Science Biology - Inheritance and evolution Flashcards
Antibiotics
Antibiotics are used to treat or prevent some types of bacterial infection. They work by killing bacteria or preventing them from spreading. Antibiotics kill bacteria by stopping cell wall synthesis or even interfering with protein synthesis. (most important function in any cell, if stopped the cell is destroyed) sometimes.
Antibiotic Resistance
Some antibiotics are becoming less effective because these bacteria are mutating to become resistant to their antibiotics and through natural selection the unresistant bacteria are being killed off leaving the resistance bacteria, which means the antibiotics won’t be affective anymore.
DNA
Deoxyribose Nucleic Acid. DNA is often called the blueprint of life. Because it contains instructions needed for an organism to grow, develop survive and reproduce. In simple terms, DNA contains the instructions for making proteins within the cell, which are essential for all life.
The structure of DNA is a double Helix. It is a polymer chain made up of monomers called nucleotides which consist of a phosphate group, nitrogen base and deoxyribose sugar.
RNA
Ribonucleic Acid. RNA is single-stranded. It has the bases A-U-C-G. There are three types of RNA. rRNA, rRNA and tRNA. RNA turns genetic information into protein.
mRNA
Copies the genetic code from DNA to RNA bases. IT moves from the nucleus to the cytoplasm from the cell. This process is called transcription.
rRNA
It is located in the cytoplasm of the cell. It is the components of ribosomes and it directs the translation of mRNA into proteins. It is exported to the cytoplasm to help translate the information in messenger RNA (mRNA) into protein
tRNA
It is located in the cellular cytoplasm. Transfer amino acids to the ribosomes to assemble proteins. When a tRNA recognizes and binds to its corresponding codon in the ribosome, the tRNA transfers the appropriate amino acid to the end of the growing amino acid chain.
Nitrogenous Bases
The Nitrogenous bases in DNA are Adenine, Thymine, Guanine, Cytosine and the nitrogenous bases in RNA are Adenine, Uracil, Cytosine, Guanine.
Phosphate
It is both In DNA and RNA. It along with the deoxyribose sugar are considered the backbones of DNA, with the nitrogenous bases sticking out of them.
Deoxyribose sugar
It is both In DNA and RNA. It along with the phosphate groups are considered the backbones of DNA, with the nitrogenous bases sticking out of them.
Cell Division
A single parent cell divides into two daughter cells, each with a complete copy of the genetic material of the parent and with the capability to divide again. Cells must also divide because old cells die and need new cells to replace them. Cell division is split into three main stages: interphase, mitosis and cytokinesis
Interphase
Cell grows into its mature size, makes a copy of its DNA, and prepares for division. This is the longest stage of cell division in any cell. There are three main phases of interphase: G1, S and G2.
Interphase: G1
This is the growth phase:
Cell doubles in size
Cell produces all the structures it needs to carry out its functions (organelles replicated)
Think of this phase as the cell just living its normal life.
Interphase: S
This stage consists of the synthesis of protein and the replication of DNA:
Cell makes a copy of its DNA (replication)
This happens because the new cells needs all of the instruction for its function and survival.
Think of this phase as placing the DNA in a copy machine.
Interphase: G2
This is the stage where the cells prepare to divide:
Cell prepares to divide
Cell produces structures needed for cell division.
Think of this phase as the cell double checking everything it needs to divide.
Mitosis
During mitosis the cells copied genetic material separates, and the cell prepares to split into two cells. This allows the cells genetic material to pass into new cells. The resulting daughter cells are genetically identical.
Mitosis is the cell division of somatic cells (bodily cells) and does not include the egg cells.
Prophase
First stage of mitosis:
The nucleus disappears
Spindle fibres form in the cytoplasm
Spindle fibres attach to sister chromatids to separate the chromosomes.
Metaphase
Second stage of mitosis:
The sister chromatids are pulled to the centre of the cell
They (chromatids) line up in the middle of the cell with the spindle fibres attached to them
Anaphase
Third stage of mitosis:
The spindle fibres begin to shorten (to pull them apart)
The sister chromatids are pulled to the opposite ends of the cell.
Telophase
Last stage of mitosis:
Where the sister chromatids arrive at the opposite poles of the cell and begin to unravel
New nucleus begins to form.
Cytokinesis
This is the last stage of the cell division process:
The division of the cytoplasm
Results in two separate daughter cells with identical nuclei.
Meiosis
Is a type of cell division that reduces the number of chromosomes in the parent cell by half (or produces a haploid number of chromosomes. Haploid chromosomes = 23 chromosomes) and produces four gamete cells.
The process is required to produce egg and sperm cells for sexual reproduction. During reproduction, when the sperm and egg unite to form a single cell, the number of chromosomes is restored in the offspring.
Meiosis 1
1 parent cell splits into two
Chromosomes are replicated to form sister chromatids. Sister chromatids are genetically identical and joined at centromere.
Prophase 1
Homologous chromosomes become closely associated in synapsis
Crossing over occurs. Crossing over is a complex series of events in which DNA segments are exchanged between Non sister or sister chromatids.
Metaphase 1
In metaphase I, the homologous pairs of chromosomes line up in the middle of the cell.
Anaphase 1
Homologous pairs of chromosomes split to either poles of the cell. Sister chromatids stay together. Basically if there are two pairs of chromosomes then either pair gets dragged by the spindle fibres to either end of the cell.
Feature 2 of meiosis.
Crossover: Parts of the chromatid in each chromosome swap. It kind of makes a remix version of the chromosome.
Telophase 1
The cell splits into newly formed cells. These cells are haploid. Each chromosome pair in the cells has non identical sister chromatids.
Meiosis 2
2 parent cells split into a total of 4 daughter cells. Meiosis 2 follows similar steps to mitosis. Meiosis 2 starts with 2 diploid cells with 2 pairs of chromosomes and sister chromatids that are non-identical.
Zygotes
Zygote, fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm). As a results, a zygote contains a diploid number of chromosomes (46).
Gametes
A gamete is the male or female reproductive cell that contains half the genetic material of the organism. When two human gametes meet — that is, a sperm cell and an ovum — you get a zygote, a fertilized egg.
Somatic Cells
A somatic cell is any cell that makes up an organism, except for a reproductive cell.
Haploid
Haploid is the term used when a cell has half the usual number of chromosomes. 23 chromosomes for humans.
Diploid
In diploid cells, one set of chromosomes is inherited from the individual’s mother, while the second is inherited from the father. Contains a total of 46 chromosomes like most human beings.
Animal cell
Has all the normal cell organelles as a plant cell except:
Chloroplast
Cell wall
Large vacuoles.