For my independent year 12s To do on

For my independent year 12’s!!! To do on Friday

Native black Robin �Why allele frequencies are important! �http: //tvnz. co. nz/meet-the-locals/meet-locals-2008 episode-152 -video-2320248

Watch this - mutations �http: //www. youtube. com/watch? v=efstlgoynlk

Meiosis �Process of cell division that occurs in sex organs (ovaries and testes) and produce the sex cells (gametes)

Meiosis �Process of cell division that occurs in sex organs (ovaries and testes) and produce the sex cells (gametes) �In many species, each somatic cell (general body cell) has pairs of chromosomes. This is known as the diploid number and is depicted as 2 n.

Meiosis �Process of cell division that occurs in sex organs (ovaries and testes) and produce the sex cells (gametes) �In many species, each somatic cell (general body cell) has pairs of chromosomes. This is known as the diploid number and is depicted as 2 n. �(humans have 23 pairs of chromosomes to give 46 – our diploid number)

Meiosis �Pairs of chromosomes are known as homologous – they are identical in length and shape and have the same genes at the same location (locus)

Meiosis �Pairs of chromosomes are known as homologous – they are identical in length and shape and have the same genes at the same location (locus) �The alleles of these genes can be different (eg A or a) because one comes from mum and one from dad.

Meiosis �Pairs of chromosomes are known as homologous – they are identical in length and shape and have the same genes at the same location (locus) �The alleles of these genes can be different (eg A or a) because one comes from mum and one from dad. �The gametes produced in meiosis have half the diploid number of chromosomes (one from each pair) – this is known as the haploid number, ‘n’ **I remember it by diploid = double, haploid = half**

Meiosis �Pairs of chromosomes are known as homologous – they are identical in length and shape and have the same genes at the same location (locus) �The alleles of these genes can be different (eg A or a) because one comes from mum and one from dad. �The gametes produced in meiosis have half the diploid number of chromosomes (one from each pair) – this is known as the haploid number, ‘n’ **I remember it by diploid = double, haploid = half** �So the haploid number in humans is 23.

Meiosis �When the egg and sperm fuse in fertilisation, the diploid number of chromosomes is restored in the zygote (the fertilised egg).

Meiosis �When the egg and sperm fuse in fertilisation, the diploid number of chromosomes is restored in the zygote (the fertilised egg). �From then on, the mitotic divisions (remember… dividing identically) maintain the diploid number.

Watch these �http: //www. youtube. com/watch? v=D 1_-m. QS_FZ 0 �http: //www. youtube. com/watch? v=k. VMb 4 Js 99 t. A