Cytogenics (Cram)

The two processes by which cells and organisms reproduce themselves for normal functioning

1. Meiosis

2. Mitosis

What does DNA stand for?

Deoxyribonucleic acid

The long strands of DNA are organized into what units within a cell's nucleus?

Chromosomes

Fill in the blank: Specific sections of DNA called _____ occur at specific locations on the chromosomes.

genes

What are the two phases of the cell cycle?

1. Interphase
2. Mitosis

What phase of the cell cycle is this? The cell grows, it replicates DNA, duplicates chromosomes, carries out normal metabolism, and organelles duplicate

Interphase

Note: This was once thought to be a resting phase

Label A-E on this diagram of DNA

A - Nucleus
B - Chromosome
C - Centromere
D - Sister chromatids
E - Gene

What phase of the cell cycle is this? It is the process of replicating the nucleus and dividing of the cell cytoplasm

Mitosis

Note: Dividing of the cell cytoplasm is specifically called cytokinesis

What are the four distinct phases of mitosis?

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

A special type of cell division by which the new cells created have half of the normal chromosome number of the species

Meiosis

Specialized reproductive cell capable of entering into a union with another in the process of fertilization

Gamete

Female gamete

Ovum

Male gamete

Sperm

Fill in the blank: The process of meiosis consists of ____ [#] replication of nuclear material in the cell, as in mitosis, followed by ____ [#] successive cell divisions. Each division reduces the number of chromosomes by half.

1, 2

Note: This means that in mitosis the cell goes through PMAT once, while in meiosis the cell goes through PMAT twice

Term that describes the relative number of chromosomes the four gametes produced during meiosis have

Haploid (n)

Note: This means that gametes contain half the chromosomes of a normal body cell

Term that describes the relative number of chromosomes the two cells produced during mitosis have

Diploid (2n)

Note: This means that the cell produced has the same number of chromosomes as every other body cell

Meiosis is divided into two stages: Meiosis I and Meiosis II. In which stage does DNA replication take place?

Meiosis I, not meiosis II

In meiosis chromosomes of the same approximate size and with genes on the same locations are paired and "cross over", exchanging pieces of themselves. What do we call these chromosomes?

Homologous chromosomes

True or false: In the female, during the formation of the ovum, the division of the cytoplasmic material is very unequal during both meiotic divisions

True

Only one large haploid ovum is produced from a single diploid parent cell, what are the other three cells produced called?

Polar bodies. These eventually degenerate

What type of reproduction is used by bacteria and protozoa?

Asexual reproduction

Note: Some forms of life are capable of both sexual and asexual production (ie. protozoal parasites and coccidia)

What are the four forms of asexual reproduction?

1. Binary fission
2. Budding
3. Fragmentation
4. Multiple fission

What form of asexual reproduction is this: It occurs when the nucleus divides repeatedly before the division of cytoplasm, thus giving rise to many daughter cells almost simultaneously

Multiple fission

Example: Protozoa

What form of asexual reproduction is this? It involves the parent dividing into two equal parts, each of which grows into an individual similar to the parent

Binary fission

Example: Bacteria

What form of asexual reproduction is this? It occurs when an individual arises as an outgrowth from the parent. It is an unequal division

Budding

Example: Yeast

What form of asexual reproduction is this? It occurs when an organism breaks into two or more parts, each capable of becoming complete new individuals

Fragmentation

Example: Flatworms