Crossing over at prophase I results in the linked genes (those on the same chromosome) becoming unlinked and separated. Prophase I is this first stage of meiosis, the chromosomes condense, form tetrads, and exchange DNA. The nucleolus and nuclear envelope disappear.
The 4 divisions of Gymnos:
1- coniferophyte
2- Cycadophyta
3- Ginkgophyta
4- Gnetophyta
Describe
1- Conifers : Pines , firs , redwoods
2- Coniferophyta : seeds , large
3- Cycadophyta : Tropical and subtropical
4- Ginkgophyta : Only living Meso Era survived in China .
I hope that's help !
Calories in and of themselves aren't a reliable way of describing energy density in food. It doesn't reflect what actually happens in your body (look up bomb-calorimeter for how people figure out calorie content in foods). So based on this, the question is a bit of a non-sequitur. But if you disregard that and go with a regular answer, it really depends on what kind of calories you're ingesting because foods get digested in a function of different amounts of time. Carbohydrates will get digested and converted into glucose almost immediately - being very close to 100% energy efficiency. Fats are the slowest as your body needs to produce bile in order to digest it - not enough bile = undigested fat = unused calories. Proteins are turned into either amino acids (not an energy source per se) or converted into glucose like carbs but instead through gluconeogenesis which is a less efficient form of glucose conversion than carbohydrates (since your liver/kidneys need to produce the enzymes to convert it). The efficiency of protein is likely in the range of 50-60% calories. This is just the tip of the iceberg though - your metabolism also plays a part as to how much and when these calories are either used, stored, and excreted by your body. Ever got the meat sweats? That's your body burning excess energy through thermogenesis when you eat too much protein. So it really depends why you're asking because the answer will differ for each scenario.
A segmented viral genome can facilitate rapid evolution of new viral strains.
Explanation:
The genome of the virus contains both coding and non-coding sequences. Segmented viral genomes are separate unit of nucleic acid in a virion particle and they undergo reassortment.
When the genome of the viral DNA gets segmented, the multiple DNA strands. When two infection with 2 strands of virus takes place simultaneously the two strains may get swapped or cross over. This leads to new strand and hence evolution happens.
examples of such virus are : Birnaviradae, reoviridae