What are the two ways cross pollination can occur?

A substance prepared from killed or weakened pathogens that is introduced into the body to stimulate an immune response is known

snow_lady [41]

The hepatitis B and the human papillomavirus (HPV) vaccines are made this way. The vaccine is composed of a protein that resides on the surface of the virus. This strategy can be used when an immune response to one part of the virus (or bacteria) is responsible for protection against disease.Jun 28, 2016

3 0

3 years ago

Meiosis Foldable Activity 515.2

Aleksandr-060686 [28]

Explanation:

During the process of prophase I, the nuclear envelope containing chromosomes has only partly broken down homologous chromosomes are joined together by proteins and a complex or pairing call synapsis- corresponding genes on sister chromatids are aligned precisely.

The syanapsis allows for crossing over which is the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.

Further Explanation:

All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. In meiosis, the number of chromosomes (2n) is halved to 23 chromosomes (haploid number)through meiotic divisions, producing 4 haploid (n) germ cells or gametes (sperm or eggs), each containing half the number of chromosomes as its parent cell.

In Meiosis I

homologs pair off into bivalents
At crossing over: the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined in prophase I forming bivalents; tetrads are formed.
Spindle fibers from centrioles join sister chromatids together at their centromeres in metaphase I, pulling them to the equator of the cell;
then, in anaphase I, while joined, they are pulled to opposite sides of the cell; the cell body splits and the nuclear envelope reforms in telophase I

In Meiosis II...

Later, in prophase II, the nuclear envelope disintegrates and mitotic spindle fibers are formed
independent assortment occurs. in metaphase II of meiosis: spindle fibers attach to centromeres, chromatids align independently at the equator. Genes segregate independently into new combinations as sister chromatids are pulled apart by their centromeres in anaphase II
in telophase II the cells' nuclei and membrane are then formed with each containing the haploid number (n)
Following the formation of gametes in the last stage, randomized fertilization occurs in sexual reproduction sperm cells fertilize an ovum to form a zygote. This occurs randomly by chance, to result in a complete set of chromosomes 2n, that is a novel combination of half each parent's number of chromosomes

Learn more about mitosis at brainly.com/question/4303192

Learn more about transcription at brainly.com/question/11339456

Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316

#LearnWithBrainly

4 0

3 years ago

There are no known motor proteins that move on intermediate filaments (IFs).

Harlamova29_29 [7]

Answer: The correct option is E ( Intermediate filaments are unpolarized).

Explanation:

Intermediate Filaments are usually associated with cells that can withstand mechanical stress which includes claws of animals, hair and makes up the dead remnants of the epidermal cell of the skin. Therefore without the supporting network of intermediate filaments, an epithelium remains intact but the cells are prone to damage by abrasive forces.

Intermediate filaments are so named because they are thicker than actin filaments and thinner than microtubules or muscle myosin filaments

The properties or characteristics of an intermediate filaments that explains the lack of motor proteins is as a result of its subunits which are elongated, not globular and are associated in an anti-polar manner. Therefore, the overall filament has no polarity, and therefore no motor proteins move along intermediate filaments

5 0

3 years ago

A cross section of a flower is shown below:

Marina86 [1]

The anther and filament, the anther produces pollen. They are the parts of the male reproductive organ in a flower.

<h3>What are the male parts of the flowers?</h3>

The flower can be considered as the reproductive structure of flowering plants.

The anther and filaments represent the male structures of a flower, which may also contain female structures.

The stamen can be considered as the male reproductive organ because this structure is responsible for producing pollen which contains germinal cells in a flower.

Learn more about flower parts here:

brainly.com/question/3197281

5 0

2 years ago

antoniya [11.8K]

Answer:

Enzyme catalase is affected by high temperatures

Explanation:

Enzymes are organic catalysts which are protein in nature therefore they are sensitive to changes in temperature. Most enzymes have an optimum range of temperature between 35-40°c.

As temperature is increased, the optimum temperature is reached where the rate of reaction is maximum. When beef liver is boiled, hydrogen peroxide is not broken down because higher temperatures denature enzymes making them non effective.

6 0

3 years ago