MITOSIS & ASEXUAL REPRODUCTION

QUICK RE-CAP FROM LAST LESSONa) Why alleles exist in pairsb) What causes new allelesc) What causes the differences between the

alleles of a gened) The importance of alleles

e) (I will draw some sections of DNA on the board, use the diagram to answer this last question)

f) Why the DNA is from the same geneg) Why the DNA is from two different alleles

MITOSIS & ASEXUAL REPRODUCTION The body makes new cells for growth, repair

and replacement of old cells.

MITOSIS & ASEXUAL REPRODUCTION The body makes new cells for growth, repair

and replacement of old cells. Each new body cell formed needs a complete

set of chromosomes to develop, function and carry out essential life processes.

MITOSIS & ASEXUAL REPRODUCTION The body makes new cells for growth, repair

and replacement of old cells. Each new body cell formed needs a complete

set of chromosomes to develop, function and carry out essential life processes.

In humans, each body cell needs 46 chromosomes/23 pairs.

MITOSIS & ASEXUAL REPRODUCTION The body makes new cells for growth, repair

and replacement of old cells. Each new body cell formed needs a complete

set of chromosomes to develop, function and carry out essential life processes.

In humans, each body cell needs 46 chromosomes/23 pairs.

Mitosis is the type of cell division that produces new body cells.

MITOSIS Prior to mitosis, chromosomes and their DNA

replicate.

MITOSIS Prior to mitosis, chromosomes and their DNA

replicate. Each DNA molecule produced will form the

main part of a chromosome.

MITOSIS Prior to mitosis, chromosomes and their DNA

replicate. Each DNA molecule produced will form the

main part of a chromosome. Each replicated chromosome is called a

chromatid; these are held together by the centromere.

**Stick the diagram into your book**

MITOSIS Prior to mitosis, chromosomes and their DNA

replicate. Each DNA molecule produced will form the

main part of a chromosome. Each replicated chromosome is called a

chromatid; these are held together by the centromere.

Each of the cells formed in mitosis are genetically identical (unless an error (mutation) has occurred.

ASEXUAL REPRODUCTION One individual creates a genetically identical

copy of itself without any genetic material from another individual.

ASEXUAL REPRODUCTION One individual creates a genetically identical

copy of itself without any genetic material from another individual.

These new individuals arise by mitosis

ASEXUAL REPRODUCTION One individual creates a genetically identical

copy of itself without any genetic material from another individual.

These new individuals arise by mitosis Asexual reproduction is typically rapid,

producing many offspring – this allows individuals or the population to take advantage of favourable conditions.

ASEXUAL REPRODUCTION One individual creates a genetically identical

copy of itself without any genetic material from another individual.

These new individuals arise by mitosis Asexual reproduction is typically rapid,

producing many offspring – this allows individuals or the population to take advantage of favourable conditions.

As all of the population are genetically identical, the only possible variation in DNA is mutation.

ASEXUAL REPRODUCTION One individual creates a genetically identical

copy of itself without any genetic material from another individual.

These new individuals arise by mitosis Asexual reproduction is typically rapid,

producing many offspring – this allows individuals or the population to take advantage of favourable conditions.

As all of the population are genetically identical, the only possible variation in DNA is mutation.

There is no genetic variation present to help the population if there is an environmental change.

MEIOSIS AND SEXUAL REPRODUCTION Meiosis – cell division which produces the sex

cells/gametes

MEIOSIS AND SEXUAL REPRODUCTION Meiosis – cell division which produces the sex

cells/gametes This occurs in the cells of the reproductive

organs (sperm in the testes, ova/eggs in the ovaries)

MEIOSIS AND SEXUAL REPRODUCTION Meiosis – cell division which produces the sex

cells/gametes This occurs in the cells of the reproductive

organs (sperm in the testes, ova/eggs in the ovaries)

Gametes are produced in sexual reproduction – this involves fertilisation – the process of two gametes (male and female) combining.

MEIOSIS AND SEXUAL REPRODUCTION Meiosis – cell division which produces the sex

cells/gametes This occurs in the cells of the reproductive

organs (sperm in the testes, ova/eggs in the ovaries)

Gametes are produced in sexual reproduction – this involves fertilisation – the process of two gametes (male and female) combining.

Sexual repro is slower than asexual, and fewer offspring produced at a time.

MEIOSIS AND SEXUAL REPRODUCTION Meiosis – cell division which produces the sex

cells/gametes This occurs in the cells of the reproductive

organs (sperm in the testes, ova/eggs in the ovaries)

Gametes are produced in sexual reproduction – this involves fertilisation – the process of two gametes (male and female) combining.

Sexual repro is slower than asexual, and fewer offspring produced at a time.

However, all offspring are genetically variable – increasing their chance of survival when the environment changes.

MEIOSIS DNA replicates before cell division; thus the

chromosomes replicate. These replicated chromosomes come together in their homologous pairs.

MEIOSIS DNA replicates before cell division; thus the

chromosomes replicate. These replicated chromosomes come together in their homologous pairs.

Each pair is separated in the first division, then each chromatid is separated in the second division.

***Stick diagram into your books***