Dna Fact Sheet

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Reproduction
Fact Sheet

Male: Sperm
Female: Ovum (egg)

What happens to Gametes at Fertilisation?
Fertilisation is the process where sperm (from the male) and the ovum (from the female) fuse together to form the zygote. Each gamete contains 23 chromosomes which combine together, in the zygote, to combine to a full set of 46 chromosomes – half from the father and half from the mother.. Summed up, it is where the male gamete and a female gamete join. The fusion of gametes enables the genetic information to mix.

Proteins found in the Human Body
Enzymes – they are proteins which catalyse chemical reactions. They contain a lock-and-key mechanism which makes them highly specific to certain substrates. Each enzyme accelerates only one or two chemical reactions – i.e. amylase. Collagen- a protein that is found in the tendons.

Keratin – a fibrous structural protein that is key in the make-up of hair and nails. Elastin– a protein that connects body tissues (enables them to contract and relax).

Plants can continue to grow because their cell division is an active process, in the sense of unspecialised stem cells. The process of cell division is carried out by meristems. Meristems can are undifferentiated cells that continuously divide if a part of plant requires repair or growth. Meristems last during the plant’s entire life. The reason why humans cannot repair large parts of their bodies is because they contain only a few stem cells that can specialise into a few cell-types (adult stem cells).

Gametes/Sex Cells in Plants
The male sex cell is the sperm which is found in the pollen grains. The female sex cell is the ovary. The ovary is located in the stigma.

The scientific name for the fertilised egg is a zygote. A zygote contains a full set of chromosomes (46) – half from each parent.

The scientific name for unspecialised cells which make up the fertilised egg and the embryo are called Embryonic Stem Cells.

Process of making gametes in...
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