA
A large molecule that contains genetic information
It is made up of a double helix structure made of two strands
What is the backbone of DNA made of
Alternating sugar (deoxyribose) and phosphate
What does the middle of DNA consist of
Bases-there are four Adrenaline (A) Thymine (t) Guanine (g) Cytosine (c)
What is a nucleotide
A unit of phosphate, sugar and a base
How did the bases always pair?
A always pairs with T
C always pairs with G
What is a gene
A small section of DNA/a chromosome that contains information for making protein
Each three bases contains the code for what
An amino acid
How many genes does eat chromosomes contain
Thousands
What are the proteins responsible for
Certain characteristics such as eyecolour
What is the first step of a cell dividing
- DNA double helix gets unwound
- And the two strands separate
What happens after the double helix has unwound when the cell is dividing
New DNA strands are made up by connecting free nucleotides together using the old strand as a template
The newly formed DNA double stands rewind into a double helix
What is the result of DNA replication
Newly Formed DNA molecules contain:
-one strand of the original DNA
-One new strand
This is called semiconservative replication
What is mitosis
The process of cell division
What is the order of mitosis
- Interphase
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
What happens during interphase
- DNA is copied i.e. chromosomes are duplicated
- Chromosomes are not visible
What happens during prophase
- Chromosomes condense and become visible
- It’s chromosome consists of 2 chromatids
What happens during prometaphase
- The nuclear membrane disappears
- Spindle fibres are formed
What happens during metaphase
Spindle fibres align the chromosomes in the middle of the cell
What happens during anaphase
-Spindle fibres pull the chromatids apart to opposite ends of the cell
What happens during telophase
-A new nuclear membrane forms around each of the two sets of chromosomes
What happens during cytokinesis
-The cell starts to divide into two cells