All categories

3 years ago

What is parthenogenesis? give an example

Biology

1 answer:

ANEK [815]3 years ago

3 0

Answer:

It's a form of asexual reproduction!

Development of the offspring happens without fertilization in this type of reproduction.

The two main ways in which parthenogenesis happens is by apomixis or automixis. Through apomixis , the egg cells are produced by mitosis. Through In automixis, egg cells are produced by meiosis.

Mitosis = a part of cell cycle: replicated chromosomes are separated into 2 nuclei

Meiosis = type of cell division that reduces the chromosome number by half. So now there is four haploid cells that are genetically distinct from their parent cell.

Example:

An example of an animal that can use this reproduction is a bonnethead shark! Once a shark had a baby in a tank that only had three females!

(read about that on wikipedia)

You might be interested in

Which of the following processes helps to cycle carbon between water and air?

astraxan [27]

Answer: The correct answer is Diffusion.

The molecules of carbon dioxide enter the oceans through the process of diffusion into the surface of sea water and dissolve by a physio-chemical process. The factors affecting the amount of carbon dioxide diffusion includes wind, concentration of carbon dioxide, temperature of the water etc. The carbon dioxide which diffuses into the oceans reacts with water forming carbonic acid, carbonate and bicarbonate ions. The gaseous form of carbon dioxide in atmosphere is converted to non-gaseous form reduces the carbon dioxide pressure in the water and promotes more diffusion from the atmosphere.

7 0

4 years ago

If water vapor continue to increase in our atmosphere of what changes would you expect in freshwater lakes

Jobisdone [24]

Lake temperatures will increase but dissolved oxygen in the water will decrease. Water vapour is a potent greenhouse gas, so global temperatures will increase, including lake temperature. Additionally, increased water vapour in the air will decrease the amount that can evaporate from the lake and further reduce the amount that it can cool, in which makes the water warmer still. Water temperature increases mean decreased the solubility of gases (above 4 degrees C), so dissolved oxygen would cease to decrease on a ppm basis. I hope this answer has helped you.

7 0

3 years ago

Read 2 more answers

David has sustained an injury to his neck that has resulted in the complete loss of sensation to the posterior side of his upper

slavikrds [6]

Answer;

Radial nerve

Explanation

-The nerve that is most likely to be damaged as a result of his injury is the radial nerve.

-The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb.

-It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.

4 0

3 years ago

What is a qualitative observation

lisabon 2012 [21]

Answer:

Qualitative observation is an observation in which the apperance of something is described using descriptive language

Explanation:

Qualitative observation is done to test the quality or purity of a substance being examined.

Qualitative observation is based on nonnumerical information.Qualitative analysis helps us to study whether a particular functional group,ion or atom is present or absent in a given sample.

7 0

3 years ago

The trp and lac operons are regulated in various ways. How do bacteria regulate transcription of these operons? Sort the stateme

OLEGan [10]

Answer:

Operon is not transcribed:

-lac operon: lactose absent

-trp operon: tryptophan present

Operon is transcribed, but not sped up through positive control:

-lac operon: lactose and glucose present

-trp operon: tryptophan absent

Operon is transcribed quickly through positive control:

-lac operon: lactose present, glucose not

Explanation:

The trp operon is controlled via negative control only.

Presence of tryptophan will inhibit the transcription of the operon genes

The lac operon is controlled via negative control and positive control.

●Negative control:

--Transcription is turned off due to

active Repressor protein and absence of lactose

--Transcription is turned on due to

Inactive Repressor protein and presence of lactose

●Positive control:

--Transcription rate is higher due to absence of transcription and presence of lactose as a regulatory protein (CAP) adhere to the lac operon promoter

8 0

3 years ago