Biology Chapter 12: Reproduction

Runners, Stolons

(for example-- strawberries) -spreads along the ground

Cuttings

(in plants) 1 piece develops its own roots ----Plant cutting, also known as striking or cloning, is a technique for vegetatively (asexually) propagating plants in which a piece of the stem or root of the source plant is placed in a suitable medium such as moist soil, potting mix, coir or rock wool.

Sex cells or Gametes have how many sets of chromosomes?

1 set or in total 23 chromosomes (haploid- 1n)

haploid

1n

How many sets of chromosomes do Somatic cells have?

2 sets of chromosomes

sex cells/ gametes # of chromosomes

23

In humans somatic cells have what?

23 pairs or in total 46 homologous chromosomes -- diploid (2n)

diploid

2n

Trisomy

3 chromosomes instead of a pair or 2 (this is in autosome #21) this is a disorder for down syndrome

human cells/somatic cells # of chromosomes

46

autosomes

An autosome is a chromosome that is not an allosome (a sex chromosome). Autosomes appear in pairs whose members have the same form but differ from other pairs in a diploid cell, whereas members of an allosome pair may differ from one another and thereby determine sex.

Types of Asexual reproduction:

Binary Fission- 2 cells each with 1 chromosome, only in prokaryotes Mitotic Cell Division- 2 cells with same chromosomes as parent, only in unicelled eukaryotes EX: protozoa Vegetative reproduction- no specialized reproductive structures used: budding, fragmentation, cuttings, runners, stolons, unfertilized bee eggs

Budding

Budding is a form of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. The new organism remains attached as it grows, separating from the parent organism only when it is mature, leaving behind scar tissue. -- yeasts and hydra (like in freshwater, tentacles, double DNA)

Results of Meiosis in sex cells:

In Males: 4 sperm cells are produced In Females: 1 egg(ovum) and 2 polar bodies

difference between mitotic cell division and meiotic cell division

Meiosis and mitosis are both preceded by one round of DNA replication; however, meiosis includes two nuclear divisions. The four daughter cells resulting from meiosis are haploid and genetically distinct. The daughter cells resulting from mitosis are diploid and identical to the parent cell.

The production of an egg in meiosis is called what?

Oogenesis

What happens during Prophase I ???

Pieces of chromatids break off and exchange places with the same part of the homolog (crossing over).

The number of eggs produced by the ovaries is related to WHAT?

The method of fertilization and development- more are produced if either or both are external... species survival

Why is only 1 female egg produced in meiosis?

The ovum (egg) needs more cytoplasm after fertilization

Mitotic Cell Division

The process in cell division by which the nucleus divides, typically consisting of four stages, prophase, metaphase, anaphase, and telophase, and normally resulting in two new nuclei, each of which contains a complete copy of the parental chromosomes. There are 2 cells with same chromosomes as parent. This takes place in unicelled eukaryotes.

What happens to unfertilized bee eggs?

They develop into males drones that mate with the queen bee.

Example of Nondisjunction:

Trisomy

example of monosomy

Turner's syndrome

Vegetative reproduction

Vegetative propagation is a form of asexual reproduction of a plant. Only one plant is involved and the offspring is the result of one parent. The new plant is genetically identical to the parent. NO specialized reproductive structures used:

Turner's syndrome

XO- only one X chromosome and no Y chromosome. Sex is female

zygote

a fertilized egg, a female's egg that has been fertilized by a male's sperm

Reproduction

a life process of passing genetic material to future generations

gonads

an organ that produces sex cells/gametes : ovaries and testes

External Fertilization

aquatic (releases large amounts of sex cells into water- spawning) some amphibians and fish together release sperm on eggs in water hoping that the eggs will be fertilized

somatic cells

body cells --A somatic cell is any cell of the body except sperm and egg cells. Somatic cells are diploid, meaning that they contain two sets of chromosomes, one inherited from each parent.

Earthworms and hydra produce both

but 2 parents unite

meiosis

cell division which produces haploid chromosomes in 4 sex cells/gametes (egg or sperm) by dividing twice, but only replicating once. ---a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells - sperm in males, eggs in females. During meiosis one cell? divides twice to form four daughter cells.

nondisjunction in chromosomes/karyotypes:

chromosomes that fail to separate in meiosis

ovum

female sex cell or egg

sex cell

gamete

Fragmentation

is a form of asexual reproduction or cloning in which an organism is split into fragments. Each of these fragments develop into mature, fully grown individuals that are clones of the original organism. These worm like things break into pieces and each piece equals a new offspring. ALSO KNOWN AS----- Regenteration EXAMPLE: planaria and starfish

Binary Fission

is a kind of asexual reproduction. It is the most common form of reproduction in prokaryotes and occurs in some single-celled eukaryotes. After replicating its genetic material, the cell divides into two nearly equal sized daughter cells. The genetic material is also equally split.

karyotype

is the number and appearance of chromosomes in the nucleus of a eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.

Crossing Over allows what?

it allows variation in species by genetic recombination.

Internal Fertilization

land animals release sperm into females- protection requires fewer amounts

sperm

male sex cell or gamete

asexual reproduction

reproduction with just one parent (1) all offspring are identical (clones of each other)

sexual reproduction

reproduction with two parents combining genetic material --varied offspring due to each parent giving 1 sex cell (gamete); Each gamete (sex cell) has only 1/2 the number of chromosomes as the somatic (body) cells. offspring can have different appearances, sex, etc.

gamete

sex cell

The production of sperm in meiosis is called what?

spermatogenesis

Fertilization

union of ovum (egg) and sperm from gonads (ovaries and testes) returns cell to diploid- normal 46 chromosomes 23+23=46

Klinefelter's Syndrome

when there is 2 XX and 1 Y 2 female sex cells and 1 male sex cell The sex is-- male because y=male

Monosomy

when there is only 1 sex chromosome