Leaving Cert Biology Revision

Explain the term Cell Continuity

• Cells divide for reproduction

• All cells develop from pre existing cells

• Each organism has a characteristic number of chromosomes

Cells divide for 2 purposes:

• Energy & Reproduction

• Replication of cellular genetic material

• Reproduction & repair/ growth of multicellular organisms

How are sexual reproduction and asexual reproduction different from each other?

• Asexual reproduction requires two parents and sexual reproduction requires only one parent.

• Mutation rates are lower in sexual reproduction than in asexual reproduction

• Asexual reproduction occurs only in multicellular organisms

• Sexual reproduction requires two parents and asexual reproduction requires only one parent.

Explain the term diploid

• When a cell has one copy of each chromosome

• When a cell has two copies of each chromosome

• An example -sex cells

Explain the term haploid

• A cell contains one copy of each chromosome

• A cell containing two copies of each chromosome

• An example : human cell 46 chromosomes

Chromosomes are:

• Found in Ribosomes containing Protein

• Genetic material composed of only DNA

• Found in the nucleus, composed of Protein and DNA

• Interphase

• Prophase

• Anaphase

• Telophase

• Metaphase

Place these cells in order of mitosis.

• A, B, C, D, E

• C, E, A, D, B

• C, E, D, A, B

• E, C, A, D, B

• Prophase

• Anaphase

• Cytokinesis

• Telophase

Human eggs and sperm are _____, and each has ____ chromosomes.

• Diploid, 23

• Haploid, 23

• Diploid, 46

• Haploid, 46