DNA
What does Cytosine pair with?
Guanine
Name 2 factors that can affect enzyme activity.
Temperature and pH
What is cell division?
The process where a single cell can produce two identical cells during mitosis (cell division).
The function of the bladder.
To store urine.
Definition of a phenotype.
The physical appearance of an individuals genotype.
Whats the function of an enzyme?
Speeds up chemical reactions in a cell without being used up itself.
Explain what happens if an enzyme becomes denatured.
The activity of the enzyme will stop as their active site has changed shape.
Whats the function of spindle fibres.
During cell division the spindle fibres attach to each pair of chromatids, shortening to pull the chromatids apart.
Where does the zygote implant and grow?
Uterus
The definition of homozygous.
An individual who has inherited the same allele for a gene.
What shape is DNA?
A double stranded helix.
What 4 things do enzyme reactions require
Active site
Substrate
Products
Enzyme
Why are there ethical issues surrounding the use of embryonic stem cells.
It involves the destruction of the embryo.
What is formed during fertilisation.
Zygote
Give 2 examples of continuous variation.
Height
Weight
Hand span
How many pairs of chromosomes do humans have?
23
Describe a synthesis reaction.
A type of enzyme reaction that results in the build up of smaller molecules into larger molecules.
What 2 places do stem cells come from?
Bone marrow and Embryos
Describe the function of the petals.
To attract insects for pollination.
Define discrete variation.
Characteristics controlled by a single gene.
How are DNA strands held together?
By complementary base pairs.
Describe a degradation reaction.
An enzyme reaction that results in the breakdown of bigger molecules into smaller molecules.
List 3 controversial biological procedures.
Pharming, Genetically modified organisms and Gene therapy.
Describe the process of fertilisation in plants.
Pollen is produced in the anthers. It can be distributed by wind or pollinators to fertilise the ovule which then develops into a seed and the ovary develops into a fruit to protect the seed.
Explain inheritance
Humans inherit half of their DNA from their mother and half of their DNA from their father.