Answer:
Genes coding for proteins involved in chiasma formation.
Explanation:
Chiasma is the connecting link between two non sister chromatids from homologous chromosomes. At chiasma chromosomal crossover takes place in which the genetic material is exchanged between the chromatids. During meiosis aneuploidy occurs if chiasma is absent or impaired due to a mutation in genes encoding for proteins involved in chiasma formation.
Aneuploidy is characterised by presence of abnormal number of chromosomes in cells. They can be 45 or 47 in number apart from the usual 46. Due to impaired chiasma, chromosome pair fails to separate and is passed on to the egg or sperm as it is hence there is one gamete with an extra chromosome and one gamete with a less chromosome. Aneuploidy can result in many genetic disorders like three copies of chromosome 21 can result in Down syndrome.
A characteristic classified as a special impact
Answer:
The <u>nuclear envelope</u> is composed of two concentric lipid bilayer membranes separated by an intermembrane space of about 20-40 nm. The outer membrane is continuous in many places with the rough endoplasmic reticulum. Like the rough ER the outer membrane of the nuclear envelope is dotted with ribosomes.
D is correct. Cool air sinks, which forces warm air to rise.
Convection is when warm material rises and cool material sinks
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