Explain the pair of chromosomes and sex chromosomes, Biology

Assignment Help:

Explain the pair of chromosomes and Sex Chromosomes?

Morgan also noticed that one pair of chromosomes is different in male and female flies, one of the male chromosomes being shorter and hook-shaped. He called the larger chromosomes X-chromosomes, and the shorter, hooked, homologous chromosomes Y-chromosomes. He suggested that the fly's sex is determined by whether the homologous pair is XX, for females, or XY, for males. Exceptions exist in birds, where the pattern is reversed--females are XY and males are XX. In some insects, where males are XO and females are XX.

In meiosis in most organisms, since males are XY, male gametes receive either an X or a Y chromosome. Since female gametes can receive only X sex chromosomes, when male and female gametes fuse, the probability is that half of the offspring will be male, and half of the offspring will be female.

Autosomes, or non-sex chromosomes, are designated by the letter A, and the letter O is used when the chromosome is missing. Humans have 22 pairs of autosomes and one pair of sex chromosomes.

 


Related Discussions:- Explain the pair of chromosomes and sex chromosomes

Discuss in detail about the human brain, Discuss in detail about the human ...

Discuss in detail about the human brain  "wiring-up" of our brain begins in early development. When our genetic blueprint largely drives this wiring in womb, a newborn baby's b

Male reproductive disorders, MALE REPRODUCTIVE DISORDERS Generally, ab...

MALE REPRODUCTIVE DISORDERS Generally, about 5-10% of cattle bulls reaching sexual maturity would be suffering from poor reproductive efficiency or sterility. Crossbreeding ha

Elaborate evolution by natural selection , Elaborate Evolution by Natural S...

Elaborate Evolution by Natural Selection ? The conelaboratecept of natural selection lies at the heart of Darwin's Theory of Evolution. Darwin understood that plants and animal

Viruses, are viruses cellular organisms

are viruses cellular organisms

The first carbon having 2 h atoms, Given a polymer backbone of H-C-C with t...

Given a polymer backbone of H-C-C with the first carbon having 2 H atoms attached and the 2nd carbon with 3 atoms attached, a bond with a water molecule attaches to the left H atom

Define protein requirement for cancer patients, Define Protein Requirement ...

Define Protein Requirement for Cancer Patients? Both the metabolic stress of cancer, as well as, chemotherapy results in increased tissue catabolism. Hypoalbuminemia and anaemi

Define eye balling, Q. Define Eye Balling? Ans. Two-dimensional ec...

Q. Define Eye Balling? Ans. Two-dimensional echocardiography provides a good visual perception of cardiac functions. With experience, the echocardiologist learns to percei

Acetylcholine - long term potentiation, Acetylcholine, a well known neurotr...

Acetylcholine, a well known neurotransmitter, plays a critical synaptic role in the initial formation of memory. Chemical blockage of the acetylcholine receptors makes it harder to

What is the results of congenital pulmonary stenosis, What is the Results o...

What is the Results of Congenital Pulmonary Stenosis? Early mortality for open pulmonary valvotomy in neonates varies between 6 and 10 per cent. For infants and children, surgi

Protozoa, Locomotion,nutrition and reproduction in ptotozoa

Locomotion,nutrition and reproduction in ptotozoa

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd