Correct answer:
"<span>B- homologous chromosomes join together to form tetrads during prophase I"
</span>It is during prophase I that homologous chromosomes join together (<span>synapsis)</span> and form tetrads - four chromatids are together in the new structure of two chromosomes - and this is the reason why crossing-over occurs in this phase. It is in this tetrad that both arms of both chromosomes may crossover and matching regions exchange places. This process results in homologous chromosomes recombination leading to genetic variability.
In Texas, this region is divided into three distinct sub-regions: the High Plains, the Edwards Plateau and the Llano Basin.
The naturally occurring solid mixture of one or more minerals and organic matter is known as a Rock.
A rock is a naturally occurring substances that is a solid mixture of one or more minerals together with organic matter.
<h2>Further Explanation;</h2>
- Rocks are classified based on the chemical composition, texture and the way they are formed. One type of rock may change from one form to another through a rock cycle.
- Rock cycle is the process through each various rocks change from one form to another, normally an interchange between the three major types of rocks.
There are three major classification of rocks:
<h3>Sedimentary rocks </h3>
- Sedimentary rocks are types of rocks that are formed through accumulation of sediments at low temperatures in tectonic layers and sinks. These sediments includes; pebbles, shells, sand and other material fragments.
- The sediments accumulates in layers and then harden into rocks over a period of time.
- Examples of sedimentary rocks include; limestone and conglomerate
<h3>Metamorphic rocks</h3>
- These are types of rocks that are formed as a result of changes that occurs due to intense heat and pressure under the surface of the earth. They result from action of heat and pressure on other rocks that pre-existed.
- These types of rocks are characterized by shiny crystals, ribbon-like layers among other features.
- Examples of metamorphic rocks are marble and gneiss
<h3>Igneous rocks </h3>
- These are types of rocks that are formed as a result hardening and cooling of magma from volcanic eruptions. Magma may cool inside the earth or when on the surface of the earth as a result of volcanic eruptions. The lava from this eruptions cools and hardens to form metamorphic rocks.
- Igneous rocks are glass-like and shiny with no crystals. They may also have tiny spaces and holes due to gas bubbles trapped during the cooling process.
- Examples of igneous rocks include obsidian and basalt.
- The three types of rocks may be further classified in terms of chemical composition, texture and formation.
Key words: Rocks, types of rocks, chemical composition
<h3>Learn more about;</h3>
- Rocks and rock types; https://brainly.in/question/5987245
- sedimentary rocks; https://brainly.in/question/3259075
- igneous rocks; https://brainly.in/question/272012
- metamorphic rocks; https://brainly.in/question/1206219
Level; High school
Subject: Geography
Topic: Rocks
sub-topic: classification of rocks
