Showing posts with label Cell division. Show all posts
Showing posts with label Cell division. Show all posts

The reasons for Mendel's selection of pea plant to conduct his genetic experiments.. A female hermaphrodite contains male and female organs

The reasons for Mendel's selection of pea plant to conduct his genetic experiments:

1- Shorten their life cycle (generation).

2 - containing several pairs of contrasting qualities such as the length and the short and white and red color.

3 - the possibility of self-vaccination (a female hermaphrodite containing male and female organs).

Cell life cycle.. The successive stages of growth and division that occur to the cell in the period between two consecutive divisions. Interstitial phase. Develop cellular division

The cell life cycle is the successive stages of growth and division that occur to the cell in the period between two consecutive divisions.
The cell life cycle consists of two phases:
First: Inter-phase:
It takes 90% of the session time and includes three periods:
** First growth period (doubling of membership)
** Construction period (DNA multiplication)
** Second growth period (rapid growth in preparation for division).
Second: the phase of cellular division:
There are two types of division:
1 - indirect division.
2 - the reduction of the reduction.

Chemical Composition of Chromosomes.. Nucleic acid. Protein (histones). Khaitan connected together centrometer

Chromosome shape:
  A darkened form of filament is found inside the nucleus.
Chemical Chromosome Installation:
** DNA.
** Protein (histones).
Molecules are called genomes.
General chromosome installation:
It is composed of two threads connected together by the centrometer and each string called chromatide, called the end of the chromosome arms of the terminal granules.

The stages of indirect cell division.. Primer phase. Tropical phase. Secessionist phase. The final stage

Preliminary phase:
1. Chromosomes are characterized within the nucleus (shorten and thicken).
2. Chromosomes multiply by forming chromatides linked by the centrometer.
3 - disappear the nucleus and fade the nuclear membrane.
4. The central body of the animal cell is divided into two sections to be spindle threads.
NB The plant cell does not contain a central body.
Tropical phase:
1. Spindle lines are formed and the chromosomes move to the equatorial region.
2. Chromosomes are linked to spindle threads by centrometers.
The separatist phase:
1. The centrometer is divided and the chromatid is separated and directed to the electrodes.
2. The spindle threads shrink, and each pole has two sets of chromatids (now called chromosomes).
Final stage:
1 - The cell is divided into two cells that suffocation occurs in the middle of the cell and continue until the cell is divided.
2. Each section contains a nucleus, and the cell moves into the standby role for another indirect division.

Diastolic cell division in reproductive cells.. Split the sperm in the testis and ovary in the ovaries and pollen in the mitochondria

Where does the mezzanine divide occur?
In the reproductive cells are found the reproductive cells in:
A. Animal:
1 - testicular: And result from the division of sperm (masculine spleen).
2 - Ovary: The result of the division of the egg (female spleen).
B - Plant:
1 - Mtk: The result of the split pollen (masculine spleen).
2 - Ovary: The result of the division of the egg (female spleen).

Metabolic cell division.. Exchange or transit of genes between each opposite chromatidine. A nuclear and nuclear membrane in each pole and separation into two cells with half the number of chromosomes

The meiosis is divided into two parts:
- The first division: It passes through four stages:
Phase I:
1. Chromosomes are characterized by shortening and amplification.
2. Each chromosome chromosome, called the pair of chromosomes in the quadrilateral (4 chromatids), is mixed in similar pairs.
3. Gene exchange or transit occurs between each opposite chromatidine in the quaternary (transit phenomenon).
4. The nuclear membrane disappears and the nucleus, and every chromosome in the quartet begins to move away from each other.
First tropical phase:
Binary chromosomes on the equator are linked to the spindle threads.
 The first separatist phase:
The spindle leads shrink, leading to half the chromosomes going to the pole and the other half to the other pole of the cell.
Final Phase I:
Each pole consists of a nuclear and nucleic membrane and then splits into two cells with half the chromosomes.
Second division: After the two cells in the meiosis, the two cells divide indirectly to give four cells with the same number of chromosomes, and these resulting cells are called gametes.
Chapter II: Non-sexual reproduction in living creatures.

Non-sexual reproduction.. Reproduction with bilateral fission. Reproduction with sprouts. Reproduction by forming spores. Reproduction by regeneration. Reproductive reproduction. Vegetative propagation

Definition: The production of new individuals have the same characteristics of the origin of a parent and without the formation of sexual cells.
Types:
First: Reproduction with bilateral fission:
- The cell is divided into two cells and occurs in single-cell organisms.
- such as bacteria (transverse), such as primates such as bramacium (transverse) and igloina (longitudinal).
Second: Reproduction with sprouts:
- The emergence of a bud (protrusion) on the side of the cellular wall grows gradually.
- occurs in some fungus (yeast) and some of the digestive (hydra).
Third: Reproduction by spawning:
- Cells called spores are formed within bogus portfolios (harsh environmental conditions).
- occurs in lichens, fungi and algae.
Explain the example of mushroom bread mold:
Spores are formed in portfolios and carry the caps on the pregnant, and when the spores mature, they press the bags and get out and then fall to the ground, and when the appropriate environmental conditions sprout form a new.
Fourth: Reproduction by renewal:
- The ability of the organism to compensate for missing parts.
- Occurs in the thorns of the skin and sponges.
Fifth: Fertilization:
- the ability of some animals to produce non-fertilized eggs with the ability to grow to form a new individual without fertilization.
- occurs in crustaceans and some worms and insects.
Sixth: Vegetative reproduction:
It does not require the presence of seeds.

The importance of vegetative reproduction.. Maintain genetic traits and produce similar assets in their genetic makeup and maintain good mutations

The importance of vegetative reproduction:
1. Preserving the genetic characteristics of plants.
2 - multiplication of plants that are difficult to multiply with seeds.
3 - Production of large seedlings and fruit trees in a short time.
4 - Overcoming some diseases.
1. Overcoming certain environmental conditions that are not suitable for some plants.
2. Produce similar assets in their genetic composition and maintain good mutations.

Types of vegetative propagation.. Tendering. Vaccination and Installation. Transfer part of the leg of the plant to the desired breeding (bait) and paste the leg of another plant

1 - Tendering: It takes parts of the legs contain several sprouts and grown in the ground, activating the cells at the bottom of the brain and the roots of transverse sprouts grow up to be branches of air. Such as fx and deflation.
2- Vaccination and Composition:
Vaccination: The transfer of part of the leg of the plant is desirable breeding (bait) and sticks to the leg of another plant (origin).
Composition: Installation of a small part of the branch does not exceed the age of the year called the pen and put it on the leg of origin or mind of its roots.

Plant propagation with the spores.. Short side growth that comes out of the native plant close to the surface of the soil and has independent roots such as palm and banana

Phytoplankton is a short lateral growth that emerges from the native plant close to the soil surface and has independent roots, such as palm and banana.
Things to consider when separating the offspring from their mothers:
1 - avoid the large number of wounds during separation because they increase the likelihood of disease.
2 - have a radical total.
3 - to be free of diseases.

Reproduction by some plant parts developing under the soil surface.. The real parts. Tubers and tuberous roots. Rhizomes

Reproduction by some plant parts developing under the soil surface:
A) The real bulb: The bulb is a leg of a tablet with a lateral end and surrounded by the bases of the meaty leaves filled with stored food, such as onions and daffodils
B) Tubers and tuberous roots: Tubers are a mutant ground leg for storing food, such as potatoes.
C) Risomate: A reptile or creeping stalk that grows under the surface of the soil and is divided into brains and salts, such as mint and cardamom.

Reproduction through the division or fragmentation of the plant.. Cutting of the mutant plant parts, especially the stems and roots that grow under the surface of the soil

Reproduction by dividing or dividing the plant:
It is meant to cut the mutant plant parts, especially the stems and roots that grow under the surface of the soil and which have the ability, if divided into parts, to return every part of the entire plant life cycle.

The method of sexual reproduction in the berysium.. Split the parietal nucleus and all the bramysium not sexually by fission

1. Two bronchium animals sit side by side and form a protoplasmic bridge between them.
2. The large nucleus decomposes and the small splitting fraction (twice) is divided into 4 small nuclei.
3 - decomposing 3 nuclei and one remains divided into two indirectly divided into two nuclei, one small note and a large female nucleus.
4 - move a small island from each animal to the other across the arch and unite a small nucleus.
5. The animals separate from each other.
6. The macrophage nucleus is divided into several divisions to give 8 nuclei increasing in volume 4 of which are large nuclei and 4 remain small.
7. Each non-sexual bramysium is divided by fission twice to be four animals each with small nests and other large ones.
Subscribe to: Posts (Atom)