To provide energy to build new cells and tissue
Answer:
A gene is a segment of DNA, a condensed DNA molecule makes up a chromosome, a chromosome is inside a nucleus, and a nucleus is contained within a cell.
Explanation:
The nucleus is a membrane-bound organelle in the cell where the genetic information is stored. The genetic information is stored in the nucleus.
This genetic information is DNA, a double-stranded molecule made of strings of nucleotides. These nucleotide sequences form genes, which are segments of DNA that code for proteins.
DNA molecules condense to form chromosomes during certain stages of the cell cycle
Transcription factors are necessary for an initiation of transcription at a regulated gene but not sufficient.
Transcription is the first step of gene expression in which DNA molecule is copied (transcribed) into RNA (mRNA) by RNA polymerase. The process of transcription is divided into three phases:
1. Initiation
• RNA polymerase with transcriptional factors bind to gene promoter Transcription factors can enhance the interaction between RNA polymerase and a DNA sequence- promoter, encouraging the expression of the gene. Such transcription factors are called activators. Otherwise, when the gene expression is inhibited, factors are called repressors and they bind to sequence –operator.
• RNA polymerase unwinds DNA double helix (transcription bubble is formed)
2. Elongation
• RNA polymerases adds nucleotides complementary to DNA
3. Termination
• RNA polymerase gets to stop codon (transcribes a sequence of DNA known as a terminator)
• Formed complementary RNA strand is released from DNA-RNA complex
Mutation rate of Gram negative bacteria is much greater than that of Gram positive bacteria.
Explanation:
The gram positive types of bacteria responsible for causing diseases in humans. It is called as Gram positive bacteria. Both the bacteria are different in structural and physical properties. It is defined as the group of bacteria’s which positive result in gram stain test.
Gram negative bacteria are the group of bacteria’s which gives negative result to the gram stain test. This classification is done according to the cell wall. The cause of common disease by Gram positive bacteria is our anthrax, diphtheria, etc.
The Gymnosperms and Angiosperms are groups of plants with seed, which means that they don’ t necessary acquire water for fertilization. These groups have made adaptations for sexual reproduction on dry land.
1) Gymnosperms (plants with the seeds are not enclosed in an ovary) have developed over the course of its evolution, structures that solved the main limitations present in the Pteridophytes in relation to sexual reproduction, in the terrestrial environment. The main changes that happened as an evolutionary adaptation to dry land are those on the seeds and pollen. The advantages of the seeds are: the storage tissue which sustains growth and a protective coat of the seeds. Seed is enveloped with the layers of hardened tissue which prevents desiccation. This is what frees reproduction from the need for a constant supply of water. <span>The sperm (male gamete) of gymnosperms</span> is enclosed in a pollen grain. Thi structure is protected from desiccation and can reach the female organs without dependence on water. Gymnosperms also developed structures called cupules to enclose and protect the ovule (the female gametophyte) which will develop into a seed upon fertilization.
2) Angiosperms are a group of plants which protect their seeds within an ovary called a fruit. Angiosperms have special evolutionary adaptations. For example, they produce their gametes in separate organs, usually in a flower, so the fertilization and embryo development takes place inside an anatomical structure. That provides a stable system of sexual reproduction largely sheltered from environmental fluctuations like water need.
