1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jeka57 [31]
3 years ago
12

A normal human karyotype has

Biology
2 answers:
omeli [17]3 years ago
8 0

A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species or in an individual organism and for a test that detects this complement or measures the number.

What Is a Karyotype?

A karyotype is simply a picture of a person’s chromosomes. In order to get this picture, the chromosomes are isolated, stained, and examined under the microscope. Most often, this is done using the chromosomes in the white blood cells. A picture of the chromosomes is taken through the microscope. Then, the picture of the chromosomes is cut up and rearranged by the chromosome’s size. The chromosomes are lined up from largest to smallest. A trained cytogeneticist can look for missing or extra pieces of chromosome.

karyotype[1]There are 22 numbered pairs of chromosomes called autosomes.  The 23rd pair of chromosomes are the sex chromosomes.  They determine an individual’s sex.  Females have two X chromosomes, and males have an X and a Y chromosome.

How are the Chromosomes Numbered?

Each chromosome has been assigned a number based on its size. The largest chromosome is chromosome 1. Therefore chromosome 18 is one of the smallest chromosomes in humans.

Human karyotypes: 2n = 48 or 46?

   Early studies of the human karyotype simply stained chromosomes within cells with Giemsa and "squashed" them between the cover slip and slide. Most cells were not at the proper mitotic phase for chromosomes to be observed, and chromosome separation was poor. The exact count was uncertain: most workers accepted the number 48. The breakthrough came in 1952 (left) when a technician in the lab of T. C. Hsu accidentally substituted distilled water for the normal saline solution used in washing the cells just before "squashing". This "hypotonic" treatment caused the cell nuclei to swell, and allowed the chromosomes to separate before squashing. A further refinement was "dropping" the cells onto the slide at arm's length, which caused the nuclei to burst on impact, further separating them (middle slide). Finally, the use of a plant spindle-poison Colchicine allows chromosomes to be arrested at mitotic metaphase, during their maximum state of compaction [right] These experiments quickly established the human chromosome number as 2n = 46 chromosomes.  

   Classification of  chromosomes into seven groups by size and relative centromere position established the so-called "Denver System" (right) in 1960. Chromosomes within groups B - G were not readily distinguishable from each other. The X chromosome is in the C group, and the Y is in the G group: males are reconizable by five small G-type chromosomes. Modern banding techniques allow each chromosome in the karyotype to be distinguished individually.

Alborosie3 years ago
8 0
It has 46 chromosomes or 23 pairs. The last pair(23rd) would be the sex chromosomes which differ in men(xy) and women(xx).
You might be interested in
Red blood cells,carrying dioxide(a waste product of cellular respiration) travel in the blood vessel to the lung; to get rid of
alexandr1967 [171]

Answer:

True.

Explanation:

Red blood cells or erythrocytes carry oxygen to the cells of the body so that they can have energy and function properly. This is not the only function of red blood cells. Also, they carry dioxide, which is a waste product that needs to be out of our body. Erythrocytes carry the dioxide to the lungs, specifically to the alveoli. In the alveoli due to the inhalation, oxygen enters our body traveling up to the lungs, specifically to the alveoli, where thanks to the thin wall of it as well as the one on the capillaries that are in contact with it, the dioxide enters the lungs to be expelled in the exhalation, and the oxygen is taken by the red blood cells to be used in the cellular respiration and generate energy to keep the vital functions of our body.

3 0
3 years ago
? 3. Explain why Surtsey provided ideal conditions for studying primary succession:
Delicious77 [7]

Answer:

Due to newly formed land.

Explanation:

Surtsey provided ideal conditions for studying primary succession because due to volcanic eruption all the vegetation and living organisms are destroyed from the surface and the land has no vegetation. Primary succession only occurs when the land is colonized for the first time after the formation of land due to natural disaster such as volcanic eruption etc. So we can say that Surtsey provided the conditions for observing primary succession.

4 0
3 years ago
What kind of effect can a chromosomal change can have on an organism?
SOVA2 [1]

Answer:

<u>positive, negative, or no effect</u>

Explanation:

The kind of effect that a chromosomal change can have on an organism is either positive, negative, or no effect.

The 3 main chromosomal disorders seen in humans are :

  1. <u>Down's Syndrome</u>
  2. <u>Klinefelter's Syndrome</u>
  3. <u>Turner's Syndrome</u>
6 0
2 years ago
_______ are filtering points throughout the body which act to filter bacteria and other large particles from the spaces between
Maurinko [17]
D. Lymph nodes are the filtering points throughout the body... found in the lymphatic system
4 0
3 years ago
How are photosynthesis and respiration related to each other?
Pavel [41]
The answer is B.
It describes the relationship between photosynthesis and respiration accurately.
3 0
2 years ago
Other questions:
  • Within systemic capillaries, substances such as oxygen, hormones, and nutrients move by ____________ from their relatively _____
    5·1 answer
  • A biochemist isolate, purifies, and combines in a test tube a variety of molecules needed for dna replication. when she adds som
    12·1 answer
  • Are there striations across the width of muscle cells?
    9·1 answer
  • Termites are unable to digest some plant materials (fiber). Termite stomachs contain bacteria that digest the fiber in wood. Whi
    6·1 answer
  • Damage to the ________ neurons of the forebrain would be expected to ________ aggressive attack.
    15·1 answer
  • Could someone help? :)
    11·1 answer
  • AG CLASS
    14·1 answer
  • All of your cells except sperms and eggs have all of your dna in them <br><br> True or false
    9·1 answer
  • 1. What phenotypes would you predict in the F2 generation?​
    5·2 answers
  • How is real life fingerprinting different from the techniques used on CSI?
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!