Do you think that all pollen germinates indiscriminately on all stigmas?

1 answer:

4 0

Pollen tube growth is one of the most fascinating—and essential—phenomena in the life cycle of flowering plants. After a compatible interaction between pollen grains and the stigma surface, the pollen germinates and forms the pollen tube, which grows through the stigma, style, and transmitting tract to deliver the sperm cells to the ovule."
2) Although pollens of many species germinate in simple aqueous media, stigmas do not provide satisfactory sites for the germination of most foreign pollen... Stigmas not only provide the proper conditions for the germination of pollen from their particular species, they actively inhibit the germination of pollen of many unrelated species.

You might be interested in

What would happen if humans were made of prokaryotic cells

bixtya [17]

Oooh really a interesting thing if we were made of prokaryotic cells ....
as we know, prokaryotic cells lacks nucleus and membrane bound organelles.
The majority of prokaryotic DNA is found in a central region of the cell called the nucleoid. Then we are not able to do activities like now we do bcz if we lacks a true nucleus which contains our all genetic info: we are just like prokaryotic organisms....

5 0

3 years ago

When RNA is processed in the nucleus and made ready for transfer out into the cytoplasm for protein synthesis, which of the foll

IRISSAK [1]

Answer:
Letter E - exons are cut from the strand and removed

Explanation:

Letter A and B are incorrect because the poly-A tail and guanine cap are added to the 3’ and 5’ end respectively. They aid in translation of the mRNA, while serving as protection. The poly-A tail is repeated adenine nucleotides, while the guanine cap is a modified guanine nucleotide.

Letter C is incorrect because alternative splicing is one mechanism for generating variation, and is thought to be one of the reasons for why humans have smaller genomes than other organisms and still maintain high complexity. Alternative splicing is incredibly important because it produces more than one transcript from a pre-mRNA.

Letter D is incorrect because introns are the non coding portions of the mRNA. They are excised to make a smaller mRNA transcript, and one that contains all the protein genes.

This letter E is the correct answer, because exons are the coding portions of the mRNA, and are not excised during RNA processing.

Hope that helped! If I made a mistake, please let me know.

8 0

3 years ago

Willful muscle contraction; emotions

777dan777 [17]

Its the frontal lobe. :)

8 0

3 years ago

What is the study of how the structure and function of genes interact with our environment to influence behavior called?.

Anettt [7]

Epigenetics is the study of how the structure and function of genes interact with our environment to influence behavior.

In addition to your surroundings and habits, such as what you eat and how much exercise you get, your genes play a significant part in determining your health. The field of epigenetics investigates how environmental factors and behavior may alter how your genes function. Gene-environment interactions that result in the expression of different phenotypes throughout development are the basis for the initial usage of the term "epigenetics." To turn on or off the genes that cause long-lasting alterations linked to the differentiation of various cell types, epigenetic processes are frequently used.

Epigenetics is the study of how DNA sequences are maintained as genes are controlled by cells. DNA alterations known as epigenetic changes control whether or not genes are activated.

Learn to know more about Genes on

brainly.com/question/3764946

#SPJ4

4 0

1 year ago

How are the asthenosphere and the lithosphere different?

Rashid [163]

Earths lithospere is solid and sits on top of the softer asthenosphere.

8 0

3 years ago